Synergistic enhancement of strength and plasticity for laser direct energy deposited Ti60 joint by locally applied laser shock peening

Abstract

This study employed a composite method of laser direct energy deposition (LDED) and laser shock peening (LSP) to repair Ti60 alloy. The results showed that the spherical α_p phase dissolved and the clustered α_s lamellae transform into basketweave α plates from the substrate zone (SZ) to heat affected zone (HAZ) and laser deposition zone (LDZ) in the LDEDed joint. These microstructure differences resulted in the SZ becoming the weak strength side, dominating the tensile properties of the LDEDed joint. LSP treatment was performed only on the SZ side, improving the tensile strength of the SZ and activating the inherent plastic deformation capabilities of the LDZ, thereby achieving a synergistic enhancement of the strength and plasticity of the repaired Ti60 parts.