Q. A copper-aluminium diffusion couple develops a certain concentration profile after an isothermal treatment at 600°C for 10 hours. The time required to achieve the same concentration profile at 500°C is ______________(in hours to 1 decimal place)
Given: The interdiffusion coefficient for copper in aluminium at 500°C and 600°C are 4×10-14 m2s-1 and 8×10-13 m2s-1.