Evaluations of variant models for stacking fault energy based on γ-TiAl

ABSTRACT

The stacking fault energy (SFE) is of great significance to understand deformation behaviour of materials. Calculated by different models, the SFEs show differences and influence our understanding. Several typical models have been applied to γ-TiAl and discussed with Ab initio calculation systematically. Different models have a little effect on the calculated intrinsic stacking fault energy (ISFE), while affect the calculated unstable stacking fault energy (USFE) a lot. An alias-to-affine deformation transform is being found in 6-layer model. The local energy analysis indicates it is caused by the intrinsic properties of the materials. Combined with experiment observation and theoretical prediction, deformation patterns are compared and discussed.

KEYWORDS:

• γ-TiAl
• stacking fault energy
• Ab initio
• local energy
• deformation pattern

Acknowledgement

The authors thank Professor Bučko Tomáš for fruitful discussions. Computations were partly performed on the SR16000 supercomputer of Institute for Materials Research, Tohoku University and High Performance Computing Center, Shanghai University. The present study was supported by National Key R&D Program of China (2017YFB0304402) and Shanghai Municipal Natural Science Foundation (17ZR1410400).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Natural Science Foundation of Shanghai: [Grant Number 17ZR1410400]; National Key R&D Program of China: [Grant Number 2017YFB0304402].