Non-Ferrous Alloys Lecture Notes

Flashcards using vocabulary style

Non-ferrous metals

Metals not based on iron (Fe)

Examples of Non-ferrous metals

Cu, Zn, Sn, Ni, Al, Mg, Ti, Pb

Key features of Aluminum

Low density (1/3rd of steel), low strength but excellent specific strength, recycling uses 5% of production energy, high purity gives corrosion resistance, High purity: 30-50 % elongation, high electrical conductivity, formable

Applications of Non heat-treatable wrought alloys

Aircraft frames, aircraft skin (Boeing 737: 80% Al), train coaches, boats & canoes

Applications of Cast Aluminum alloys

General castings, electrical motor casings, combustion engine blocks, marine components

Precipitation / age hardening

Heat treatment to form second phase precipitates, particularly relevant to high strength Al

Effects of Precipitation / age hardening

Increased strength, Decreased ductility

Alloying elements for Strengthening Aluminum alloys

Mg, Mn, Zn, Cu

Alloying elements for Corrosion resistance in Aluminum alloys

Mg, Si

Alloying elements for Lower melting point, low thermal expansion coefficient in Aluminum alloys

Si

Alloying elements for Hardness in Aluminum alloys

Sn

Key features of Magnesium

Very low density! (1.74 g/cm3 – well-matched to bone density), some ductility (less so than aluminium), lower melting point than aluminium, not as strong as aluminium (but still high specific strength), low Young’s modulus (45 GPa), poor resistance to fatigue, wear & creep

Magnesium Alloying elements

Fe, Si, Cu: low solubility in Mg and reduce corrosion resistance; Zr: reduces effect of above elements; Y, Nd, Dy: promote protective oxide coating; Zn: hardening; Th, Ag: improve strength and reduce creep

Magnesium alloys - applications

Front End Structures, Transfer Case, Engine Cradle, Instrumental Panel, Steering Column Brackets, Transmission Case, Cam Covers, Seat Back/Seat Cushions, Laptop cases, Steering wheels cores, Center Console, 3rd Row Seat Frames, Header Bow, Biomedical implants

Key features of Copper

Higher density than steel (8.96 g/cm3), high yield strength (30-400 MPa) but low specific strength, excellent ductility – good for forming tubing, excellent electrical and thermal conductivity

Copper: Copper alloys – applications

Aerospace applications, electrical wire, plumbing components, High conductivity cookware

Monel (Ni-Cu)

High strength (> 1 GPa), high elongation (30s %), corrosion resistance, high temperature performance

Nichrome (Ni-Cr)

High temp oxidation resistance (heating elements)

Nickel superalloys

Long-term operation at 1100°C under tensile loads in oxidising environments

Nickel - applications

Plating, Gas turbines, Heating elements

Key features of Titanium

Very high strength (can be almost 1.4 GPa!), low density (4.505 g/cm3) so enormous specific strength, low Young’s modulus (116 GPa), excellent corrosion resistance (to 535°C) – forms oxide layer

Titanium alloys – controlling the phases

Heat treatment then controls microstructure & properties, strength and ductility

Titanium - applications

Dental implant, Heart valve cage, Knee joint, Cranial plate, Stent, Pacemaker, Gas turbines, Aerospace engines, Hip joint, Implants