Experimental Investigation of Maraging Steel Structure Obtained by Powder Bed Fusion Process with Milling Process

Abstract

This research aimed to examine the additive manufacturing process based on the observation of the sintered maraging steel manufactured by the powder bed fusion method. A combined processing of metal laser sintering with high speed milling was used for manufacturing of the sintered objects. The sintered workpiece was manufactured by recycled maraging steel powder. An equiaxial crystal was observed from the outer periphery to the center in the melt pool. The hardness in the height direction of the sintered workpiece was measured, which was approximately 370 to 400 HV, but only the top surface was 320 to 340 HV. As a result of observing the structure in the sintered workpiece, round like and horned like shaped contamination that were different from the solidification structure of the maraging steel was confirmed. These contaminations were confirmed to be TiO2 and TiN based on the analysis by EDX, and it was estimated to originate from the metal powder and the coating layer of the cutting tool.