Orientation-specific surface response of shot peening in laser powder bed fusion Ti-6Al-4V parts

Critical aerospace components, such as turbine blades and landing gears, are increasingly produced using additive manufacturing (AM), especially laser-powder-bed-fusion (LPBF) due to its design flexibility. However, the inherent high surface roughness and tensile residual stresses in LPBF parts compromise performance and dimensional stability. Shot peening, a surface work-hardening process, is an effective post-processing solution. The research objective is to understand the surface strengthening effect from grain refinement by inhomogeneous elastic-plastic deformation across surface orientations (0-90°) in AM parts. Peening parameters, specifically coverage and peening angle, are optimized to mitigate orientation-dependent surface properties in LPBF Ti64. Under optimized conditions, shot peening reduces AM deterministic features (i.e., large surface gradients and texture-induced area) by 90%. Notably, peening angle, an easily controllable parameter, has a stronger effect than coverage. These findings highlight shot peening’s potential in improving AM components, supporting complex designs.