Theory of ultrathin films at metal–ceramic interfaces

Abstract

A theoretical model for understanding the formation of interfacial thin films is presented, which combines density functional theory calculations for interface energies with thermodynamic modeling techniques for multicomponent bulk systems. The theory is applied to thin film formation in VC-doped WC–Co cemented carbides. It is predicted that ultrathin VC films may exist in WC/Co interfaces at the high temperature sintering conditions where most of the WC grain growth occurs, which provides an explanation of the grain growth inhibiting effect of VC additions in the WC–Co system.

Keywords:

• interface energy
• interface structure
• first-principles calculations
• cemented carbides
• grain growth inhibitors

Acknowledgements

The financial support from the Swedish Research Council, Sandvik and Seco Tools is gratefully acknowledged. Computations have been performed on SNIC resources. We thank Susanne Norgren, Sandvik Tooling, for providing thermodynamic calculations.

Notes

1. See the Online Supplementary Material for details on the DFT calculations.