ABSTRACT

An understanding of nucleation, growth and coalescence of voids is required to predict the spall fracture. We employ molecular dynamics simulations to investigate the effect of temperature on the nucleation and growth of voids in single crystal copper under triaxial loading condition. We find that the void density decreases with an increase in temperature. The nucleation rate of the voids diminishes as temperature increases for the range of 300–1250 K. The individual void volume fraction evolves with discrete jumps due to coalescence events. The overall void volume fraction at 1250 K appears earlier than that at 300 K indicating the failure of the material earlier at higher temperatures. The void dimensions evolve with discrete jumps due to coalescence of the voids. The void dimensions change with the applied temperature. The void size distribution at each applied temperature follows a polynomial function.

摘要

需要了解空隙的成核，生长和聚结才能预测剥落破裂。我们采用分子动力学模拟来研究温度对三轴加载条件下单晶铜中空核形核和空洞生长的影响。我们发现，空隙密度随温度的升高而降低。在300–1250 K的范围内，空隙的成核速率随温度的升高而减小。由于聚结事件，单个空隙的体积分数随离散跃迁而演化。在1250 K时的总空隙体积分数要比在300 K时的空隙体积分数更早出现，这表明该材料在较高温度下更容易失效。由于空隙的合并，空隙尺寸随着离散的跳跃而发展。空隙尺寸随施加的温度而变化。