高周疲劳条件下激光温喷丸TC4钛合金的残余应力释放规律及疲劳特性  

Residual Stress Relaxation and Fatigue Properties of TC4 Titanium Alloy Induced by Warm Laser Peening under High-Cycle Fatigue

作　　者：孟宪凯[1] 周建忠[1] 黄舒[1] 盛杰[1] 韩煜航[1] 朱炜立 陈寒松[1] 苏纯[1,2] 

机构地区：[1]江苏大学,江苏镇江212013 [2]常州工学院,江苏常州213002

出　　处：《稀有金属材料与工程》2015年第5期1185-1190,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51175236);高等学校博士学科点专项科研基金(20123227110022);中国博士后科学基金54批面上项目(2013M540417);江苏省科技工业支撑项目(BE2013097);江苏大学高级人才启动基金(13JDG109);江苏省自然科学基金(BK20141166)

摘　　要：使用Nd:YAG纳秒激光器分别在试样表面温度为20、100、200、300以及400℃下对TC4钛合金狗骨状拉伸试样进行激光喷丸表面强化,然后使用疲劳试验机在高周疲劳条件下对试样进行残余应力释放测试与疲劳寿命测试,并使用热场发射扫描电镜研究激光温喷丸后试样的断口特点。结果表明,经过10 000次循环载荷后,试样表面温度为20、100、200、300及400℃时激光喷丸TC4钛合金试样的残余压应力幅值分别下降至–100、–75、–132、–196与–146 MPa;由于较高的残余压应力幅值及较低的残余应力释放速度,300℃时激光温喷丸试样的疲劳条带间距约为0.42μm,比20℃激光喷丸降低了约64%;300℃时激光温喷丸试样的疲劳寿命高达147 846次,约为20℃激光喷丸试样的1.7倍。Warm laser peening（WLP） of TC4 titanium alloy were conducted when the sample surfacing temperature was 20, 100, 200, 300 and 400 ℃, using Nd： YAG nanosecond laser, and then residual stress relaxation and fatigue experiments were carried out by an electro-hydraulic servo fatigue testing machine. The fatigue fractures of TC4 titanium alloy were analyzed by scanning electron microscope（SEM）. The results show that the residual stress amplitude of TC4 samples treated by WLP at 20, 100, 200, 300 and 400 ℃ decreases to –100, –75, –132, –196 and –146 MPa, respectively. Due to the high amplitude and low relaxation rate of compressive residual stress, the fatigue striation spacing of the TC4 samples treated by WLP at 300 ℃ is about 0.42 μm, 64% lower than that of LP treated samples at 20 ℃. The fatigue life of the TC4 samples treated by WLP at 300 ℃ is 147 846 cycles, which is 1.7 times of that of samples treated by LP at 20 ℃.

关 键 词：激光光学 残余应力释放 高周疲劳 激光温喷丸 TC4钛合金 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG115.57[金属学及工艺—金属材料]