5.1 A finite-source layer of A deposited onto the surface of matrix B diffused into it after heating to time t1 and the concentration profile versus distance was obtained.
a. How would you plot the concentration—distance data to obtain a straight line?
b. If the slope of the line is m, what is the value of the diffusion coefficient?
c. What additional information would be required to obtain the activation energy for diffusion?
5.2. In a couple composed of semi-infinite materials A and B bonded at x = 0, the concentration profile can be curve fit by the equation C (x, t) = 1/2 Erfc x/(4Dt)1/2 for ∞ > x > – ∞. The Matano analysis is designed to extract concentration-dependent diffusivity values from arbitrary diffusion-couple concentration ...