Diffusion

· In technical materials, other diffusion paths can influence the transport of a material into the sample. The role of Grain Boundaries, Dislocations and Surfaces is illustrated.
· The defects change both the Activation Energy and the pre-exponential term in the temperature dependent Diffusion coefficient, D(T).
· The area of the different paths must be taken into account when determining their effect on material penetration into the sample.

From: Guy, "Introduction to Materials Science," McGraw Hill (19972)