Question

Q2-B Using figure Q 2-A (the above), sketch neatly the microstructure of the alloys (indicate the amount of each phase presented) given in table Q 2-B (assumed it is cooling at equilibrium) [80 Marks] Answer of O 2-B Table Q2-B Structure of the alloys Compositions Temperature Structure Compositions Temperature Structure 32.5% Cu 10% Cu Room Room temperature temperature I 2% Cu 550 C 40% Cu Room temperature Q2-A Figure Q2-A shows the equilibrium phase diagram of aluminium and copper metals at different compositions and temperatures. Show on the diagram the followings 1. the temperature at which the microstructure of the alloy starts forming 75 pph eutectic. 2 the temperature in which dendrites start forming for the 20 % Cu alloy. 3. the range of Cu % (copper percentage) in which the alloy consists of 30 pph Al and 70 pph cutectic (AI+CuAl) at room temperature 4 the Cu % in which the alloy contains 100 pph compound CuAlk at room temperature the range of temperature in which the alloy is 100 pph Al when 5% Cu is added to the AL 5. 30 Marks Answer of O 2-A 800 Liquid 700 600 A L L+CuAI 500 Compound CuAl AHrich solid (Al 400 (Aly CuAl 300 200 100 50 10 30 40 60 70 20 Al wt % Cu Figure O2 Aquilibrun phas diagran of Alunauum alloy wah copper OUESTION 2 (Continued) Temperature, T (C)

Answer 1

Answent Griven fiqure shows the Eaxi bibrium phas diamam of alunaini tempena ture and Copper metals anol Compositous andl -um The alley starts faming pyph Euteete 75 Tempenakine in whiel odendtiten shard famming far He dor ally Copper pacentage) alloy consis Cu of Sopph Al ahd The cu tempenature 70 pph utactie [A +Cu Al ihich the CuY In Contains too pp Compaund alley tomponatane CUAI at 00m Ahes The dempenare in whick the alloy is too ppl is addecl to he Al. 5 y uilibi point when all 3stades in i Tt is he Indlicaled with Bowcincle farmed whea the metal first Coals thon t Doudsuts スe to form Solicl Cystal, tar liquids 8kte audl begins iThe ange of cuz anl 960'c of the olonduite fanmato temperature of he 7o 8 t30 A

Cu liaxid temperature iv The IS3'0 andl the contains looppl Compecud sox ) At 7oy B The 9eatge of tempehature he ko pph Eutectond at Room allby in loo pph 1450'c to tempent far 90% to lo A

(600 Oaderndiguid 153CA 90B10/ A Soudu-lenp -kepphEutectvid g018t301A) clentote fosmaliona temp. o+p A 20 30 40 50 B WT B du

(OR) All the temperature and ranges are shown in the following phase diagram of Aluminium alloy with copper

at% Cu 0 1.100 10 20 30 40 50 60 70 80 90 100 Bo 1,000 L 900 800 700 660.452 53.5 600 71- 548.2 567° 52.5 5.65 32.7 500 400 2 300 Al 20 30 10 40 50 60 70 80 90 Cu wt% Cu

Figure Equilibrium phase diagram of Aluminium alloy with copper