Characterization of maraging steel 300 internal surface created by selective laser melting (SLM) after abrasive flow machining (AFM)

Abstract

Conformal cooling channel gains growing acceptance and becomes increasingly feasible in the mold industry due to selective laser melting (SLM) technology. Its surface created by SLM has surface roughness value, Ra of about 10 μm. Its rough surface can make an adverse effect on fatigue life of the mold. Abrasive flow machining (AFM) can be applied to finish the rough SLM internal surface because AFM media can flow and finish through its surface. Thus, in this study, we performed AFM on the non-heat treated and heat treated SLM internal surface with AFM media having different media viscosity and abrasive grain concentration. The SLM internal surface after AFM were characterized in terms of surface roughness value, Ra. The effects of AFM media parameters on surface roughness evolution after AFM are presented. Scanning electron microscopy (SEM) study on the SLM surfaces suggests possible wear mechanisms between abrasive grains and the SLM internal surface during AFM.