Figure below shows a schematic phase diagram of Al - Cu alloy with Al melting point of 660 C, eutectic temperature 548 C, maximum solubility of Cu in Al = 5.65 wt%, and eutectic composition Xcu 33 wt%. (All phase boundaries are straight lines.) The diffusion coefficient for the liquid D = 3 x 10.9 ms. Temperature, "C 700 Al-Cu 660 600- 548 500 0 5' 10 15 20 25 30 35 5.65 Xcu (%) 33 If an Al - 0.5 wt% Cu alloy is solidified with no convection and a planar solid/liquid interface at 5.0 m/s, (a) What is the interface temperature in the steady state? (b) What is the thickness of the diffusion layer? (c) What temperature gradient will be required to maintain a planar interface?