LAUSR

Laser shock peening (LSP) is an attractive post-processing method to tailor surface microstructure and enhance mechanical performances of additive manufactured (AM) components. The effects of multiple LSP treatments on the microstructure and mechanical properties of Ti-6Al-4V part produced by electron beam melting (EBM), as a mature AM process, were studied in this work. Microstructure, surface topography, residual stress, and tensile performance of EBM-manufactured Ti-6Al–4V specimens were systematically analyzed subjected to different LSP treatments. The distribution of porosities in EBM sample was assessed via X-ray computed tomography. The results showed that EBM samples with two LSP treatments possessed a lower porosity value of 0.05% compared to the value of 0.08% for the untreated samples. The strength of EBM samples with two LSP treatments was remarkably raised by 12% as compared with the as-built samples. The grains of α phase were refined in near-surface layer, and a dramatic increase in the depth and magnitude of compressive residual stress (CRS) was achieved in EBM sample with multiple LSP treatments. The grain refinement of α phase and CRS with larger depth were responsible for the strength enhancement of EBM samples with two LSP treatments.