Question

3. (i). (3 points) Which of the diffusion is faster, interstitial diffusion or vacancy diffusion? And Why? (ii) (4 points) Which one has the greatest magnitudes of the diffusion coefficients: (A)N in Fe at 600 K (B) Cr in Fe at 600 K (C)N in Fe at 900 K (D)Cr in Fe at 900 K And justify your choice. (iii) (10 points) The diffusion coefficients for iron in nickel are given at two temperatures: (а)Determine the values of Do and the activation energy Qa. (b)What is the magnitude of D at 1100°C (1373 K)?

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