2397合金高周疲劳性能及裂纹萌生扩展行为  

High-Cycle Fatigue Properties and Crack Initiation and Propagation Behavior of 2397 Alloy

作　　者：范雪松[1] 郑子樵[1] 张龙[1] 胡芳[1] 龚铸[1] 

机构地区：[1]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083

出　　处：《稀有金属材料与工程》2017年第5期1327-1333,共7页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展规划("973"计划)(2012CB619503)

摘　　要：研究了2397-T87铝锂合金的高周疲劳性能及裂纹萌生扩展行为。结果表明:在应力比R=0.1时,2397-T87铝锂合金L方向、LT方向和ST方向光滑试样(K_t=1.0)的疲劳寿命极限分别约为192,243和151 MPa;缺口试样(K_t=3.0)的疲劳寿命极限分别约为72,78和70 MPa。其疲劳裂纹主要萌生于试样表面,以及氧化物、夹杂等脱落形成的空洞,Al(CuFeMn)第二相杂质粒子。驻留滑移带(PSB)和晶粒取向对其疲劳裂纹早期扩展有重要影响。The high-cycle fatigue properties and crack initiation and propagation behavior of 2397-T87 Al-Li alloy were investigated. The results show that when the stress ratio R is 0.1, the fatigue limit of smooth specimens of 2397-T87 Al-Li alloy in the L orientation, LT orientation and ST orientation are about 192 MPa, 243 MPa and 151 MPa, respectively. The fatigue limit of notch specimens in the L orientation, LT orientation and ST orientation are about 72 MPa, 78 MPa and 70 MPa, respectively. Fatigue crack initiation of this alloy mainly occurs on the sample surface, with initiation from the defects caused by the oxides and inclusions, the AI（CuMnFe） secondary phases. Persistent slip bands （PSB） and grain orientation have important influence on fatigue crack propagation at the early stage.

关 键 词：2397合金 高周疲劳性能 裂纹萌生 裂纹扩展 

分 类 号：TG146.21[一般工业技术—材料科学与工程]