Influence of process parameters on residual stress in laser metal deposition of nickel-based superalloy

Abstract

This paper studied the impac t of process parameters in laser metal deposition on distribution and magnitude of residual stresses. A finite element method was used to create a residual stress model with parameters as variables. The study used a Taguchi L32 experimental design, with four levels for each parameter, and analyzed residual stresses along critical paths using quadratic functions. The results reveal that the impact of process parameters varies across different regions of the component. Melt pool size primarily affects the location of maximum residual stresses at the interface between the substrate and the deposited layer. Deposition length affects the concentration of residual stresses at the center of the interface between the substrate and the deposited layer. Substrate thickness has a substantial impact on residual stresses. Scanning strategy influences residual stresses at the edges of the upper surface of the deposited layer. Boundary conditions and yield strength affect residual stresses in various regions of the deposited layer. The coefficient of thermal expansion influences residual stresses at the interface between the base material and the deposited layer.