1. Lecture 16 – Copper and its alloys
Prescribed Text:
Ref 1: Higgins RA & Bolton, Materials for Engineers and Technicians, 5th edition, Butterworth Heinemann. ISBN:
Readings:
Callister: Callister, W. Jr. and Rethwisch, D., 2010, Materials Science and Engineering: An Introduction, 8th Edition, Wiley, New York. ISBN
Ashby 1: Ashby, M. & Jones, D., 2011, Engineering Materials 1: An Introduction to Properties, Applications and Design, 4th edition, Butterworth-Heinemann, Oxford UK. IBSN:
Ashby 2: Ashby, M. & Jones, D., 2011, Engineering Materials 2: An Introduction to Microstructures and Processing, 4th edition, Butterworth-Heinemann, Oxford UK. IBSN:
Lecture (2 hrs):
Ref 1, Ch 1: Engineering materials;
Ref 1 Ch 2: Properties of materials.
Laboratory 1 (2 hrs): Hardness test
Callister: Ch 1, 2, 18-21
Ashby 1: Ch 1, 2
Ashby 2: Ch 1 1

2. Copper and its alloys Reference Text Section
Higgins RA & Bolton, Materials for Engineers and Technicians, 5th ed, Butterworth Heinemann
Ch 16
Additional Readings
Section
Engineering Materials and Processes

3. Note: This lecture closely follows text (Higgins Ch16)
Copper and its alloys
Note: This lecture closely follows text (Higgins Ch16)
Engineering Materials and Processes

4. Copper (Higgins 16.1) READ HIGGINS 16.1 Some history…
And for a bit more up-to-date action…
Bronze-age weaponry
Engineering Materials and Processes

5. Uses of copper Engineering Materials and Processes
Engineering Materials and Processes

6. Worldwide Copper Production
Worldwide Copper Production may be nearing its peak.
Copper is closely linked to demands of industrial expansion– needed for both infrastructure and electrical products.
Engineering Materials and Processes

7. Copper Price
The price of copper is sensitive to production demands (set by manufacturing outlook: i.e. companies placing orders based on their projected production)
It is also magnified by tightening supply as China and India increase demand.
So copper price rises on optimism.
Note the GFC drop.
Engineering Materials and Processes

8. The extraction copper (Higgins 16.2)
READ HIGGINS 16.2
The extraction of copper
The 2010 Copiapó mining accident in Chile’s San José copper–gold mine. The 33 miners were trapped 700m underground, surviving for a record 69 days before their rescue through drilled holes.
Extraction of copper
Wikipedia
Engineering Materials and Processes

9. Properties of copper (Higgins 16.3)
READ HIGGINS 16.3
Conductivity (electrical and thermal)
Corrosion resistance
Ductility
Engineering Materials and Processes

10. Coppers and alloys (Higgins 16.4)
READ HIGGINS 16.4
Oxygen-free high-conductivity (OFHC) copper: Electrolytically refined: Electrical uses
'Tough-pitch' copper: Heat refined. Lower conductivity.
Deoxidised copper: Tough pitch copper deoxidised with phosphorus which improves weldability, but worse electrically.
The Xstrata copper electrorefining tankhouse at Copper Refineries in Townsville, Queensland, Australia.
Engineering Materials and Processes

11. Coppers and alloys (Higgins 16.4)
READ HIGGINS : Alloys of copper
1. Brasses: copper-zinc alloys
2. Bronzes: copper-tin alloys
Phosphor bronzes: copper-tin-phosphorus alloys
Gunmetals: copper-tin-zinc alloys
3. Aluminium bronzes: copper-aluminium alloys
4. Cupro-nickels: copper-nickel alloys
Nickel silvers: copper-zinc-nickel alloys
5. Beryllium bronzes: copper-beryllium alloys
Engineering Materials and Processes

12. The brasses (Higgins 16.5) READ HIGGINS 16.5: CAREFULLY!
Brass: Up to 45% Zn, also some Sn, Pb, Al, Mn, Fe
Figure 16.1 The section of the copper-zinc equilibrium diagram which covers brasses of engineering importance. (Higgins)
Engineering Materials and Processes

13. The brasses (Higgins 16.5) Complete copper-zinc equilibrium diagram:
Phases:
a up to 37% Zn: Ductile: e.g. 70/30
Cold working
b above to 37% Zn
Hot working
Tin: corrosion
Lead: machinablilty
Engineering Materials and Processes

14. The brasses (Higgins 16.5) READ HIGGINS 16.5: CAREFULLY!
70/30 Brass: That’s copper/zinc ratio
(i) brass as cast with cored crystals of a solid solution
(ii) brass, cold worked and then annealed at 600°C. The coring of the original cast structure has been removed by this treatment and recrystallisation has produced small crystals (twinned) of the solid solution a
(Higgins Fig 16.2)
Engineering Materials and Processes

15. The brasses (Higgins 16.5) READ HIGGINS 16.5: CAREFULLY!
Brass: Up to 45% Zn, also some Sn, Pb, Al, Mn, Fe
(iii) brass as cast. This shows a typical Widmanstdtten structure and, on cooling, small a crystals (light) have precipitated from the b phase (dark).
(Higgins Fig 16.2)
Engineering Materials and Processes

16. Engineering Materials and Processes
Higgins
Engineering Materials and Processes

17. Engineering Materials and Processes
Higgins
Engineering Materials and Processes

18. The brasses (Higgins 16.5) READ HIGGINS 16.5.1 'Shape memory' alloys
'Shape memory' alloys have two distinct crystal structures that revert at a critical transformation temperature. Below the CTT structure is like martensite, and reverts back when heated above CTT.
The shape change can be used to operate temperature-sensitive devices: automatic greenhouse ventilators, thermostatic radiator valves, de-icing switches, electric kettle switches and valves in solar heating systems.
Note:
The most widely used shape memory alloy is the equi-atomic Nickel Titanium alloy known commercially as Nitinol.
Engineering Materials and Processes

19. Tin bronzes (Higgins 16.6) READ HIGGINS 16.6
Tin bronzes, contain up to 18% Sn (Tin) with smaller amounts of P, Zn, Pb
1. Wrought tin bronzes up to 7% tin. Sheet, wire, drawn rod.
2 Cast tin bronzes with 10 to 18 % tin, used mainly for bearings.
Engineering Materials and Processes

20. Bronzes (Higgins 16.6)
Engineering Materials and Processes

21. Bronzes (Higgins 16.6)
Engineering Materials and Processes

22. Aluminium bronzes (Higgins 16.7)
READ HIGGINS 16.7
Two groups: cold-working alloys, and the hot-working alloys.
1. Wrought tin bronzes up to 7% tin. Sheet, wire, drawn rod.
2 Cast tin bronzes with 10 to 18 % tin, used mainly for bearings.
33 tonne propellor made from nickel aluminum bronze.
qe-carrier.blogspot.com
Engineering Materials and Processes

23. Aluminium bronzes (Higgins 16.7)
Engineering Materials and Processes

24. Copper-nickel alloys (Higgins 16.8)
READ HIGGINS 16.8
Cu and Ni complete solubility. Corrosion resistant.
Nickel-silvers
Engineering Materials and Processes

25. Engineering Materials and Processes

26. Other copper alloys (Higgins 16.9)
READ HIGGINS 16.9
Beryllium bronze
Non-sparking tools
Copper-chromium
Conductive & strong.
Copper-cadmium
Drawn electrical wire
Copper-tellurium
Machined electrical
Arsenical copper
Thermal
Engineering Materials and Processes

27. Online Resources. Cast Iron Extraction of copper
Extraction of copper
h ttp://
S how this website on screen. Will be using this later.
Engineering Materials and Processes 27

28. Engineering Materials and Processes
GLOSSARY
Brass
Bronze
Electrolysis
Phosphor bronzes
Gunmetals
Aluminium bronzes
Cupro-nickels
Nickel silvers
Beryllium bronzes
Engineering Materials and Processes 28

29. Define all the glossary terms.
QUESTIONS
Moodle XML: Some questions in Steel
Define all the glossary terms.
Describe the name, uses and properties of 70/30 brass.
What constituents determine the names brass and bronze?
Describe how electrical grade copper is made.
Explain why applications that used copper alloys (e.g. cartridge brass) are being replaced with aluminium and mild steel.
Using current prices from LME (London Metals Exchange), determine the cost of ingredients for 1 tonne of High-tin bronze – Higgins Table 16.2.
Describe the following copper-based alloys and their uses. Monel, gunmetal, gilding metal, cartridge brass, free-cutting brass
What ingredient is added to brasses and bronzes to improve machability. Describe how this works in reference to microstructure.
Silver is the most conductive metal. By comparison, copper is 97%, gold 71% and aluminium 58%. Using current prices of each metal, rank conductivity per dollar.
Research the advantages and disadvantages of using aluminium vs copper for use as electrical conductors. Why is strength and conductivity difficult?
Engineering Materials and Processes 29