Investigation of laser shock peening effects on residual stress state and fatigue performance of titanium alloys
Investigation of laser shock peening effects on residual stress state and fatigue performance of titanium alloys
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DOI：
10.1016/j.msea.2011.12.072
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发表时间：
2012-02-28
期刊：
影响因子：
6.4
通讯作者：
Genzel, Ch
中科院分区：
文献类型：
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作者：
Maawad, E.;Sano, Y.;Genzel, Ch
激光冲击强化可以通过在比传统喷丸（SP）更深的表面层中诱导压缩残余应力来潜在地提高钛部件的疲劳寿命。在本研究中，高周疲劳（HCF）性能的α钛合金Ti-2.5Cu，（α + β）钛合金TIMETAL 54 M和亚稳β钛合金TIMETAL LCB激光冲击喷丸无涂层（LPwC）后进行了研究。疲劳结果解释通过检查的表面形貌，显微硬度和残余应力在表面层中产生的变化。此外，在老化的Ti-2.5Cu中的残余应力的热稳定性，作为一个例子，通过应用Zener-Wert-Avrami方法在各种升高的温度和暴露时间下退火LPwC处理的材料后进行评估。用同步辐射X射线衍射法和增量钻孔法测得了残余应力的深度分布。结果表明，Ti-2.5Cu和TIMETAL LCB的HCF性能在LPwC后显著改善，而TIMETAL 54 M的HCF性能则恶化。与LPwC相比，Ti-2.5Cu经球磨（BB）后获得了更好的10（7）疲劳强度。此外，LPwC引起的残余应力比喷丸引起的热更稳定。(C)2011 Elsevier B. V.保留所有权利。
Laser shock peening can potentially enhance fatigue life of titanium components by inducing compressive residual stresses in surface layers much deeper than caused by traditional shot peening (SP). In the present study, the high cycle fatigue (HCF) performance of alpha Ti-alloy Ti-2.5Cu, (alpha + beta) Ti-alloy TIMETAL 54M and the metastable beta Ti-alloy TIMETAL LCB was investigated after laser shock peening without coating (LPwC). The fatigue results were interpreted by examining the changes of surface morphology, microhardness and residual stress generated in the surface layer. Furthermore, thermal stability of residual stresses in aged Ti-2.5Cu, as an example, was evaluated after annealing LPwC-treated material at various elevated temperatures and exposure times by applying a Zener-Wert-Avrami approach. The depth profiles of residual stresses were obtained by means of synchrotron X-ray diffraction or by incremental hole drilling method. Results revealed that the HCF performance of Ti-2.5Cu and TIMETAL LCB was markedly improved after LPwC, while it was deteriorated in TIMETAL 54M. Compared to LPwC, better 10(7) fatigue strength of Ti-2.5Cu was obtained after ball-burnishing (BB). Moreover, LPwC-induced residual stresses are thermally more stable than shot peening-induced ones. (C) 2011 Elsevier B.V. All rights reserved.