Zr—4合金单调和循环变形结构的扫描电镜原位观察

In Situ SEM Observation of Monotonic and Cyclic Deformed Structure in Zircaloy4

摘要:

利用ＳＥＭ原位观察了Ｚｒ－４合金单调和循环变形过程中，试样表面滑移，裂纹萌生及扩展特征。结果表明：拉伸过程中，随着外应力增大，滑移程度加剧，从单滑移逐渐向多滑移转化；

Abstract:

Slippage, crack nucleation, propagation are analyzed for zircaloy4 during monotonic and cyclic deformation by means of insitu SEM observation. The results show that in the course of tension testing the slippage becomes heavier, and changes from single slip to multiple slips as the applied stress increases. Twist plays an important role in maintaining homogeneous deformation in the final deformation stage. The specimen fracture occurs as soon as the cracks reach the specimen surface. During cycling, a number of cracks nucleate, propagate and link in the vicinity of the grain boundaries. TEM observation shows that a typical dislocation configuration is parallel dislocation lines in transverse section and embryonic dislocation cells in longitudinal section.