Use the phase diagram below A coppernickel alloy 53wt Ni and

Use the phase diagram below. A copper-nickel alloy (53wt% Ni and 47wt%Cu) is A) heated to 1400 degree C, and then B) rapidly cooled to 1300 degree C and keep at this temperature for long enough time to reach to an equilibrium condition; and then C) the temperature is quenched to room temperature. Determine the phase\'s after each process. Determine the composition of each phase under each condition after the process. Find the weight fraction of each phase/s under each condition after the process. Draw the microstructures after each process with composition and weight fraction being clearly indicated for each phase. Give the composition and the phase of the Au-Cu ally corresponding to point \'a\' marked in the phase diagram. Which material has the highest yield strength at room temperature, the Au-Cu alloy with the composition corresponding to point \"a\', pure element Cu. or pure element Ni? Which material has the highest melting point, the Au-Cu alloy with the composition corresponding to point \"a\', pure element Cu, or pure element Ni?

Solution

A) heat to 1400 --get liquid

a) cooled to 1300 back to where you were earlier, only the phases have not separated, you have to wait lomg enough and get back t o where you started.

b) quenched, means the phases are retained as they were at 1300C

B) composition of each phase : liquid of composition 53Ni 47Cu

Wt fractin of each phase 5/13, 8/13 from lever rule ( 5/13 matrix, 8/13 solid soln alpha)

Point a is solid soln alpha, composition 20% copper, 80% Ni

Best!!