Lecture 16 – Copper and its alloys Prescribed Text: Ref 1: Higgins RA & Bolton, 2010. Materials for Engineers and Technicians, 5th edition, Butterworth Heinemann. ISBN: 9781856177696 Readings: Callister: Callister, W. Jr. and Rethwisch, D., 2010, Materials Science and Engineering: An Introduction, 8th Edition, Wiley, New York. ISBN 9780470419977 Ashby 1: Ashby, M. & Jones, D., 2011, Engineering Materials 1: An Introduction to Properties, Applications and Design, 4th edition, Butterworth-Heinemann, Oxford UK. IBSN: 9780080966656 Ashby 2: Ashby, M. & Jones, D., 2011, Engineering Materials 2: An Introduction to Microstructures and Processing, 4th edition, Butterworth-Heinemann, Oxford UK. IBSN: 9780080966687   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

Copper and its alloys Reference Text Section Higgins RA & Bolton, 2010. Materials for Engineers and Technicians, 5th ed, Butterworth Heinemann Ch 16 Additional Readings Section Engineering Materials and Processes

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

Copper (Higgins 16.1) READ HIGGINS 16.1 Some history… And for a bit more up-to-date action… Bronze-age weaponry http://en.wikipedia.org/wiki/File:Bronze_age_weapons_Romania.jpg Engineering Materials and Processes

Uses of copper Engineering Materials and Processes http://www.inmetmining.com Engineering Materials and Processes

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

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. http://www.kitcometals.com Engineering Materials and Processes

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

Properties of copper (Higgins 16.3) READ HIGGINS 16.3 Conductivity (electrical and thermal) Corrosion resistance Ductility http://www.sciencelearn.org.nz http://www.reuters.com Engineering Materials and Processes

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

Coppers and alloys (Higgins 16.4) READ HIGGINS 16.4.1: 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

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

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 http://pwatlas.mt.umist.ac.uk Engineering Materials and Processes

The brasses (Higgins 16.5) READ HIGGINS 16.5: CAREFULLY! 70/30 Brass: That’s copper/zinc ratio (i) 70-30 brass as cast with cored crystals of a solid solution (ii) 70-30 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

The brasses (Higgins 16.5) READ HIGGINS 16.5: CAREFULLY! Brass: Up to 45% Zn, also some Sn, Pb, Al, Mn, Fe (iii) 60-40 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

Engineering Materials and Processes Higgins Engineering Materials and Processes

Engineering Materials and Processes Higgins Engineering Materials and Processes

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. http://www.doitpoms.ac.uk/tlplib/superelasticity/uses.php Engineering Materials and Processes

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

Bronzes (Higgins 16.6) Engineering Materials and Processes

Bronzes (Higgins 16.6) Engineering Materials and Processes

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

Aluminium bronzes (Higgins 16.7) Engineering Materials and Processes

Copper-nickel alloys (Higgins 16.8) READ HIGGINS 16.8 Cu and Ni complete solubility. Corrosion resistant. 16.8.1 Nickel-silvers Engineering Materials and Processes

Engineering Materials and Processes

Other copper alloys (Higgins 16.9) READ HIGGINS 16.9 16.9.1 Beryllium bronze Non-sparking tools 16.9.2 Copper-chromium Conductive & strong. 16.9.3 Copper-cadmium Drawn electrical wire 16.9.4 Copper-tellurium Machined electrical 16.9.5 Arsenical copper Thermal Engineering Materials and Processes

Online Resources. Cast Iron Extraction of copper http://www.msm.cam.ac.uk/phase-trans/2001/adi/cast.iron.html Extraction of copper h ttp://www.matweb.com S how this website on screen. Will be using this later. Engineering Materials and Processes 27

Engineering Materials and Processes GLOSSARY Brass Bronze Electrolysis Phosphor bronzes Gunmetals Aluminium bronzes Cupro-nickels Nickel silvers Beryllium bronzes http://www.youtube.com/watch?v=1GFst2IQBEM Engineering Materials and Processes 28

Define all the glossary terms. QUESTIONS Moodle XML: Some questions in 10105 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? http://www.youtube.com/watch?v=1GFst2IQBEM Engineering Materials and Processes 29