On the fatigue behaviour and modelling of fatigue life for laser-welded Ti-6Al-4V

Abstract

This aim of this work is to investigate the fatigue behaviour of laser-welded Ti-6Al-4V titanium alloy in the region of high cycle fatigue. The crack initiation mechanism and the influence of weld defects on fatigue performance were comprehensively studied. A set of post-weld treatments that can mitigate the effect of inherent weld imperfections and thereby extend the fatigue life were analysed. A robust and efficient analytical assessment model for internally-flawed materials has been developed based on a fracture mechanics approach. The developed methodology can be used for the reliability assessment of components with various types of defects, thus enabling a defect-tolerant design of welded structures.