Surface and structural integrity evaluation of additively manufactured Scalmalloy®

Abstract Metal additive manufacturing has shown great potential for application in high-end equipment manufacturing due to its advantages, such as rapid prototyping of complex structures and weight reduction. The aluminum alloy Scalmalloy ® can increase this potential, but research on it is far less developed than on other aluminum alloys. This study investigates the influence of different post-processing methods on the surface, structural integrity of Scalmalloy ® components produced by laser powder bed fusion (LPBF). Three post-processing conditions were evaluated: optimized shot peening, machining, and machining followed by shot peening. The results demonstrate that fatigue performance is more strongly influenced by the distribution of residual stresses than by surface roughness. This indicates that a mechanical shot peening process provides greater benefits to the component than surface finishing alone. Moreover, combining machining, shot peening results in a further improvement in the structural performance of the component. This occurs despite the fact that mechanical shot peening, to induce significant compressive residual stresses, leads to a deterioration in surface integrity. These findings underscore the critical role of tailored post-processing techniques in maximizing the mechanical performance of LPBF-manufactured Scalmalloy ® components, paving the way for their broader use in demanding engineering applications