论文标题
卑诗省延性衰竭的原子模拟高熵合金
Atomistic simulations of ductile failure in a b.c.c. high entropy alloy
论文作者
论文摘要
在BCC HFNBTAZR高熵合金（HEA）中研究了延性衰竭，并具有先前存在的空隙。使用单轴拉伸测试的分子动力学模拟，我们探索了void半径对弹性模量和屈服应力的影响。弹性模量的孔隙率与闭孔泡沫一样。考虑到HEA的较大核心半径，设计的模型很好地描述了位错成核与空隙半径的函数的临界应力。双胞胎是作为互补变形机制进行的，并且在大菌株下发生了一些去威先生。未鉴定固体固相变。元素大小不匹配和可塑性的并发影响导致晶格障碍。通过将我们的HEA结果与纯触角模拟进行比较，我们表明，脱位成核的临界应力和所得的脱位密度远低于纯TA，这是由于化学障碍所预期的。
Ductile failure is studied in a bcc HfNbTaZr High Entropy Alloy (HEA) with a pre-existing void. Using molecular dynamics simulations of uniaxial tensile tests, we explore the effect of void radius on the elastic modulus and yield stress. The elastic modulus scales with porosity as in closed-cell foams. The critical stress for dislocation nucleation as a function of the void radius is very well described by a model designed after pure bcc metals, taking into account a larger core radius for the HEA. Twinning takes place as a complementary deformation mechanism, and some detwinning occurs at large strain. No solid-solid phase transitions are identified. The concurrent effects of element size mismatch and plasticity lead to significant lattice disorder. By comparing our HEA results to pure tantalum simulations, we show that the critical stress for dislocation nucleation and the resulting dislocation densities are much lower than for pure Ta, as expected from lower energy barriers due to chemical complexity
