激光冲击强化对Ti-6Al-4V榫齿结构高低周复合疲劳性能的影响
Effect of Laser Shock Peening on Combined High and Low Cycle Fatigue Performance of Ti-6Al-4V Dovetail Joint
牛志强 1门豪杰 1史淑艳 1曹子文 2周文龙 1陈国清 1付雪松3
作者信息
- 1. 大连理工大学材料科学与工程学院,辽宁大连 116024
- 2. 中国航空制造技术研究院,北京 100024
- 3. 大连理工大学材料科学与工程学院,辽宁大连 116024;大连理工(营口)新材料工程中心有限公司,辽宁营口 115004
- 折叠
摘要
为了探究激光冲击强化对Ti-6Al-4V合金榫齿结构高低周复合疲劳行为的影响,本文对经过激光冲击强化处理的Ti-6Al-4V榫齿结构的表面完整性特征和高低周复合疲劳性能进行测试.结果表明:相比于未经过激光冲击强化处理的原始榫齿结构,激光冲击榫齿结构的高低周复合疲劳寿命提高 729%.激光冲击改变了榫齿结构接触区域的微动磨损特征.原始榫齿结构表现为大尺寸的脱层磨损坑,坑底部诱发微裂纹并向基体内扩展,而激光冲击榫齿结构表现为小尺寸脱层薄片.此外,激光冲击还降低榫齿结构的疲劳裂纹扩展速率.激光冲击强化抗高低周复合疲劳作用显著,这主要归因于激光冲击强化层改变疲劳裂纹萌生方式,并抑制裂纹早期扩展.
Abstract
In order to investigate the effect of laser shock peening(LSP)on the combined high and low cycle(CHLC)fatigue behavior of Ti-6Al-4V alloy dovetail joint,the surface integrity characteristics and combined high and low cycle(CHLC)fatigue performance of laser shock peened Ti-6Al-4V dovetail joints were tested in this paper.The results show that compared with the as-machined(AM)specimens without laser shock peening treatment,the CHLC fatigue life of the LSP specimens increases by 729%.Laser shock peening changed the fretting wear characteristics of the contact zone of the dovetail joints.The AM specimens exhibited large-sized delamination wear pits,and microcracks were induced at the bottom of the pits and extended into the matrix.The LSP specimens showed small-sized delamination flakes.In addition,Laser shock peening also reduced the fatigue crack propagation rate of the dovetail joints.Laser shock peening can significantly improve the CHLC fatigue life,because the LSP layer changes the fatigue crack initiation mode and inhibits the early crack propagation.
关键词
激光冲击强化/高低周复合疲劳/Ti-6Al-4V/残余压应力Key words
laser shock peening/combined high and low cycle fatigue/Ti-6Al-4V/residual compressive stress引用本文复制引用
基金项目
国家自然科学基金(51975084)
国家科技重大专项(J2019-Ⅳ-0012-0080)
辽宁省自然科学基金(2022-YKLH-04)
出版年
2024
NETL
NSTL
万方数据