W-K合金中空位型缺陷的浓度和尺寸研究

Study on the concentration and size of vacancy defect in W-K alloy

W-K合金具有熔点高,抗热冲击性能强,抗氢氦等离子辐照能力强等众多优点,特别是钾泡的形成能稳定晶界、充当钉扎点和细化晶粒的作用,从而改善了W-K合金材料的性能.由于正电子寿命谱分析技术对纳米尺度的空位型缺陷极为敏感,因此本文采用该方法测量了正电子在不同钾含量下W-K合金的寿命值大小和相应的强度,并依据正电子湮没的两态捕获模型,对拟合的正电子寿命成分进行数据处理,同时对钾泡浓度和尺寸的变化情况进行了分析和讨论.

W-K alloy has many advantages,such as high melting point,the resistance to thermal shock,and excellent resistance to helium hydrogen plasma irradiation.The key is the formation of potassium bubbles which can stabilize the grain boundary,acting as pinning point and refine grain of W-K alloy,and thus the properties of materials can been greatly improved.Positron annihilation lifetime spectroscopy(PLAS)is extremely sensitive to the concentration and size of nanoscale defects.In this paper,the values of positron lifetime in W-K alloy at different potassium contents ware measured by using the method of positron annihilation lifetime spectroscopy.According to the two-state capture model,the positron lifetime spectrum was fitted as two-lifetime component,and the data were processed and used to analyze the change of concentration and size of potassium bubble in the W-K samples.