MDME: MANUFACTURING, DESIGN, MECHANICAL ENGINEERING 

NON-FERROUS METALS

Non-ferrous means every metal except iron and steel. (i.e. Not mostly Fe). Aluminium is the number 2 metal. (After steel of course)

Image Video Lesson Description and Link Duration Date Download
  Non-Ferrous Metals 19:28 min 20140728  

Non-Ferrous Metals

 

There are many types of metals, the periodic table is mostly metal!

See properties of the pure metals (elements) here http://www.dayah.com/periodic/

 

Non-Ferrous metals are ones they are not based on iron. They are not magnetic and are usually more resistant to corrosion than ferrous metals.

  • Aluminium and its alloys
  • Copper, brass and bronze
  • Nickel alloys
  • Zinc
  • Tin
  • Lead
  • Titanium
  • Magnesium
  • Refractory metals: Tungsten, Iridium
  • Precious metals: Gold, Platinum, Silver
  • Special metals: Uranium, Mercury
 
Non-Ferrous Metals Overview
Name Composition Properties Uses
Aluminium Pure Metal Silver-White, soft, malleable, conductive to heat and electricity, It is corrosion resistant.  Foil, wire, chemical uses. Reflectors
Aluminium alloys-

 Copper, Manganese, etc
Ductile, Malleable, Work hardenable or heat treatable. Aircraft and vehicle parts. Boats, window frames,  packaging and insulation, pistons and cranks.
Copper Pure metal Red, tough, ductile, High electrical conductor, corrosion resistant, Can work hard or cold. Needs frequent annealing. Electrical wire, cables and conductors, water and central heating pipes and cylinders. Printed circuit boards, roofs.
Brass 65% copper +35%zinc. Very corrosive, yellow in colour, tarnishes very easily. Harder than copper. Good electrical conductor. Castings, ornaments, valves, forgings.
Brass - Gilding metal 85% copper+15% zinc. Corrosion resistant, golden colour, enamels well. Beaten metalwork, jewellery.
Lead Pure metal The heaviest common metal. Soft, malleable, bright and shiny when new but quickly oxidizes to a dull grey. Resistant to corrosion. Protection against X-Ray. Paints, roof coverings, flashings, sound deadening.
Zinc Pure metal A layer of oxide protects it from corrosion, bluish-white, easily worked. Makes brass. Coating for steel galvanized corrugated iron roofing, tanks, buckets, rust-proof paints
Zinc Alloys Zinc Lowest temperature pressure die casting alloys. Can be chrome plated. Lasts longer than mould for aluminium alloys. Door hardware, platable items, intricate castings (e.g. carburettor). Similar to Al but heavier.
Tin Pure metal White and soft, corrosion resistant. Tinplate, making bronze.
Titanium Alloyed Roughly in-between Aluminium and Steel, but has the highest strength to weight ratio. Extreme corrosion resistance Jet engine fan blades,  aerospace, high performance racing and sports equipment. Chemical resistance.

How much metal is used?

Metal
1998 world usage estimates
(1000 tonnes)
London Metals Exchange  ($)
Steel 776000 Steel
Aluminum 30106 Aluminium
Aluminium Alloy
Copper 14200 Copper
Zinc 8160 Zinc
Lead 5940 Lead
Nickel 1130 Nickel
Tin - Tin

 

Precious Metals Prices (Compare to Aug 2008)

Name Aug 2008
Gold 822.00 $US/Troy oz
Palladium 286.00 $US/Troy oz
Platinum 1436.00 $US/Troy oz
Silver 13.38 $US/Troy oz

Commodity Prices, Base Metals (Aug 2008)

Name Quote
Aluminum 1.24 $US/lb
Copper 3.52 $US/lb
Lead 0.86 $US/lb
Molybdenum 33.25 $US/lb
Nickel 9.38 $US/lb
Uranium 64.50 $US/lb
Zinc 0.81 $US/lb
Get current prices here: http://dollardaze.org/feeds/


ALLOYS 

An alloy is a solid solution or homogeneous mixture of two or more elements, at least one of which is a metal, which itself has metallic properties. 

Alloying one metal with others often enhances its properties, especially strength. The physical properties, such as density, reactivity, Young's modulus, and electrical and thermal conductivity, of an alloy may not differ greatly from those of its elements, but engineering or mechanical properties, such as tensile strength and shear strength may be substantially different from those of the constituent materials.
This is sometimes due to the sizes of the atoms in the alloy, since larger atoms exert a compressive force on neighboring atoms, and smaller atoms exert a tensile force on their neighbors, helping the alloy resist deformation. Alloys may exhibit marked differences in behavior even when small amounts of one element occur (Steel). Some alloys are made by melting and mixing two or more metals. Brass is an alloy made from copper and zinc. Bronze, used for statues, ornaments and church bells, is an alloy of tin and copper.

Unlike pure metals, most alloys do not have a single melting point. Instead, they have a melting range in which the material is a mixture of solid and liquid phases. The temperature at which melting begins is called the solidus and the temperature when melting is complete is called the liquidus. However, for most alloys there is a particular proportion of constituents which give them a single melting point or (rarely) two. This is called the alloy's eutectic mixture.

Phase diagrams (equlibrium diagrams). 

This page is an in-depth explanation of how a phase diagram is made (and what it really means).
http://www.chemguide.co.uk/physical/phaseeqia/snpb.html

Here is a (slightly) simplified equilibrium or phase diagram for Tin and Lead (Sn/Pb).

 

Assume we cool a liquid (molten) mixture containing about 67% lead and 33% tin by mass. This is what happens...

There are lots of things to look at:

  • Notice that nothing happens at all at the normal freezing point of the lead. Adding the tin to it lowers its freezing point.

  • Freezing starts for this mixture at about 250C. You would start to get some solid lead formed - but no tin. At that point the rate of cooling slows down - the curve gets less steep.

    However, the graph doesn't go horizontal yet. Although energy is being given off as the lead turns to a solid, there isn't anything similar happening to the tin. That means that there isn't enough energy released to keep the temperature constant.

  • The temperature does stop falling at 183C. Now both tin and lead are freezing. Once everything has solidified, the temperature continues to fall.


The special 62%Sn/38%Pb mixture cools like this...


This particular mixture of lead and tin has a cooling curve which looks exactly like that of a pure substance rather than a mixture. There is just the single horizontal part of the graph where everything is freezing. However, it is still a mixture. If you use a microscope to look at the solid formed after freezing, you can see the individual crystals of tin and lead.

 

http://www.benbest.com/cryonics/lessons.html

 

This particular mixture is known as a eutectic mixture. The word "eutectic" comes from Greek and means "easily melted".

The eutectic mixture has the lowest melting point (which is, of course, the same as the freezing point) of any mixture of lead and tin. The temperature at which the eutectic mixture freezes or melts is known as the eutectic temperature.

The real equilibrium (phase) diagram:


Notice that on both ends of the diagram there is a portion where the nearly pure metals have increasing melting points. Pure molten lead freezes at 327.5C into alpha structure. Pure molten Tin freezes at 232C into solid Beta Tin. So there are 3 things with sharp melting points, 100%PB, 100%Sn and 61.9%Sn/39.1%Pb.

Alloys are almost always stronger than the parent metals. Even with solder this is the case. Niotice that the Eutectic is the strongest alloy here.


Not all metals combine with any other for the full range from 0% to 100% to give a useful form of metal. (Eg Fe and Carbon is limited to a few % of C) Also, some binary alloys (2 metals) have multiple eutectics - like Magnesium/Tin. 



ALUMINIUM

Pure aluminium is soft, ductile, corrosion resistant and has a high electrical conductivity. It is widely used for foils, conductors for heat (e.g. radiator, cylinder head), and conductors for electricity (wire). For the best mechanical properties (strength etc) it is alloyed with other elements, such as copper, zinc, magnesium, silicon, manganese and lithium.
It takes a lot of electricity to smelt aluminium.
Read this link: (Including all 12 pages linked on the side)
http://sam.davyson.com/as/physics/aluminium/site/index.html


http://www.lme.co.uk/aluminium_industryusage.asp

Alloys

http://en.wikipedia.org/wiki/Aluminium_alloy
Wrought aluminium (rolled, extruded etc) is identified with a four digit number, followed the temper, e.g. 6061-T6, the most common free-machining aluminium alloy. Cast aluminium alloys use a four to five digit number with a decimal point. The digit in the hundred's place indicates the alloying elements, while the digit after the decimal point indicates the form (cast shape or ingot)

Wrought and Cast Aluminium Alloys

http://www.azom.com/details.asp?ArticleID=310
The main alloying elements are copper, zinc, magnesium, silicon, manganese and lithium. Small additions of chromium, titanium, zirconium, lead, bismuth and nickel are also made. Iron is invariably present in small quantities. There are over 300 wrought alloys with 50 in common use. They are normally identified by a four figure system which originated in the USA and is now universally accepted. 

Designations for alloyed wrought and cast aluminium alloys.

Major Alloying Element

Wrought

Cast

None (99%+ Aluminium)

1XXX

1XXX0

Copper

2XXX

2XXX0

Manganese

3XXX

 

Silicon

4XXX

4XXX0

Magnesium

5XXX

5XXX0

Magnesium + Silicon

6XXX

6XXX0

Zinc

7XXX

7XXX0

Lithium

8XXX

 

Unused

 

9XXX0

Some common aluminium alloys, their characteristics and common uses.

Alloy

Characteristics

Common Uses

Form

1050/1200

Good formability, weldability and corrosion resistance

Food and chemical industry.

S,P

2014A

Heat treatable. High strength. Non-weldable.
Poor corrosion reistance.

Mechanical components, airframes.

E,P

3103/3003

Non-heat treatable.
Medium strength work hardening alloy.
Good weldability, formability and corrosion resistance.

Vehicle panelling, structures exposed to marine atmospsheres, mine cages.

S,P,E

5251/5052

Non-heat treatable.
Medium strength work hardening alloy.
Good weldability, formability and corrosion resistance.

Vehicle panelling, structures exposed to marine atmospsheres, mine cages.

S,P

5454*

Non-heat treatable.
Used at temperatures from 65-200C.
Good weldability and corrosion resistance.

Pressure vessels and road tankers. Transport of ammonium nitrate, petroleum.
Chemical plants.

S,P

5083*/5182

Non-heat treatable.
Good weldability and corrosion resistance.
Very resistant to sea water, industrial atmospheres.
A superior alloy for cryogenic use (in annealed condition)

Pressure vessels and road transport applications below 65C.

Ship building structure in general.

S,P,E

6063*

Heat treatable. Medium strength alloy.
Good weldability and corrosion resistance.
Used for intricate profiles.

Architectural extrusions (internal and external), window frames, irrigation pipes.

E

6061*/6082*

Heat treatable. Medium strength alloy.
Good weldability and corrosion resistance.

Stressed structural members, bridges, cranes, roof trusses, beer barrels.

S,P,E

6005A

Heat treatable. Properties very similar to 6082.
Air quenchable, therefore has less distortion problems. Not notch sensitive.

Thin walled extrusions that risk  distortion.

E

7020

Heat treatable. Age hardens naturally therefore will recover properties in heat affected zone after welding.
Susceptible to stress corrosion.
Good ballistic deterrent properties.

Armoured vehicles, military bridges, motor cycle and bicycle frames.

P,E

7075

Heat treatable. Very high strength. Non-weldable.
Poor corrosion resistance.

Airframes.

E,P

Where: * = most commonly used alloys, S = sheet, P = plate and E = extrusions

Work Hardened Aluminium Alloys (Cold worked)

The 1000, 3000 and 5000 series alloys harden by cold work, usually by cold rolling. The mechanical properties will depend upon the degree of cold work and degree of annealing or stabilising thermal treatment afterwards. The standard numbering uses a letter, O, F or H followed by one or more numbers. 

Standard nomenclature for work hardened aluminium alloys.

New Symbol

Description

Old BS Symbol

O

Annealed, soft

O

F

As fabricated

M

H12

Strain-hardened, quarter hard

H2

H14

Strain-hardened, half hard

H4

H16

Strain-hardened, three quarter hard

H6

H18

Strain-hardened, fully hard

H8

H22

Strain-hardened, partially annealed quarter hard

H2

H24

Strain-hardened, partially annealed half hard

H4

H26

Strain-hardened, partially annealed three quarter hard

H6

H28

Strain-hardened, partially annealed fully hard

H8

H32

Strain-hardened and stabilised, quarter hard

H2

H34

Strain-hardened and stabilised, half hard

H4

H36

Strain-hardened and stabilised, three quarter hard

H6

H38

Strain-hardened and stabilised, fully hard

H8

Explanations of symbols used above.

Term

Description

Cold Work

The nomenclature denotes the degree of cold work imposed on the metal by using the letter H followed by numbers. The first number indicates how the temper is achieved.

H1x

Strain-hardened only to obtain the desired strength without supplementary thermal treatment.

H2x

Strain-hardened and partially annealed. These designations apply to products which are strain-hardened more than the desired final amount and then reduced in strength to the desired level by partial annealing. For alloys that age-soften at room temperature, the H2x tempers have the same minimum ultimate tensile strength as the corresponding H3x tempers. For other alloys, the H2x tempers have the same minimum ultimate tensile strength as the corresponding H1x tempers and slightly higher elongation.

H3x

Strain-hardened and stabilised. These designations apply to products which are strain-hardened and whose mechanical properties are stabilised either by a low temperature thermal treatment or as a result of heat introduced during fabrication. Stabilisation usually improves ductility. This designation is applicable only to those alloys which, unless stabilised , gradually age soften at room temperature.

H4x

H4x Strain-hardened and lacquered or painted. These designations apply to products which are strain-hardened and which may be subjected to some partial annealing during the thermal curing which follows the painting or lacquering operation.
The second number after H indicates the final degree of strain-hardening, number 8 being the hardest normally indicated.
The third digit after H, when used, indicates a variation of a two digit temper. It is used when the degree of control of temper or the mechanical properties or both differ from, but are close to, that (or those) for the two digit H temper designation to which it is added, or when some other characteristic is significantly affected.
The fully soft annealed condition is indicated by the letter O and the `as fabricated' ie material that has received no subsequent treatment is indicated as F.
To illustrate; it can be seen that 3103-0 denotes a particular aluminium manganese alloy in the annealed, soft condition, whilst 3103-H16 denotes the same alloy strain-hardened to three quarters hard.

For example, 3103-0 is an aluminium manganese alloy in the soft annealed condition and 3103-H16 is the same alloy three quarters hard.

With the flexibility of compositions, degree of cold work and variation of annealing and temperature a wide range of mechanical properties can be achieved especially in sheet products.

Solution Heat Treated and Age Hardened Aluminium Alloys

This is for 2000, 4000, 6000, 7000 and 8000 series alloys.  For aluminium, the heat treatment seems back-to-front compared to carbon steel (although there are some stainless steels that harden this way too). With these aluminium alloys, you quench to soften it, then keep it heated for some time to harden it!

Age hardening is also called precipitation hardening, because it causes a precipitate to form within the metal. It relies on changes in solid solubility with temperature to produce fine particles of an impurity phase, which impede the movement of dislocations (defects) in a crystal's lattice (which impedes slip - the cause of ductilty in metals). Unlike quenching for hardness, these alloys must be kept at elevated temperature for hours to allow precipitation to take place. This is called aging. For some alloys this happens by itself at room temperature, over a longer period (days,weeks).

Solution heat treating is where the alloy is heated to a suitable temperature and is held there long enough to allow a certain constituent to enter into solid solution. It is then quenched to hold that constituent in solution as a single phase. Solution heat treatments will soften or anneal. 

The wide choice of alloy compositions, solution heat treatment temperatures and times, quench rates from temperature, choice of artificial ageing treatment and degree to which the final product has been deformed permit a wide range of properties to be achieved. A system of standard designations is used, based upon the letter T followed a number after the alloy designation, to describe the various conditions. 

 Definition of heat treatment designations for aluminium and aluminium alloys.

Term

Description

T1

Cooled from an elevated temperature shaping process and naturally aged to a substantially stable condition.
This designation applies to products which are not cold worked after cooling from an elevated temperature shaping process, or in which the effect of cold work in flattening or straightening has no effect on mechanical properties

T2

Cooled from an elevated temperature shaping process, cold worked and naturally aged to a substantially stable condition. This designation applies to products which are cold worked to improve strength after cooling from an elevated temperature shaping process, or in which the effect of cold work in flattening or straightening does have an effect on mechanical properties.

T3

Solution heat-treated, cold worked and naturally aged to a substantially stable condition.
This designation applies to products which are cold worked to improve strength after solution heat-treatment, or in which the effect of cold work in flattening or straightening does have an effect on mechanical properties.

T4

Solution heat-treated and naturally aged to a substantially stable condition.
This designation applies to products which are not cold worked after solution heat-treatment, or in which the effect of cold work in flattening or straightening does not effect mechanical properties.

T5

Cooled from an elevated temperature shaping process and then artificially aged (i.e. heated).
This designation applies to products which are not cold worked after cooling from an elevated temperature shaping process, or in which the effect of cold work in flattening or straightening does not effect mechanical properties.

T6

Solution heat-treated and then artificially aged.
This designation applies to products which are not cold worked after solution heat-treatment, or in which the effect of cold work in flattening or straightening does not effect mechanical properties.

T7

T7 Solution heat-treated and overaged/stabilised
This designation applies to products which are artificially aged after solution heat-treatment to carry them beyond a point of maximum strength to provide control of some significant characteristic other than mechanical properties.

Aluminum is a lightweight, silvery white metallic element. Aluminum is the third most abundant element occurring in 8.3% of the earth's crust. It does not naturally occur in the metallic state. Metallic aluminum was first isolated in 1825 by Hans Christian Ørsted in Denmark. By 1888, the Aluminum Company of America (ALCOA) was producing large amounts of the inexpensive metal. Aluminum is a good electrical conductor and a good radiation reflector. The soft, nonmagnetic metal can be cast, extruded, rolled and wrought into many shapes. Metallic aluminum accepts a high polish and forms a thin, transparent, corrosion-resistant oxide layer. It can also be anodized, or electrolytically oxidized, to create a harder, more resistant oxide film.

Table 1: Alloying elements and their properties

Element Effect
Boron
  • grain refiner
  • improves conductivity by precipitating vanadium, titanium, chromium, and molybdenum.
Copper
  • Promotes solution heat treatment
  • increase strength and hardness
  • decrease elongation
  • increses resistance to stress-corrosion cracking
Lead
  • improves machinability
Manganese
  • high strength in the work-hardened condition
  • high resistance to corrosion
  • good welding characteristics
  • increases the tendency to crack during hot rolling
  • makes aluminum alloys easier to cast
Magnesium
  • increased strength without unduly decreasing ductility
  • corrosion resistance
  • good weldability
  • increased tendency to crack during hot rolling
Silicon
  • Precipitation upon age hardening
  • produces Mg2Si precipitates
  • mold release properties for die casting
Zinc
  • susceptibile to stress-corrosion cracking
  • Magnesium and zinc form MgZn2
Zirconium
  • form a fine intermetallic precipitate that inhibits recovery and recrystallization.
  • controls the grain structure in wrought products

Wrought Aluminum Alloy Classification

The term "wrought aluminum" refers to aluminum alloys that have been mechanically worked to improve the grain structure an physical properties. Wrought aluminum is in a form of sheet, foil, plate, rod, bar, or tubing and it leaves the mill in the "as formed" condition. This also includes forms such as extrusions, and some forgings. The transformation from ingot to wrought product gives the material its final stated properties. The forming operations, thermal treatments, and/or aging transform the cast ingot's metallurgic property and crystalline structure. This strongly influences the strength, corrosion resistance, and several other properties of the finished product.

Wrought Aluminum Numbering System

Aluminum classification numbering system has been established by American National Standards Institute (ANSI) and the Aluminum Association (AA). This classification system uses an alpha-numeric code to identify major alloying element and heat treating condition of the material. The primary alloy groups are designated by a four digit code. The first digit indicates the major alloying element as shown in the table below.

Table 2: Wrought Aluminum major alloying elements code

number alloy properties
1xxx Aluminum (99% minimum purity)
  • ductile
  • easily formed
  • corrosion resistant
2xxx Aluminum - Copper alloys
  • This is the most common heat treatable alloy.
  • aluminum-copper alloys respond to solution heat treatment
  • subsequent aging will increase strength and hardness while decreasing elongation.
3xxx Aluminum - Manganese alloys
  • Manganese increases strength either in solid solution or as a finely precipitated inter-metallic phase.
  • It has no adverse effect on corrosion resistance.
4xxx Aluminum - Silicon alloys
  • Most of aluminum-silicon wrought alloys are not heat-treatable (except alloy 4032 containing 1% of magnesium and alloy 4145 containing 4% of copper).
5xxx Aluminum - Magnesium alloys
  • Aluminum-magnesium alloys are not heat-treatable
  • may be strengthened by cold work (strain hardening)
  • Effectiveness of cold work hardening increases when magnesium content is increased.
  • Alloys of this series have moderate to high mechanical strength combined with relatively high ductility in annealed condition (up to 25%), good corrosion resistance and weldability.
6xxx Aluminum - Magnesium and Silicon alloys
  • Precipitation upon age hardening forms Guinier-Preston zones and a very fine precipitate.
  • Both of these increase the strength of these alloys
7xxx Aluminum - Zinc alloys
  • Aluminum-zinc alloys containing other elements offer the highest combination of tensile properties in wrought aluminum alloys.
8xxx Aluminum - Other Aluminum alloys
  • Aluminum-lithium alloys were developed for reducing weight in aircraft and aerospace structures.
  • Aluminum-lithium alloys are heat-treatable.
9xxx Aluminum - Unused

The second digit indicates modifications to the alloy formulation. When a new alloy is first introduced, the second digit is zero. Later if modifications to the chemical composition are made, a sequential number of 1 through 9 is used to designate the modified alloy. Within the 1xxx Aluminum group, a zero in the second digit indicates there is no special control on individual impurities. Digits other than zero indicate the number of impurities that are specifically controlled.

The last two digits are used as a commercial identifier for alloys within the group. Withing the 1xxx alloy group, the last two digits indicate specific minimum aluminum content. Although the absolute minimum aluminum content in this group is 99%, some grades have higher purity. The last two digits represent the hundredths of a per cent over 99%.

Experimental alloys are designated within the major groups of the four digit system, but are prefixed by the letter X. The prefix is dropped when the alloy becomes standard. During development, and before they are designated as experimental, new alloys are identified by serial numbers assigned by their originators. Use of the serial number is discontinued when the X number is assigned.

The four digit alloy designation also includes a suffix to indicate the type of heat treatment, temper, or type of straining process used to impart mechanical properties to the alloy. The two categories of suffix are for alloys that are heat treated to obtain physical properties and alloys that obtain physical properties by stain hardening, aging and tempering.

Non Heat-Treatable Alloy Suffix

Temper designations for heat treated wrought aluminum alloys consist of suffixes to the numeric alloy designations that begin with the letter "H" For example, in 3003-H14, 3003 denotes the alloy and “H14” denotes the temper, or degree of hardness. The temper designation also reveals the method by which the hardness was obtained. The letter "H" is always followed by 1, 2, or 3 digits. If there is only a single digit after the H it indicates hardness. If there are two digits, it indicates the method of hardening and the hardness.

Table 3: Wrought Aluminum alloy temper suffix code

first digit tempering method
xxxx-H1x strain hardened
xxxx-H2x strain hardened and partially annealed
xxxx-H3x strain hardened and stabilized
second digit degree of hardness
xxxx-Hx2 1/4 hardness
xxxx-Hx4 1/2 hardness
xxxx-Hx6 3/4 hardness
xxxx-Hx8 full hardness
xxxx-Hx9 extra hardness
third digit temper modification
xxxx-Hxx1 indcates stress relieved stretched

Heat-Treatable Alloy Suffix

Heat treatable aluminum alloy have a suffix of "F" to indicate the material properties were obtained as fabricated. This is common on extruded or forged shapes. If the product has been annealed the suffix is the letter "O" .  Certain members of the 7xxx group of alloys are solution heat treated and spontaneously age harden at room temperature.  This is important with heat treated rivets used in aircraft manufacture.  These items will have a "W" suffix that includes a time before age hardening occurs.  Finally, products that are specially processed to obtain physical properties have a suffix of "T" with numerals indicating the heat treating process and temper.  The letter “T” is always followed by one or more digits. These digits indicate the method used to produce the stable tempers.

Table 4: Heat treated aluminum alloy suffix codes

suffix heat treatment, temper and post process
xxxx-T3   Solution heat treated, then cold worked.
xxxx-T351 Solution heat treated, stress-relieved stretched, then cold worked.
xxxx-T36  Solution heat treated, then cold worked (controlled).
xxxx-T4   Solution heat treated, then naturally aged.
xxxx-T451 Solution heat treated, then stress relieved stretched.
xxxx-T5   Artificially aged only.
xxxx-T51  Solution heat treated, then stress relieved stretched, no straightnening
xxxx-T510 Solution heat treated, then stress relieved stretched, no straightnening
xxxx-T511 Solution heat treated, then stress relieved stretched, straightnened after stretching
xxxx-T6   Solution heat treated, then artificially aged.
xxxx-T61  Solution heat treated (boiling water quench), then artificially aged.
xxxx-T651 Solution heat treated, stress-relieved stretched, then artificially aged (precipitation heat treatment).
xxxx-T652 Solution heat treated, stress relieved by compression. then artificially aged.
xxxx-T7   Solution heat treated, then stabilized.
xxxx-T8   Solution heat treated, cold worked, then artificially aged.
xxxx-T81  Solution heat treated, cold worked (controlled), then artificially aged.
xxxx-T851 Solution heat treated, cold worked, stress-relieved stretched, then artificially aged.
xxxx-T9   Solution heat treated, artificially aged, then cold worked.
xxxx-T10  Artificially aged, then cold worked.

Common wrought aluminum alloys and properties

1100 This grade is pure aluminum. It is soft and ductile with good workability and can be polished to a mirror finish. It is ideal for applications involving intricate forming because it does not work harden as quickly as other alloys. This makes it ideal for foils and lithography plates. It is the most weldable of aluminum alloys, by any method. This grade can not be heat treated. It has excellent corrosion resistance and is widely used in the chemical and food processing industries and other uses where product purity is important. It responds well to embossed designs and finishes. Ductile enough for deep draws, but the lowest strength aluminum alloy. Uses include light reflectors, decorative and jewelry parts, name plates. Seldom used in precision sheet metal stampings.

2011 This is the most easily machined aluminum alloy. It also has excellent mechanical properties. Thus, it is widely used for automatic screw machine products and in parts requiring extensive machining.

2014 & 2017 These two alloys have excellent machinability and high strength 2014 has slightly higher tensile strength. It is a tough, ductile alloy suitable for heavy-duty structural parts and it's used in a wide variety of screw machined and billet parts.

2024 This is one of the most common high strength aluminum alloys. With its high strength and excellent fatigue resistance, it is used in applications where a high strength-to-weight ratio is desired. It is easily machined to a high finish. It can be forged or formed in the annealed condition, then heat treated for maximum strength and fatigue resistance. This alloy is not considered weldable, but may be spot, capacitive discharge, or seam welded. This alloy is usually anodized to provide corrosion protection or manufactured with a pure aluminum cladding (Alclad). This alloy is primarily used in aerospace industry for aircraft components, fittings, and hardware, Other uses include automotive wheels and other parts for the transportation industry.

3003 This is a general purpose manganese alloy that is the most widely used of all aluminum alloys. The addition of Manganese increases its' strength by 20% over the 1100 grade. This combines the excellent characteristics of 1100 with higher strength. It has excellent corrosion resistance. It has excellent workability and it may be deep drawn or spun. It can welded by all conventional processes. Like 1100, it also can not be heat treated. This alloy is commonly used to make cooking utensils, decorative trim, mail boxes, awnings, siding, storage tanks, and window frames lithography plates.

5005 This alloy is generally considered to be an improved version of 3003. It has the same general mechanical properties as 3003 but appears to stand up better in actual service. It is readily workable. It can be deep drawn or spun. It is weldable by all conventional processes. It has excellent corrosion resistance. It is non heat-treatable. It is well suited for anodizing and has less tendency to streak or discolor. It is used in many of the same applications as 3003.

5052 The main alloying element in this grade is magnesium. This makes it far stronger than any of the alloys described above, yet forms well with reasonable bend radii. This is the highest strength alloy of the more common non heat-treatable grades. Fatigue strength is higher than most aluminum alloys. In addition this grade has particularly good resistance to marine atmosphere and salt water corrosion. It has excellent workability. It may be drawn or formed into intricate shapes and its slightly greater strength in the annealed condition minimizes tearing that occurs in 1100 and 3003. Applications include a wide variety of home appliances, marine and transportation industry parts, heavy duty cooking utensils and equipment for bulk processing of food. Corrosion resistance and weldability are very good. It has better salt water corrosion resistance than 1100. 5052 is commonly used for electronic chassis, tanks, pressure vessels and any number of parts requiring considerable strength and formability at reasonable cost. Anodizing may be slightly yellowish.

5083 & 5086 For many years there has been a need for aluminum sheet and plate alloys that could be used for high strength welded applications. This alloy has several distinct benefits over such alloys as 5052 and 6061. Some of the benefits are greater design efficiency, better welding characteristics, good forming properties, excellent resistance to corrosion and the same economy as in other non heat-treatable alloys. Metallurgical researchers developed 5083 and 5086 as superior weldable alloys to fill these requirements. Both alloys have virtually the same characteristics with 5083 having slightly better mechanical properties due to higher manganese content. It is commonly used in unfired pressure vessels, missile propellant and oxidizer tanks, heavy-duty truck and trailer assemblies, boat hulls and superstructures.

6061 & 6063 This material is an alloy of magnesium and silicon. It is the most common material for extrusions and is the least expensive and most versatile of the heat-treatable aluminum alloys. It has most of the good qualities of aluminum. It offers a range of good mechanical properties and good corrosion resistance. It can be fabricated by most commonly used techniques. In the annealed condition it has good workability although it requires greater bend radii than 5052. In the T4 condition fairly severe forming operations may be accomplished. The full T6 properties may be obtained by artificial aging. It is welded by all methods and can be furnace brazed. It is available in the clad form (Alclad) for better appearance and corrosion protection. Applications include a wide variety of products from truck dump bodies and frames to screw machine parts and structural components and some marine applications.

6063 This grade is commonly referred to as the architectural alloy. It was developed as an extrusion alloy with relatively high tensile properties, excellent finishing characteristics and a high degree of resistance to corrosion. This alloy is most often found in various interior and exterior architectural applications, such as windows, doors, store fronts and assorted trim items. It is the alloy best suited for anodizing applications - either plain or in a variety of colors.

7075 This is one of the highest strength aluminum alloys available. Its strength-to weight ratio is excellent and it is ideally used for highly stressed parts. It may be formed in the annealed condition and subsequently heat treated. Spot or flash welding can be used, although arc and gas welding are not recommended. It is available in the clad (“Alclad”) form to improve the corrosion resistance with the over-all high strength being only moderately affected. Applications: Used where highest strength is needed.

7475 This is a superplastic-formable high-strength aluminum alloy, now available for structural applications and designated. Strength of alloy 7475 is in the range of aerospace alloy 7075, which requires conventional forming operations. Although initial cost of 7475 is higher, finished part cost is usually lower than that of 7075 because of the savings involved in the simplified design/assembly.

8090 is a class of aluminum-lithium alloys possess increased Modulus of Elasticity, high specific stiffness, increased fatigue strength and cryogenic strength. Alloys, containing silver, have also good weldability. Zirconium is added to aluminum-lithium alloys for controlling grain structureduring heat treatment. Aluminum-lithium alloys are used for manufacturing aircraft structures, aerospace vehicle skins, spacecraft fuel tanks (liquid Hydrogen and oxygen).

Cast Aluminum Alloy Classification

Aluminum can be ‘cast’ by every process used in metal casting. These processes, in descending order of quantity of aluminum casting are: die casting, permanent mold casting, sand casting, plaster casting, investment casting, and continuous casting. The casting process is selected based on factors such as cost, feasibility, quality of parts, etc. For instance, large products are made using sand casting. The quality factor is also important in selecting the casting process. Quality refers to both, mechanical properties (ductility and strength) and soundness (surface imperfections, cracking, and freedom from porosity).

The process of die casting utilizes almost two times the tonnage of aluminum alloys as the combination of other casting processes. Die casting is best suited for large quantity production of relatively small parts. Aluminum die castings up to 50 Kg can be produced if casting-machine costs and high tooling are justified.

Aluminum casting alloys are based on the same alloy system of thouse in the wrought categories.  They are strengthendby the same mechanisms, except strain hardening. and are similarly classified into hon heat treatbele and heat treatable type.s  The major difference is that the casing alloys usind in the geatest volumes contin allioying additions of silicon far in excess of the amounts in most wrought alloys.  Silicon is the allouning element that literally makes the commercial viability of the high volume aluminum cating industry possible. silicon contents from 4 to the eutectic level of 12 reduce scrap losses, permit production of more intricate designs with greater variations in section thickness and yield castings with highter surface and internal qualities.  These benefits are from the effects of silicon in icreasing fluidity, reducing cracking, and improving feeding to minimize shrinkage porosity

Die cast 380 aluminum has a higher tensile strength than gray cast iron yet only half the mass. There are a wide variety of aluminum alloys with various tensile strength, corrosion resistance, and heat treatments. Most easily cast alloys tend to be soft and have relatively low yield strength.  In the past, aluminum was mostly processed into form by the method of sand casting. Since the material cost was high, the cheapest available alloys were often used. It is some of these cheap cast alloys that have given this material an undeserved reputation. When aluminum is die cast, better alloys may be used that have remarkable characteristics. Small NEMA Motor endshields are die cast, 380 aluminum with a tensile strength of 48,000 psi. Compare this with soft gray cast iron that has 20,000 to 25,000 psi tensile strength.

The alloying system for aluminum uses a rational numbering system.  UNS and the Aluminum Association (AA) parallel each other in their numbering system.  For example, AA designates A356.0, UNS uses A13560. The AA numbering system is the most commonly used in the United States. It was adopted by AA in 1954 and approved by ANSI in 1957 (ANSI H35.1)  The American Society for Testing and Materials (ASTM), the Society of Automotive Engineers (SAE), and the Federal and Military specifications for aluminum castings conform to the AA designation system.

Cast Aluminum Numbering System

The first digit is an alpha indicator of base metal. Always A for aluminum in the UNS system.  The AA system uses the alpha character to distignuish between alloys that differ only slightly in percenages of impurities or minor alloying elements.  The alpha character can be A356.0, B356.0, F356.0 are common examples.

Table 5: Second Digit: Casting Alloy Designation

first
digit
primary element reason
Axxx.x Aluminum always the letter A to designate Aluminum
second
digit
alloy elements properties
A1xx.x 99% pure Aluminum  
A2xx.x Aluminum-Copper alloy capable of developing highest strengths among all castion alloys.  Good casting design and foundary techinques must be used to get full mechanical properties and consistent high quality parts.  Good high temperature strenght. Heat treatment is required with these allys.  Lower corrosion resistance and surface protection is required in critical applications
A3xx.x Aluminum-Silicon alloy with Copper and/or Magnesium low cost, highest volume usage.  Three main types Al-Si-Mg, Al-Si-Cu or Al-Si-Cu-Mg.  Those with copper are heat treatable. both copper and magnesium increase strenght and hardness in the as cast (f) temper and at elevated temperatures.  Arificial aging treatments
A4xx.x Aluminum-Silicon alloy based on the binary aluminum-silicons system and contain 5-12% SILICON.  mODERATE STRENGHT AND HIGH DUCTILITY IMPACR RESISTANCE
A5xx.x Aluminum-Magnesium alloy moderate to high strength and toughness.  High corrosion resistance especiall to sea water and marine atmospheres. can be welded and good machinability, anodized
A6xx.x unused  
A7xx.x Zinc  good finishing characteristics, good corrosion resistance. capable of high strenght through natural aging without heat treatment
A8xx.x Tin conatin 6%tin and small amounts of copper and nickel for strength.  These alloys were developed for bearing applications.  Tin imparts lubricity.
A9xx.x Other  
third&fourth
digits
alloy designation charactreristics
A319.x commercial code low cost Silicon-Copper alloy
A360.x   corrosion resistant
fifth
digits
specification type of specification
Axxx.0 casting casting specification
Axxx.1 ingot ingot specification
Axxx.2 ingot more tightly refined ingot specification

Some common casting alloys and their properties

A242 alloy is used extensively for applications where strength and hardness at high temperature are required. This alloy has good fluidity and shows resistance to hot cracking and shrinkage in the casting process. It has satisfactory weldability by arc and resistance methods but brazing is not recommended. Typical applications include: motorcycle, diesel, and aircraft engine pistons, aircraft generator housings, as well as air cooled cylinder heads.

A319 alloy exhibits good casting qualities including pressure tightness and moderate strength. It has good weldability and corrosion resistance. The casting and mechanical properties are not largely affected by fluctuations in impurity content. The main casting method for this alloy is sand casting. The uses include internal combustion and diesel engine crankcases. oil tanks and oil pans. It is also used in permanent mold casting with applications including water-cooled cylinder heads, rear axle housings and engine parts.

A355 an aluminum alloy with 0.02% copper added for greatly improved strength over the more common A356 material. This alloy yields highly consistent catings that are crack resistant, easy to repair, and have excellent tensile elongation properties. This has been used very effectively in aftermarket aluminum engine block castings. When heat treated to T6 condition the alloy remains very strong to 300° F which is 100° F higher than A356.

A356 aluminium alloys are characterized by very good mechanical properties and low porosity with a globular microstructure which is fine and uniform. The mechanical properties can be further improved through heat treatments such as T5 and T6. These alloys are used for casting general-purpose die castings. The common alloys used are 356-T6 for cast wheels. A356 has largely been replaced by 295 used in permanent mold castings for machine tool parts, aircraft wheels pump parts, tank car fittings, marine hardware, valve bodies, and bridge railing parts.

A360.0 is specified for die cast parts that require good corrosion resistance Special alloys for special applications are available, but their use usually entails significant cost premiums. This alloy is commonly found in applications such as frying pans, instrument cases, cover plates, and electronic component frames.

367.0 & 368.0 The Aluminum Association has designated two of these strontium containing Al-Si alloys developed by Mercury. 367.0 is used in all die cast L6 and L4 Verado drive shaft housings because 367.0 has nearly three times the impact energy of the typical die casting alloy. In addition, all swivel brackets that used to be made in A356-T6 are now made in 367-T6. Thus, the biggest and most critical parts, that must withstand two 40 miles per hour impacts on the gear case housing (also called the lower unit) without falling, have been converted to this alloy. 368.0 is used in all of Mercury's die cast boat propellers. The Al-Si alloy 368.0 replaced the single phase, Al-Mg 515 alloy that was used in boat propeller production for over 25 years because 368.0 had significantly higher strength and better ductility.

A380.0 is one of the most common general purpose die casting alloys. It has high tensile strength and is easily cast into intricate and large shapes. Components made from A380 have fair weldability, but brazing is not recommended. Generally, this alloy is machined with carbide tooling due to the abrasive silicon content of the alloy. Tools should be sharp with high rake and clearance angles.  Machines should be operated at moderate to high feeds and speeds to minimize tool wear. 380 provides the best combination of utility and cost. Some common applications of die cast parts using this alloy include lawn mower housings, streetlamps housings, dental equipment, air brake castings, gear cases and automatic transmission housings.

383 & 384 These alloys are a modification of 380. Both provide better die filling, but with a moderate sacrifice in mechanical properties, such as toughness.

A390 This alloy is hypereutectic aluminum-silicon alloy. The optimum structure of it must consist of fine, uniformly distributed primary Si crystals in a eutectic matrix. This alloy does not require heat treatment. The low coefficient of thermal expansion, high hardness and good wear resistance of these alloys make them suitable for internal comustion engines, pistons and cylinder blocks. A390 is often Selected for special applications where high strength, fluidity and wear-resistance/bearing properties are required.

413 Used for maximum pressure tightness and fluidity for complicated shapes in critical applications. A413.0 is commonly used for outboard parts of motor like connecting rods, pistons, housings.

514 This alloy has a relatively poor fluidity and a high degree of directional solidification shrinkage. High pressure die casting is the primary method of forming this alloy. This combination of material properties make 514 less casting friendly. As a result careful attention to casting geometry is essential. Because of its poor fluidity, fine detail and thin sections are difficult and radii must be large Because of shrinkage, feeding the casting requires large risers proper design. High ductility and excellent corrosion resistance is the main advantage of this alloy. It is commonly found boat propellers where impact toughness is required.

A518.1 for conveyor components, escalator parts, aircraft, marine hardware.

A535.0 is an aluminum-magnesium alloy with good combination of strength, shock resistance and ductility.  It is used for parts in instruments and tools where dimensional stability is a prime factor. This alloy doesn't require heat treatment. It is used in parts that need strength and stability like impellers, optical equipment. It can be polished and anodized. It has excellent machining properties and an exceptional finish can be produced, especially when machined with carbide tools at maximum speeds. It is highly resistant to corrosion and will not need any futher surace treatment for most applications. It is weldable in an inert gas or shieded arc methods.

A712 is employed when a combination of good mechanical proterties without heat treatment is needed.  It shows good shock and corrosion resistance.  Machinability and dimensional stability are also good.  No distortion is exhibited when A712.0 is heated.  After brazing the alloy wil regain its natural strenght by aging. it has fair to good castibiliity although pressure tightness and resistance to hot cracking are only fair.

713 This alloy.

Process considerations


Permanent Mold Casting Aluminum Alloys

Permanent mold casting is best suited for high-volume production. Their size is larger than die castings. These castings have a very low pouring rate. They are gravity-fed. Outstanding mechanical properties are exhibited by permanent mold castings. There is a lot of scope for further improvement if they are given heat treatment.

Some of the most common alloys of permanent mold casting include Alloy 366.0 for automotive pistons, Alloys 355.0, A357.0, C355.0 for impellers, timing gears, compressors, missile and aircraft components, Alloys A356.0, 356.0 for aircraft wheels, parts of pump parts, valve bodies, marine hardware, and 296.0, 333.0, 319.0.

Sand Casting Aluminum Alloys

This type of casting involves formation of casting mold (with sand). It is inclusive of conservative sand casting & lost-foam casting. The first one involves forming a pattern of sand, pouring the molten metal into it and breaking it once the product is formed. Lost-foam pattern involves putting a dispensable pattern of polystyrene in the mold. The rest of the procedure is the same as conservative sand casting.
 

Die Casting Aluminum Alloys

Aluminum die casting alloys  are lightweight, offer good corrosion resistance, ease of casting, good mechanical properties and dimensional stability.  Although a variety of aluminum alloys made from primary or recycled metal can be die cast, most designers select standard alloys such as A380

In high pressure die casting, which accounts for nearly 70% of all cast aluminum products made in the United States, it is the convention to use approximately 1% iron in the alloy to avoid die soldering. Actually depending on the alloy, the iron specification can be 1.2%  max, or 1.5% max, or even 2.0% max.  these levels of iron seriously degrade the mechanical properties. Thus, the task of obtaining superior die casting mechanical properties is to find other ways of avoiding die soldering without the use of iron. Substituting manganese for iron is a partial solution. A far better solution is with the use of high levels of strontium, in the range 500 to 700 ppm, which apparently either increases the surface tension of aluminum or forms a surface oxide, or both, and avoids die soldering.  tension of aluminum and creating "non-wetting" conditions.

The die castings of aluminum alloys are generally produced using aluminum -silicon-copper alloys. This alloy family gives an excellent combination of corrosion resistance, strength, and cost, along with respite from ‘hot shortness’ and high fluidity which are mandatory for easy casting. If one desires a better resistance to corrosion, he should make use of alloys having a lower copper content.

Physical properties of alloys using various process

Table 6: Sand Casting (F-Temper).

Alloy Grade 319 356 514 535 713
tensile strength (1000psi) 23.0 19.0 22.0 35.0 32.0
yield strength 13.0 --- 9.0 18.0 22.0
Major Alloying Elements - normal %          
silicon % 6.0 7.0 --- --- ---
copper % 3.5 --- --- --- ---
magnesium % --- 0.3 4.0 7.0 ---
zinc % --- --- --- --- 7.5
Characteristics (1 is best)          
corrosion resistance 3 2 1 1 3
machinability 3 3 1 1 1
polishing 2 2 3 4 4
weldability 2 2 3 4 4
cost 1 2 4 4 4

Table 7 more properties.

Tensile Strength Yield Strength Elongation Hardness
    psi psi % in 2" (500 kg load)
--- 319 27,000 18,000 2 70
--- 319-T6 36,000 24,000 2 80
--- A356 23,000 12,000 6 70
--- A356-T6 40,000 30,000 6 75
--- 357.0 25,000 13,000 5 -
--- 357-T7 46,000 36,000 3 85
--- 535 40,000 20,000 13 70
--- 705 30,000 17,000 5 -
--- 713 32,000 22,000 3 75

 




COPPER 

Copper is one of the few metals that can be found in nature as an uncompounded metal (called native copper - i.e. not as rusty or corrroded ore). Copper became popular around 2500 B.C., and it hasn't slowed...

Fig 1. Uses of Copper, 2005 (Data from Brook Hunt, 2005)

After iron and aluminium, copper is the third most commonly used metal. Most of the produced copper finds its way into electrical wire rod or copper tubes for plumbing.

Electrical Applications
The primary use of copper is for electrical applications. Copper is the best non-precious conductor of electricity (only silver is superior) and sets the standard to which other conductors are compared. Compared to copper, aluminium has worse conductivity per unit volume, but better conductivity per unit weight. Gold is sometimes used to plate fine wire applications not because it is a better conductor, but because it is extremely resistant to surface corrosion.
Copper is used in both insulated and non-insulated power cables for all regular voltage applications.

While optical fibre has displaced copper over long-haul applications, the telecom industry still demands copper, as it is still the preferred carrier for the last segment. Additionally, it is used for domestic carrier lines, wide and local area networks and connectors. HDSL (High-Speed Digital Subscriber Line) and ADSL (Asymmetrical Digital Subscriber Line) technology allows existing copper to carry high-speed data up to 1 giga-byte per second.

Copper is also starting to be used in the semiconductor industry instead of aluminium because it allows microprocessors to operate at higher speeds and reduces energy demand.

Construction Applications

Building construction accounts for more than 40% of all US copper consumption with residential construction accounting for two-thirds of that figure. The average 2,100 sq.ft. single-family home uses 439 pounds of copper, most of which is for wiring and plumbing.

Copper is still the preferred metal for plumbing applications because it suppresses the growth of the Legionella bacteria, the microbe responsible for Legionnaire's disease.

Transportation Applications

Today's average automobile contains between 50 to 60 pounds of copper. A Boeing 747-400 contains nearly 9,000 pounds, representing about 2% of the plane's total weight.
A typical diesel-electric railroad locomotive uses about 11,000 pounds of copper. The latest and most-powerful locomotives manufactured by General Electric Company and General Motors Corporation use more than 16,000 pounds.

Copper-nickel alloys are use for hulls of ships to reduce marine bio-fouling of mussels and barnacles.

Global Resources and Production

Known worldwide resource estimates for copper are estimated at 5.8 trillion pounds of which 0.7 trillion pounds (~12%) has been mined. Two-thirds of that is accessible on land and the remainder is available as deep-sea mineral rich nodules formed from undersea volcanic activity currently too expensive to retrieve.

Chile is the world's copper king in terms of reserves, production and refining capacity.

Copper's recycling rate is the highest out of any other engineering metal (around one-third of the US annual demand is recycled)

From http://dollardaze.org/blog/?post_id=00052&cat_id=20

ZINC

Current prices for zinc are hovering around its all time nominal high of US$2.082 per pound. From its 2003 low of $0.34 per pound, zinc has climbed nearly 500% to a $2.062 per pound close on Nov 24, 2006. Demand is high. 

Zinc's many different applications rank it as the 4th most commonly used metal behind iron, aluminium and copper.

Fig 2. Uses of Zinc for 2005 (Data from Brook Hunt, 2006)

The largest use of zinc is for the galvanization of steel. Nearly 60% of the world's annual consumption of over nine million tonnes is used to protect about 100 million tonnes of steel. The second largest use of zinc is as for making brass alloys.

The remaining zinc consumption is for making paint, chemicals, agricultural applications, household appliances and fittings, in the manufacture of electrical components, in the rubber industry, TV screens, fluorescent lights and for dry cell batteries.

Zinc Production

Global production of zinc has increased by 42% since 1995. China is the world's largest producer, consumer and refiner of zinc by a large margin. Canada and Australia are important exporters of zinc.The largest consumer of zinc, China, accounts for 30% of global demand. 

Zinc Plating: Zinc protects the steel by acting as a sacrificial anode - electrons being stripped from the zinc in preference to the steel. Hence, even if the zinc coating is scratched, it still protects the steel - unlike chrome plating that allows rust to penetrate underneath. Zinc anodes are used on boats by attaching a lump of zinc to the hull. Any process will work so long as the steel gets coated with zinc - so it depends how thick the zinc is. Parts usually need to be designed to allow the molten zinc to drain off the part quickly. See design info here: http://www.ingal.com.au/IGSM/12.htm

  • Hot-dip (approx 100m thick) by dipping in a molten bath of zinc at a temperature of around 435-460 C. It is left long enough for the zinc to chemically combine to the steel surface - "when it stops bubbling". Often see flakes (crystals or grains), initially bright finish that goes matt grey in a year or two. Expected life 50-100 years.  http://www.galvanizeit.org/
  • Electroplated zinc (about 1/10th the thickness of hot-dipped), shiny but very thin coating. Will not last long in wet/corrosive environment. 
  • Sherardizing: Zinc can also be applied to the surface by mechanical plating or sherardizing - coating steel with zinc by tumbling the article in powdered zinc at about 250-375C or up to 500C  giving a coating from 15-80m. http://www.sherardizing.com/
  • Zinc Spray Metallizing: Zinc is fired at high speed and coats the steel. Around 200m. Can be done on site.
  • Zinc Rich Paint is simply paint mixed with zinc dust. It must be thick enough and have high % of zinc in order to be conductive.

Cadmium plating is similar but toxic and losing favour.

Zinc Dangers: Zinc is considered toxic, but it is really only the fumes that can be dangerous - especially when welding. For galvanized structural fabrications, the zinc coating should be removed at least one to four inches from either side of the intended weld zone and on both sides of the piece.  Biologically, Zinc is one of the essential metals for life and plays a central role in the function of a number of proteins in living organisms - unlike the buildup of heavy metals such as lead, cadmium and mercury.

Zinc Alloys for Casting: Lowest temperature for common pressure casting metals.

 http://www.key-to-metals.com/Article21.htm




SILVER

Silver is both a precious metal and an important industrial metal. While nearly all of the 155,000 tonnes of gold that have ever been mined are still in the form of above-ground stocks, most of the silver has been consumed in industrial applications.

Silver used to serve a monetary role alongside gold. It was more applicable for everyday goods and services due and subsequently was widely used by the general population. Only government, banks and the wealthy dealt in gold coin.

Silver has many properties that make it useful as an industrial metal: high strength, malleable, ductile, highest thermal and electrical conductivity of any metal, sensitivity and high reflectance to light, chemical stability (does not corrode), ability to endure extreme temperature ranges.

Together, industrial, decorative and photography consume 95% of the annual silver supply.


Sterling silver (92.5% Ag, 7.5% Cu) is used in the manufacture of jewellery and silverware. The origin of the word "sterling" comes from the term "easterling" which referred to coins issued by the Hanseatic League, a group of trading cities in Northern Germany, which contained large proportions of silver. The British 'pound' originally had the value of one troy pound of sterling silver. It has since lost over 95% of its value.

Electrical Applications
Silver is the best electrical (and heat) conductor of all the metals and is used in conductors, switches, relays, circuit breakers, contacts and fuses. 

Printed circuits use silver paints, computer keyboards use silver electrical contacts, and silver is used in high voltage contacts because it can minimize arching due to carbon-polymer formation that occurs to other metals. 
In the home, wall switches, timing devices, thermostats, sump pumps, and virtually all electrical appliances use silver contacts. A typical washing machine requires 16 silver contacts to control its electric motor, pump, and gear clutch. A fully equipped automobile may have over 40 silver-tipped switches to start the engine, activate power steering, brakes, windows, mirrors, locks, and other electrical accessories.

Catalysts
An estimated 700 tons of silver are in continuous use as catalysts in the plastics industry. Silver is the only known catalyst for forming ethylene oxide (an intermediate chemical for polyester) from ethylene gas. It also serves as a catalyst in oxidation reactions such as the formation of formaldehyde (the building block of solid plastics) from methanol and air.

Light Reflection
Silver's unique optical reflectivity, and its property of being virtually 100% reflective after polishing, allows it to be used both in mirrors and in coatings for glass, cellophane or metals. Low quality mirrors use aluminium backing.
One out of every seven pairs of prescription eyeglasses sold in the U.S. incorporates silver. Silver halide crystals, melted into glass can change the light transmission from 96% to 22% in less than 60 seconds and block at least 97% of the sun's ultraviolet rays.

Photography
Silver nitrate made the first photograph in 1813 possible. Photosensitive chemicals silver chloride and silver bromide are prepared by adding sodium chloride or sodium bromide to a very pure solution of silver nitrate. While still a significant user of silver, film photography is in decline due to the advent of digital cameras

Soldering and Brazing
In 2005, 42.3 million ounces of silver were used for soldering and brazing. Silver is used as a superior solder than lead for air-conditioning and refrigeration equipment due to its greater ductility. Other uses include ceramic-to-ceramic joints and silicon chips to metallic surfaces.
Silver-based alloys used in brazing (above 600C) are suitable for nearly all steels and nonferrous metals except aluminium, magnesium, and titanium.

Other Uses
Superior power-to-weight batteries use silver oxides (both AgO and Ag2O) as the cathode silver-zinc primary and rechargeable batteries.Steel bearings are electroplated with high purity silver for greater fatigue strength, load-bearing capacity, and to significantly reduce friction.Silver is useful in dental alloys for fittings and fillings where it is alloyed with tin, copper and zinc.Many high-end musical instruments use silver for higher tone quality.

NICKEL

http://en.wikipedia.org/wiki/Nickel
http://www.nickelinstitute.org/index.cfm/ci_id/13.htm

Nickel is used in many industrial and consumer products, including stainless steel, magnets, coinage, and special alloys. It is also used for plating and as a green tint in glass. Nickel is pre-eminently an alloy metal, and its chief use is in the nickel steels and nickel cast irons, of which there are innumerable varieties. It is also widely used for many other alloys, such as nickel brasses and bronzes, and alloys with copper, chromium, aluminium, lead, cobalt, silver, and gold.

Nickel consumption can be summarized as: nickel steels (60%), nickel-copper alloys and nickel silver (14%), malleable nickel, nickel clad, Inconel and other Superalloys (9%), plating (6%), nickel cast irons (3%), heat and electric resistance alloys, such as Nichrome (3%), nickel brasses and bronzes (2%), others (3%).

In the laboratory, nickel is frequently used as a catalyst for hydrogenation, most often using Raney nickel, a finely divided form of the metal.

Nickel has also been often used in coins, or occasionally as a substitute for decorative silver. The American 'nickel' five-cent coin is 75% copper. The Canadian nickel minted at various periods between 1922-81 was 99.9% nickel, and was magnetic.

Nickel(III) oxide is used as the cathode in many rechargeable batteries, including nickel-cadmium, nickel-iron and nickel-metal hydride, and used by certain manufacturers in Li-ion batteries.

 

SuperAlloys
Rolls royce turbine blade: http://www.msm.cam.ac.uk/phase-trans/2003/Superalloys/coatings/index.html
These are high alloy steels for extreme high temperature, stress, corrosion environments like a jet engine turbine blade.


TIN

http://en.wikipedia.org/wiki/Tin
http://www.lme.co.uk/tin_industryusage.asp
Tin, like copper, was one of the first metals mined and its excellent qualities and shiny finish made it a highly sought after commodity. Particularly liked for its fusion abilities in the making of alloys, notably bronze, and its non-toxic qualities, tin was soon traded in many parts of the world.  Today it is still used in the production of bronze, pewter and die-casting alloys and, in modern engineering, to make tungsten more machineable. However, the largest uses for tin are for the production of solders and for tin plating (providing an attractive coating to iron and steel products).
Tin bonds readily to iron, and has been used for coating lead or zinc and steel to prevent corrosion. Tin-plated steel containers are widely used for food preservation, and this forms a large part of the market for metallic tin (as in"tins" or "tin cans").
Some important tin alloys are bronze, bell metal, Babbitt metal, die casting alloy, pewter, phosphor bronze, soft solder, and White metal.
The most important salt formed is stannous chloride, which has found use as a reducing agent and as a mordant in the calico printing process.
Electrically conductive coatings are produced when tin salts are sprayed onto glass. These coatings have been used in panel lighting and in the production of frost-free windshields.
Window glass is most often made via floating molten glass on top of molten tin (creating float glass) in order to make a flat surface (this is called the "Pilkington process").
Tin is also used in solders for joining pipes or electric circuits, in bearing alloys, in glass-making, and in a wide range of tin chemical applications. Although of higher melting point than a lead-tin alloy, the use of pure tin or tin alloyed with other metals in these applications is rapidly supplanting the use of the previously common lead–containing alloys in order to eliminate the problems of toxicity caused by lead.
Tin foil was once a common wrapping material for foods and drugs; replaced in the early 20th century by the use of aluminium foil, which is now commonly referred to as tin foil.
Industrial Tin consumption


Industry %
Solders 32
Tin Plate 27
Others 17
Alloys 14
PC Stabilisers 6
Tinning 4
Total 100


LEAD

http://en.wikipedia.org/wiki/Lead
solder: http://www.ami.ac.uk/courses/topics/0128_sm/index.html
lead overview: http://mysite.du.edu/~jcalvert/phys/lead.htm
lead-tin clickable phase diagram: http://www.sv.vt.edu/classes/MSE2094_NoteBook/CGImap/click5.html

Lead is very dense (heavy):
Lead is used as projectiles for firearms
Fishing sinkers
Lead or "sheet-lead" is used as a sound deadening layer in such areas as wall, floor and ceiling design in sound studios where levels of airborne and mechanically produced sound are targeted for reduction or virtual elimination.
Lead is used as shielding from radiation, e.g. in x-ray rooms.
Lead is used for the ballast keel of sailboats. Some metals are more dense but they are very expensive (Gold, Uranium)
Lead is frequently used in scuba diving weight belts to counteract the diver's natural buoyancy and that of his equipment.
Lead is often used to balance the wheels of a car; this use is being phased out in favor of other materials for environmental reasons.

Lead has low melting point:
Fishing sinkers and "backyard" casting
Pb/Sn solder alloys
Lead is still widely used in statues and sculptures.

Chemical uses of Lead
A coloring element in ceramic glazes, notably in the colors red and yellow.

Electrical uses of Lead
Lead is a major constituent of the lead-acid battery used extensively as a car battery.
Lead is used as electrodes in the process of electrolysis.
Lead is used in high voltage power cables as sheathing material to prevent water diffusion into insulation.
Lead is used in solder for electronics, although this usage is being phased out by some countries to reduce the amount of environmentally unfriendly waste.

Alloy uses of Lead
Lead is added to brass to reduce machine tool wear. Also in free cutting steel.

Lead is Ductile
Lead has many uses in the construction industry, e.g. lead sheets are used as architectural metals in roofing material, cladding, flashings, gutters and gutter joints, and on roof parapets. Detailed lead mouldings are used as decorative motifs used to fix lead sheet.

Lead is Toxic
Many lead containing products now banned/replaced. Leaded petrol, leaded paints etc. It is not nearly as dangerous as Mercury to handle.

Other Uses
Molten lead is used as a coolant, eg. for lead cooled fast reactors. 
Lead glass is composed of 12-28% lead oxide. It changes the optical characteristics of the glass and reduces the transmission of radiation.

Lead has been commonly used for thousands of years because it is widespread, easy to extract and easy to work with. It is highly malleable and ductile as well as easy to smelt. In the early Bronze Age, lead was used with antimony and arsenic. (Lovely mixture..!)  Lead is mentioned in the Book of Exodus (15:10).

Industrial Lead consumption


Industry %
Batteries 71
Pigments & other compounds 12
Rolled & extruded products 7
Shot / ammunition 6
Cable sheathing 3
Alloys 1
Total 100
http://www.lme.co.uk/lead_industryusage.asp

Titanium

Titanium looks slightly greyer than stainless steel, and has the best strength to weight ratio among the metals. Titanium is 40% lighter than steel and 60% heavier than aluminum.  Titanium is very reactive, and because of this it is often used for alloying and deoxidizing other metals. (more powerful deoxidizer of steel than silicon or manganese).  It also has excellent corrosion resistance, which stems from a thin oxide surface film which protects it from atmospheric and ocean conditions as well as a wide variety of chemicals. 
 
Fabrication   
Titanium is rather difficult to fabricate because of its susceptibility to oxygen, nitrogen, and hydrogen impurities which cause the titanium to become more brittle. Elevated temperature processing must be used under special conditions in order to avoid diffusion of these gasses into the titanium. Commercially produced titanium products are made in the following mill wrought forms; plate, tubing, sheet, wire, extrusions, and forgings. Titanium can also be cast, which must be done in a vacuum furnace because of titanium's reactive nature. (kaboom)
 
Applications 
Because of its high strength to weight ratio, titanium is used in a variety of applications, including products where weight is of importance such as aircraft, sporting equipment, etc.. Because of its excellent corrosion resistance, titanium is also used for chemical processing, desalination, power generation equipment, valve and pump parts, marine hardware, and prosthetic devices. 
 
Grades   
Commercially Pure Alloys: There are five grades of what is known as commercially pure or unalloyed titanium, ASTM Grades 1 through 4, and 7. Each grade has a different amount of impurity content, with Grade 1 being the most pure. Tensile strengths vary from 172 MPa for Grade 1 to 483 MPa for Grade 4. 
 
Alpha Alloys: Titanium alpha alloys are alloys that typically contain aluminum and tin, though they can also contain molybdenum, zirconium, nitrogen, vanadium, columbium, tantalum, and silicon. Alpha alloys do not generally respond to heat treatment, but they are weldable and are commonly used for cryogenic applications, airplane parts, and chemical processing equipment. 
 
Alpha-Beta Alloys: Alpha-beta alloys can be strengthened by heat treatment and aging, and therefore can undergo manufacturing while the material is still ductile, then undergo heat treatment to strengthen the material, which is a big advantage. The alloys are used in aircraft and aircraft turbine parts, chemical processing equipment, marine hardware, and prosthetic devices. 
 
Beta Alloys: The smallest group of titanium alloys, beta alloys have good hardenability, good cold formability when they are solution-treated, and high strength when they are aged. Beta alloys are slightly more dense than other titanium alloys, having densities ranging from 4840 to 5060 kg/m3. They are the least creep resistant alloys, they are weldable, and can have yield strengths up to 1345 MPa. They are used for heavier duty purposes on aircraft. 
 


Magnesium

Magnesium is a silvery-white metal that is principally used as an alloy element for aluminum, lead, zinc, and other nonferrous alloys. Magnesium is among the lightest of all the metals, and also the sixth most abundant on earth. Magnesium is ductile and the most machinable of all the metals. Magnesium has a protective film to protect against corrosion, however it is easily corroded by chlorides, sulfates, and other chemicals, therefore magnesium is often anodized to improve its corrosion resistance. 
 
Applications   
Due to its light weight, superior machinability and ease of casting, magnesium is used for many purposes such as auto parts, power tools, sporting goods, aerospace equipment, fixtures, and material handling equipment. Automotive applications include gearboxes, valve covers, wheels, clutch housings, and brake pedal brackets. Wrought alloys are available in rod, bar, sheet, plate, forgings, and extrusions. 
 


Whiteboard


 

DVDs

1. Metals [videorecording] Romay, Juan.

[Bilbao, Spain?] : Near, S.A., c2005. Publisher: DIDAVISION. 1 videodisc (20 min.) : sd., col., 4 3/4 in.

History of metals, common metals, heavy metals, iron, aluminium. Basic overview but not a lot of useful engineering information.

DVD 669/ROMA

 

2. The making of aluminium [videorecording] Advanced version. Russell, Geoff.

1993. Video Education Australia. DVD (30 min.)

Explains the process of smelting aluminium using the smelter at Portland smelter in Victoria as an example.

Detailed analysis of refining and smelting of aluminium. Covers production, economic, environmental issues. Excellent quality.

DVD 669.722/RUSS

 

 

 

 

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