高温下钨断裂及氢影响钨断裂的分子动力学模拟

Molecular Dynamic Simulation of Fracture and Effect of Hydrogen on Fracture of Tungsten at High Temperature

关键词:  分子动力学  钨  断裂  嵌入原子理论

Key words:  molecular dynamic simulation  Tungsten  fracture  embedded atom method

摘要:

用分子动力学模拟在1000K温度下单晶钨在单轴应变的情形下断裂和氢对钨断裂的影响。结果表明:{100}面的辟裂比{110}面要容易。{100}面的辟裂与裂纹尖端的取向有关,模拟结果与低温下的实验结果符合得比较好。{110}面<111>方向的断裂不是辟裂方式。切应变的模拟结果也与实验相符。氢的加入对裂纹尖端影响比较大,能显著降低应力。

Abstract:

The fracture of Tungsten single crystal has been investigated under uniaxial strain at temperature 1000 K.The results indicate that the {100} plane cleaves more easily than the {110} plane.The cleavage of the {100} plane depends on the orientation of the crack-tip.The result is in good agreement with the experiment at low temperature.The simulation for the fracture of the (110)<111> indicates that the fracture mechanism is not cleavage.Two cases of shear strain are also studied.The present results are also coincident with available experiments of room temperature.The present results indicate that the fracture of Tungsten at high temperature is similar to that at low temperature.The effect of Hydrogen on the fracture is also discussed.It can affect the front of the crack-tip and decrease the yield stress.