论文部分内容阅读
本文通过对310不锈钢薄膜进行透射电子显微镜的原位拉伸观察,研究了韧断微裂纹的形核及向空洞的转化过程,并用细观断裂力学研究微裂纹的形核机理,结果表明,裂尖或其附近位错源发射位错后,裂尖仍有可能保持不钝化,裂尖无位错区是一个高应变的弹性区,裂尖局部区域内的应力可以达到原子键合力,从而导致一个或多个解理微裂纹优先在无位错区中形核,通过微裂纹发射位错或周围位错源的开动,微裂纹钝化成空洞,和主裂纹连接后导致塑性裂纹的“Z”字型扩展,微裂纹也可在钝化的主裂纹顶端形核,通过钝化、再形核方式导致韧断裂纹的连续扩展。
In this paper, 310 stainless steel thin films were observed by transmission electron microscope in situ tensile study of the micro-fracture tough fracture micro-nucleation and the process of conversion to hollow, and micro-fracture mechanics study of the nucleation mechanism of micro-cracks, the results show that cracking After the tip or nearby dislocation source emits dislocations, the crack tip may still remain unpassivated, and the dislocation-free zone is a high-strain elastic zone, and the stress in the local area of the crack tip can reach the atomic bonding force, so that Resulting in one or more cleavage microcracks preferentially nucleating in the dislocation-free zone. Passing of the microcrack launch dislocations or the surrounding dislocation sources, the microcracks are passivated into voids and the “Z” character of the plastic crack after being connected to the main crack Type of expansion, micro-cracks can also be in the top of the passivation of the main crack nucleation, passivation, re-nucleation mode led to the continuous expansion of ductile fracture.