Atomistic simulation of fracture in Ni_3Al
Atomistic simulation of fracture in Ni_3Al
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DOI：
10.1557/jmr.2008.0192
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发表时间：
2008-06
影响因子：
2.7
通讯作者：
Hongxian Xie;Chong-yu Wang;Tao Yu
中科院分区：
文献类型：
--
作者：
Hongxian Xie;Chong-yu Wang;Tao Yu
用分子动力学方法模拟了Ni_3Al的I型裂纹。研究了裂纹的原子组态演化过程。模拟结果表明，低温下，裂纹扩展开始前先发射出Shockley部分位错，在裂纹尖端（111）面上形成伪孪晶，然后发生裂纹解理。在模拟过程中，裂纹解理伴随着Shockley部分位错的发射。在较高温度下，裂纹尖端的钝化是由（100）面上发射的[110]超位错引起的。本工作还表明，在1/2[110]位错核中的（111）面上可以形成偶极位错。
The molecular dynamics method has been used to simulate mode I cracking in Ni_3Al. Close attention has been paid to the process of atomic configuration evolution of the cracks. The simulation results show that at low temperature, the Shockley partial dislocations are emitted before the initiation of the crack propagation, subsequently forming the pseudo-twins on (111) planes in crack-tip zone, and then the crack cleavage occurs. The emitting of the Shockley partial dislocations accompanies the crack cleavage during the simulation process. At the higher temperature, the blunting at the crack tip is caused by the [110] superdislocations emitted on (100) plane. The present work also shows that the dipole dislocations on (111) planes in the 1/2[110] dislocation core can be formed.