Abstract Incipient plasticity and dislocation loop (DL) evolution are two important plastic behaviors of ceramic materials. In this work, we performed molecular dynamics simulations of the nanoindentation on vanadium nitride (VN) surfaces with different Miller indexes to investigate the incipient plasticity, dislocation reactions, and the evolution of the DLs. It was found that the plasticity of VN proceeds by the nucleation and glide of partial dislocations, forming {111} stacking fault (SF). However, dislocation patterns of nanoindentation along different crystallographic orientations are quite different, which to be specific are dislocation flower for {001}, SF tripyramid for {111}, and symmetric inclined SF for {110} indentions. There are two kinds of reactions between the primary defects, including the movement of two parallel partial dislocations forming an extended dislocation, and the intersection of two unparallel SFs forming a stair-rod dislocation. The Thompson tetrahedron was extended to the illustration of the evolution of the microstructures in B1 crystalline VN during the nano-indentations on differently oriented surfaces.

中文翻译：

---

岩盐氮化钒的初始塑性和位错环演化

摘要 初始塑性和位错环（DL）演化是陶瓷材料的两种重要塑性行为。在这项工作中，我们使用不同的米勒指数对氮化钒 (VN) 表面的纳米压痕进行了分子动力学模拟，以研究初始塑性、位错反应和 DLs 的演变。发现 VN 的塑性通过部分位错的成核和滑移进行，形成 {111} 堆垛层错 (SF)。然而，沿不同​​晶体取向的纳米压痕的位错模式有很大不同，具体是{001}的位错花，{111}的SF三棱锥和{110}的对称倾斜SF。初级缺陷之间有两种反应，包括两个平行的部分位错的运动形成一个扩展的位错，以及两个不平行的 SFs 的相交形成一个阶梯状位错。汤普森四面体被扩展到在不同取向表面上的纳米压痕期间 B1 结晶 VN 中微观结构的演变的说明。