Kinetics and Microstructural Control

· A comparison of the rates for heterogeneous and homogeneous nucleation processes is shown.
· The heterogeneous process needs less undercooling to reach its maximum nucleation rate.
· The transport processes for the two mechanisms are the same. The heterogeneous process will, therefore, dominate the phase transition reaction if it is allowed by the transformation conditions.

From: Barrrett, Nix & Tetelman,
"The Principles of Engineering Materials,"
Prentice Hall (1973)