Effects of laser peening on residual stresses and fatigue crack growth properties of Ti–6Al–4V titanium alloy

• Published in: Optics and lasers in engineering Vol. 52; pp. 189 - 194
• Main Authors: Zhou, J.Z., Huang, S., Zuo, L.D., Meng, X.K., Sheng, J., Tian, Q., Han, Y.H., Zhu, W.L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2014
• Subjects: Compressive properties; Coverage rate; Crack propagation; Cross sections; Fatigue crack growth rate; Fatigue failure; Fracture mechanics; Laser peening; Lasers; Peening; Residual stress; Ti–6Al–4V titanium alloy; Ti–6Al–4V titanium alloy; Coverage rate; Fatigue crack growth rate; Residual stress; Laser peening
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2013.06.011

The effects of laser peening (LP) with different laser peening coverage rates on residual stresses and fatigue crack growth (FCG) properties of Ti–6Al–4V titanium alloy were investigated. Residual stresses after LP and micro-structure with different fatigue striation patterns on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be obtained in the superficial layer after LP. The influence of compressive residual stresses induced under different LP coverage rates on FCG properties was revealed. LP coverage rate had an apparent influence on FCG properties as confirmed by the fatigue striation spacing on fracture cross-sections. Moreover, FCG rate decreased with the increase of compressive residual stresses perpendicular to the crack growth direction, which indicated that LP had an obvious inhibitory effects on FCG. •Effects of LP with different coverage rates on residual stresses were studied.•Effects of residual stresses on effective SIF at crack tip were discussed.•Effects of LP on Fatigue striation pattern were studied.•Effects of LP with different coverage rates on FCG life and FCG rate were studied.