Direct laser sintering for rapid prototyping of complex shaped parts of steel

At Fraunhofer IWS in Dresden, the technology of direct generating of comple x-shaped parts from high melting metals has been developed in the last year s. It sues the short-time laser liquid-phase sintering of composite powders . Previous experiences have been extended on alloyed structural steel 17 Cr NiMo 6 heat treating steel 42 CrMo 4 and hot working steel X38 CrMoV 5 1. T he sintered parts deviated from the CAD-data no more than 0.1 mm the surfac e roughness R-Z was mostly < 0.05 mm. The relative density was in the area 60-70% according to the process parameters. In contrast to low melting mate rials, considerable increase of hardness and wear resistance were found. In order to increase density and strength, experiments of thermal and chemica l infiltrating the porous sintered parts were done with the result that up to 99% can be filled by material.