Effects of cutting parameters on roughness and residual stress of maraging steel specimens produced by additive manufacturing

Abstract

Additive Manufacturing of metallic parts by powder bed fusion (PBF) has great potential to build complex geometries with innovative materials in a broad field of applications; however, it also presents some limitations as residual stresses, porosities, microcracks, and high roughness that restrict your plateau of productivity. Therefore, an alternative to improve the surface condition of PBF parts is the post-processing as milling. Maraging steel 300 is an important material used in the PBF process, considering its application in different segments, like automotive, tooling, and aerospace. Although there are a few works that investigated the effects of cutting parameters on the surface condition of maraging steel 300 components produced by PBF, this work investigated the effects of different cutting speeds (vc) and feed per tooth (fz) on average roughness Ra and residual stress of maraging 300 specimens. The lowest roughness level of Ra = 0.31 μm was obtained with fz = 0.02 mm/tooth and vc = 250 m/min. Furthermore, the cutting speed had a relevant effect on the compressive behavior of residual stresses. The feed per tooth combined with the cutting speed improved the surface roughness and the compressive residual stress of the specimens, showing the importance of considering both these parameters in the milling process planning of PBF maraging steel parts.