Zhang Zhiwei, Fu Qiang, Wang Jun, Yang Rong, Xiao Pan, Ke Fujiu, Lu Chunsheng
State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
Aero Engine Academy of China, Beijing, 101304, China.
Phys Chem Chem Phys. 2021 May 5;23(17):10377-10383. doi: 10.1039/d1cp00741f.
Understanding the interactions between planar defects and complex dislocation structures in a material is of great significance to simplify its design. In this paper, we show that, from an atomistic perspective, by using molecular dynamics simulations on nanoindentations, a prismatic dislocation loop in Ni3Al appears in pairs with a butterfly-like shape. The planar defects in Ni3Al can effectively block the movement of the prismatic dislocation loop pairs and play a hardening role. Among the impediment factors, twinning boundaries are the strongest and antiphase boundaries are the weakest. Superlattice intrinsic and complex stacking faults have basically the same blocking effect. Furthermore, we systematically elucidate the hardening effects and interaction mechanisms between the prismatic dislocation loop pairs and planar defects. These findings provide novel insights into the nanostructured design of materials with excellent mechanical properties.
