摘要
以Al-Cu-Li-Zr-Ce合金为研究对象,采用半定量分析统计方法,研究其断裂韧性机制,重点讨论时效时间和裂尖应力状态对合金分层开裂机制的影响。结果表明:随时效时间延长,起始区分层开裂特征所占比例越大,韧窝比例越小,甚至出现准解理特征;稳态扩展区,分层开裂为主要开裂机制;近失稳扩展区,分层比例下降,准解理逐渐成为主要断裂特征。随时效时间延长和裂纹扩展,分层厚度减小。分层裂纹的产生及扩展与主裂纹扩展及合金的时效时间有密切的关系。断裂韧性试样断口上分层比例较高时,合金可以获得较高的强度,同时保持相对较高的韧性。
The fracture mechanisms of Al-Cu-Li-Zr-Ce alloys aged for different time were studied by means of semi-quantity method.The effects of aging time and stress state of the crack tip on the fracture mechanisms were discussed.The results show that in the initial cracking area,with longer aging time the delamination percentage increases,the dimple percentage decreases,and even quasi-cleavage character appears.In the stable crack growth area,the delamination is the main fracture mechanism.However,in the near unstable crack growth area,the delamination percentage decreases and the quasi-cleavage become the main fracture mechanism gradually.The delamination thickness decreases with aging time prolonging and crack growing.The formation and propagation of the delamination cracks are significantly dependent on the main crack growth and the aging time of alloys.The higher delamination percentage leads to higher values both of toughness and strength.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2011年第2期331-334,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金(50941020
51075335
50875217)
