Research on the residual stress distribution of aircraft engine blades repaired by laser shock peening and laser cladding composite process

The traditional laser cladding (LC) repair process for aircraft blades introduces residual tensile stress near the heat affected zone, which causes a decrease in the strength of the joint interface of the repaired part. This study proposes laser shock peening (LSP) before LC to improve the residual stress distribution of the repaired parts and thus enhance their strength. GH4169 superalloy was selected as the research material, a Swift-Voce constitutive model was constructed based on tensile testing. A full process finite element model of LSP and LC composite process, based on historical data transfer, was constructed. Residual stress distribution was analysed using this FE model. The results show that LSP introduces residual compressive stress in the impact area. As the peak pressure of laser shock wave increases, the residual compressive stress in the impact area first increases and then tends to stabilize. LC will introduce residual tensile stress into the base material and cladding layer, and the maximum residual tensile stress occurs at the edge of the cladding material specifically at the weld seam. LSP can effectively improve the residual stress distribution, primarily by reducing residual tensile stress, improving the uniformity of stress distribution and avoiding stress concentration.