Investigation of laser shock peening effects on residual stress state and fatigue performance of titanium alloys

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:536

Article

Maawad, E.¹  Sano, Y.²  Wagner, L.¹  Brokmeier, H. -G.¹  Genzel, Ch³ 

[1] Tech Univ Clausthal, Inst Mat Sci & Engn, D-38678 Clausthal Zellerfeld, Germany

[2] Toshiba Co Ltd, Isogo Ku, Yokohama, Kanagawa 2358523, Japan

[3] Helmholtz Zentrum Berlin BESSY II, D-12489 Berlin, Germany

关键词: Laser shock peening;    Fatigue;    Titanium alloys;    Residual stress;    Synchrotron X-ray diffraction;   

DOI  :  10.1016/j.msea.2011.12.072

来源: Elsevier

【 摘 要 】

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.

【 授权许可】

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