(上海交通大学 材料科学与工程学院, 上海 200030)
摘 要: 采用缀加平面波加局域轨道方法和广义梯度近似对立方C15结构的ZrCr2 Laves相金属间化合物的弹性性质, 包括弹性常数和弹性模量, 以及层错能进行理论计算。 结果表明: 计算得到的ZrCr2 Laves相的弹性性质与实验结果相近, 其泊松比和弹性各向异性系数大小说明ZrCr2 中原子键合的方向性并不强烈; ZrCr2 Laves相的内禀和外禀层错能分别为112 mJ/m2和98 mJ/m2。 并计算了层错与位错的弹性交互作用。 对ZrCr2 Laves相的力学特性和变形机制进行了讨论。
关键字: 弹性常数; 弹性模量; 堆垛层错能; ZrCr2 Laves 相; 第一性原理
(School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China)
Abstract: First-principles calculations were performed to investigate the elastic constants, elastic moduli, stacking fault energies, and dislocation dissociations of C15 ZrCr2 Laves phase, based on the method of augmented plane waves plus local orbitals with generalized gradient approximation. The results show that the calculated elastic properties are close to the experimental results. The high value of Poisson's ratio and low value of elastic anisotropy ratio imply that the interatomic force in ZrCr2 is weakly directional. The intrinsic and extrinsic stacking fault energies of ZrCr2 Laves phase are found to be 112 mJ/m2 and 98 mJ/m2, respectively, and the elastic interactions between faults and dislocations are considered. Finally, the mechanical properties and deformation mechanism of ZrCr2 Laves phase are discussed with the calculated results.
Key words: elastic constant; elastic modulus; stacking fault energy; ZrCr2 Laves phase; First-principles