1. Aluminium (Al) Extremely useful engineering material o has low density (2.70 g/cm3) o good corrosion resistance in most natural environment o non-toxic : suitable for food containers and packaging o good electrical and thermal properties o low strength : can be alloyed o can be divided into 2 groups 1. Non-heat treatable alloys 2. Heat treatable alloys
Non-Heat Treatable Al Alloys Cannot be strengthened (precipitation hardening) Strength can be increased only through cold-work Three main groups : 1xxx, 3xxx and 5xxx series Heat Treatable Al Alloys Can be strengthened (precipitation hardening) Three main groups : 2xxx, 6xxx and 7xxx series
Non-Heat Treatable Al Alloys Condition stensile Al Assoc. No. Wt% Application 1100 0.12Cu Annealed 90 Heat exchangers Sheet metal 3003 0.12Cu, 1.2Mn, 0.1Zn Annealed 110 Pressure vessels Chemical equipment 5052 2.5Mg, 0.25Cr Strain Hardened 230 Bus, truck, marine uses Hydraulic tubes (Mpa)
Heat Treatable Al Alloys Condition stensile Al Assoc. No. Wt% Application 2024 4.4Cu, 1.5Mg, 0.6Mn Heat treated (T6) 470 6061 1.0Mg, 0.6Si, 0.3Cu, 0.2Cr Heat treated (T6) 240 Trucks, marine structures, bicycle frames 7075 5.6Zn, 2.5Mg, 1.6Cu, 0.23Cr Heat treated (T6) 570 Aircraft structural parts (Mpa) Aircraft structures
Cast, Heat-treatable Alloys Condition stensile Al Assoc. No. Wt% Application 295.0 4.5Cu, 1.1 Si Heat treated 221 Aircraft wheels 356.0 7.0Si, 0.3Mg Heat treated 228 Automotive transmission cases (Mpa)
295.0 356.0
Aluminium-Lithium Alloys New generation of Al alloys Low density, high specific modulus Excellent fatigue properties Excellent low-temperature toughness properties Al Assoc. No. Wt% Condition stensile Application 2090 2.7Cu, 0.25Mg, 2.25Li, 0.12Zr Heat treated, cold worked 455 Aircraft structures 8090 1.3Cu, 0.95Mg, 2.0Li, 0.1Zr Heat treated, cold worked 465 Aircraft structures
2. Copper (Cu) In pure form : high electrical and thermal conductivity good corrosion resistance ease of fabrication medium tensile strength general soldering and joining characteristics high strength can be achieved by alloying eg: brass and bronze Copper Brass Bronze
Copper-Zinc Alloys (Brass) Zn predominant alloy (5 40%). Relatively soft, ductile and easily cold worked. Higher Zn is harder and stronger. Exp: 1) α Brass (Catridge Brass) C26000 ~ 70% Cu 30% Zn (Single phase - ) ~ Applications : radiators, lamp fixtures, fasteners, locks, hinges, bullet casing 2) Muntz metal - C28000 ~ 60% Cu 40% Zn (Two phases + ) ~ Applications : architechtural, large nuts and bolts, condenser tubing
α Brass (Catridge Brass) Muntz metal
Copper-Tin Alloys (Bronze) Copper alloyed with 1 10% tin (Sn) to form solid solution Often called phosphor bronze Stronger than brass esp. in cold worked conditions, better corrosion resistance Applications : valves, pipe fittings, pump castings, water pump impellers and housing
Copper- Beryllium Alloys Containing 0.6 2.0% Be and 0.2 2.5% Co Can be precipitation hardened, heat treated and cold worked increases tensile strength to 1463 Mpa Highest strength copper alloys Excellent corrosion resistance, fatigue properties and strength Applications : jet aircraft landing gear bearings and bushings, springs, surgical & dental instruments.
Alloy name Wt% Condition stensile Application (Mpa) Electrolytic tough pitch 0.04O Annealed 220 Electrical wire Beryllium Copper 1.9Be, 0.2Co Precipitation hardened 1300 Springs Cartridge Brass 30Zn Annealed Cold-worked 300 525 Automotive radiator cores Phosphor Bronze 5Sn, 0.2P Annealed Cold-worked 325 560 Clutch disks
3. Titanium (Ti) New, possess extraordinary combination of properties. Low density (4.5g/cm3), high melting point (1668OC), high E (107GPa). Major limitation is its chemical reactivity with other materials at elevated temperature expensive. Unusually high corrosion resistance air, marine, industrial environments. Used in airplane structures, space vehicles, surgical implants, petroleum & chemical industries.
Alloy type Wt% Condition stensile Application (Mpa) Commercially pure 99.1Ti (Unalloyed) Annealed 484 Airframe skins a 5Al, 2.5Sn Annealed 826 Gas turbine engine casings Near a 8Al, 1Mo, 1V Annealed 950 Jet engine components (compressor)
Alloy type Wt% Condition stensile Application (Mpa) a-b 6Al, 4V Annealed 947 Prosthetic implants a-b 6Al, 2Sn, 6V, 0.75Cu Annealed 1050 Rocket engine airframe b 10V, 2Fe,3Al Solution + Aging 1223 High strength airframe components
4. Nickel (Ni) Exceptional resistance to corrosion and high temperature oxidation FCC structure highly formable High density (8.9 g/cm3) Pure Ni Good strength and electrical conductivity electrical and electronic parts Good corrosion resistance food processing equipment Monel Alloys Solid solution of Cu (30%) in Ni. Can be age-hardened High strength Applications : Chemical, food and oil processing, valves, pumps, springs