Kinetic pinning versus capillary pinning of voids at the moving interface during reactive diffusion

Abstract

Two mechanisms of the Kirkendall voids pinning at the moving interface are discussed. Besides common Zener pinning, voids can be additionally, kinetically pinned to the interface by the additional vacancy concentration gradient, existing due to unideal vacancy sinks/sources at the interface and at the both sides of it. Kinetic pinning may explain the influence of copper substrate defect prehistory on the pinning behaviour. Capillary pinning is difficult to apply for the cases of voids enveloping by the growing phase.

Keywords:

• Voiding
• diffusion
• kinetics of reaction
• intermetallic compounds
• vacancies
• pinning

Acknowledgements

Authors are grateful to O. Liashenko and M. Pasichnyy for SEM images, to L. Jeurgens, R. Kozubski for fruitful discussions.