Micro-twinning is the major creep deformation mechanism in most Ni-based superalloys at temperatures above 700 °C. Nevertheless, many aspects of twin nucleation and growth remain unexplored. The Kolbe mechanism for micro-twinning is currently widely accepted in the community to explain these processes, based on post mortem TEM characterization and indirect theoretical estimations. However, this does not mean that other mechanisms cannot contribute to creep. Molecular dynamics (MD) simulations offer an alternative possibility to probe different creep mechanisms. In this work, we use MD simulations to demonstrate that a qualitatively different mechanism for nucleation and growth of twins can be competitive with the Kolbe mechanism in the intermediate temperature regime of 600 °C–800 °C. The proposed mechanism is closely related to the formation mechanism of super intrinsic stacking faults (SISFs) originally introduced by Condat and Decamps in 1987.

在 700 °C 以上的温度下，微孪晶是大多数镍基高温合金的主要蠕变变形机制。然而，双晶成核和生长的许多方面仍未得到探索。基于事后 TEM 表征和间接理论估计，微孪生的 Kolbe 机制目前在社区中被广泛接受以解释这些过程。然而，这并不意味着其他机制不会导致蠕变。分子动力学 (MD) 模拟提供了另一种探索不同蠕变机制的可能性。在这项工作中，我们使用 MD 模拟来证明在 600 °C–800 °C 的中间温度范围内，孪晶成核和生长的定性不同机制可以与 Kolbe 机制竞争。