Sintering M3/2 High Speed Steel Powder by DMLS Process
The Direct Metal Laser Sintering (DMLS) technology uses a mixture of metal powders with different melting points to build objects layer by layer, directly from the geometric digitalised information. This process allows the manufacturing of prototype and production tools. In this study, the M3/2 high speed steel powder blended with 20 wt.% Cu3P and 0.25 wt.% graphite was laser-sintered, using two scan speeds (100 and 200 mm/s), keeping constant both hatching (0.30mm between two consecutive lines) and laser power (180W). The powder was spread in uniform layers of about 20m over a steel plate (100x60x6mm). The laser beam scanned small areas (12x15mm) in a single direction (OX). The surface morphology of the laser-sintered material shows that all material melted, but for 200mm/s scan speed, strings are well defined. This is probably due to a lower level of energy supplied to the material. The microstructure of the sintered material was studied in the longitudinal and transverse sections, to evaluate the consolidation process and layer growth. The material showed porosity and cracks formed during the process.
Paula Maria Vilarinho
I. M. Martins et al., "Sintering M3/2 High Speed Steel Powder by DMLS Process", Materials Science Forum, Vols. 514-516, pp. 1506-1510, 2006