Mechanical and Fatigue Properties of a Laser Powder Bed Fusion Ti6Al4V Alloy: A Review

Laser Powder Bed Fusion (LPBF) enables the manufacturing of complex Ti6Al4V components, but the resulting mechanical and fatigue responses are condition-dependent. This critical narrative review examines how alloy grade and interstitial chemistry, powder history, processing, microstructure, residual stress, defect population, surface condition and post-processing affect quasi-static behaviour and low-, high- and very-high-cycle fatigue behaviour. Reported properties are compared with the associated material and test data, including surface condition, build orientation, stress ratio, loading mode, stress definition and run-out criterion. The review distinguishes finite-life fatigue strength from a demonstrated fatigue limit and separates stress-life data from strain-life and crack-growth parameters. The resulting condition-specific synthesis is intended to support engineering comparison and numerical modelling without treating LPBF Ti6Al4V as a single universal material dataset.