摘要
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 °C/1 s. 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.
基金
the National Key R&D Program of China(Nos.2019YFA0705300 and 2017YFA0700703)
the National Science and Technology Major Project of China(No.2019-VI-0006-0120)
the IMR Innovation Fund(No.2021-PY09)
the Doctoral Start-up Foundation of Liaoning Province(No.2020-BS-007).
