激光冲击工艺对GH742镍基高温合金疲劳性能的影响  

Effects of laser shock processing on fatigue property of GH742 Ni-based superalloy

作　　者：何卫锋[1] 李应红[1] 周章文[1] 张永康[2] 汪诚[1] 

机构地区：[1]空军工程大学工程学院,陕西西安710038 [2]江苏大学机械工程学院,江苏镇江212013

出　　处：《材料热处理学报》2009年第3期42-45,共4页Transactions of Materials and Heat Treatment

基　　金：国防预研基金(513270103)

摘　　要：对两组镍基高温合金(GH742)试样进行激光冲击强化后,分别进行拉-拉疲劳试验和振动疲劳试验,并和未进行强化处理的试样进行对比,分析了强化试件的疲劳断口特征。结果表明激光冲击强化能提高镍基高温合金拉-拉疲劳寿命3.6倍以上,提高振动疲劳寿命2.4倍;强化后残余压应力影响层深度达1.0mm。Laser shock processing/peening （LSP） was carried out on a Ni-based superalloy GH742. The effect of LSP on fatigue property of the alloy was examined by axial fatigue and vibration fatigue tests, respectively. The residual stress in the specimens before and after LSP treatment was measured on a moire interferometry system and fatigue fracture surface was observed by SEM. Comparing with the non LSP treated specimens, the results show that LSP can increase axial fatigue life of Ni-based superalloy（GH742） to about 3.6 times, and the vibration fatigue life to 2.4 times. The depth of compressive residual stress is up to 1.0mm and the maximum value of compressive residual stress reaches - 1180MPa for the specimen after LSP treatment. It is believed that the high compressive residual stress formed in the specimen after LSP is responsible for the improvement of fatigue property of the Gh742 alloy.

关 键 词：镍基高温合金 激光冲击强化 疲劳 残余压应力 断口金相 

分 类 号：TG146.1[一般工业技术—材料科学与工程] O346.2[金属学及工艺—金属材料]