Deformation micro-twinning arising at high temperatures in a Ni-Co-based superalloy

Deformation twinning is an important deformation mechanism in nickel-based superalloys. For superalloys, deformation twins are generally observed at low or intermediate temperatures and high strain rates; however, the appearance of microtwins (MTs) at high temperatures has rarely been reported. In this study, transmission electron microscopy (TEM) was used to study MT formation in Ni-Co-based superalloys following compression at 1120 degrees C/1 s(-1). The deformation behavior was discussed in detail to reveal the mechanism of MT formation. The twinning mechanism at elevated temperatures was theoretically attributed to the low stacking fault energy (SFE) and poor dislocation-driven deformations caused by the high strain rate in specific directions. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Deformation twinning is an important mechanism in nickel-based superalloys. In this study, the formation of microtwins at high temperatures in Ni-Co-based superalloys was investigated using transmission electron microscopy. The results showed that the formation of microtwins at high temperatures can be attributed to the low stacking fault energy and poor dislocation-driven deformations caused by the high strain rate in specific directions.