Consider a diffusion couple of metals A and B$,$ with inert markers initially positioned at the

A$/$B interface. Sketch the final composition profile and marker position after diffusion for a

reasonable time, assuming that, a$)$ A and $B$ are completely soluble in each other and the

intrinsic diffusibilities of A and $B$ are approximately equal. b$)$ A and $B$ have the following

phase diagram and the intrinsic diffusivity of $A$ is greater than that of $B.$