1. The activation energy for the diffusion of cop- per in silver is 193,000 J/mol. Calculate the diffusion coefficient at 1200 K (927°C), given that D at 1000 K (727°C) is 1.0 X 10-14 m2/s.
2. The diffusion coefficients for nickel in iron are given at two temperatures:
T(K) D(m2/s)
C/cm3 Fe, which are maintained constant. If the preexponential and activation energy are 6.2 X 10-7 m2/s and 80,000 J/mol, respectively, compute the temperature at which the diffu- sion flux is 6.3 X 10-10 kg/m2-s.