论文部分内容阅读
本文报道了α-Ti拉伸裂纹成核和扩展的高压电镜动态观察的实验结果,完整地观察到位错运动导致滑移带两端形成滑移台阶,由于应力集中,在滑移台阶处裂纹成核,并在应力作用下扩展。裂纹扩展有两种方式:(1)在应力作用下裂纹尖端塑性区减薄,裂纹以不连续的方式沿着减薄区扩展;(2)主裂纹与其前端的微裂纹或孔洞联结导致扩展。文章还指出,在α-Ti中晶界可能不是裂纹成核的择优地点和裂纹扩展的优先路径。
In this paper, experimental results of high-pressure electron microscopy (TEM) observation of α-Ti tensile crack nucleation and propagation are reported. Completely observed dislocation movement leads to the formation of slip steps at both ends of the slip band. Due to stress concentration, Nuclear and expand under stress. There are two ways to crack propagation: (1) the plastic zone at the crack tip is thinned under stress and the crack propagates along the thinning zone in a discontinuous manner; (2) the main crack and the micro-crack or hole at the front end of the crack propagate. The article also points out that the grain boundary in α-Ti may not be the preferred path for crack nucleation and the preferred path for crack propagation.