Laser Based Selective Metal Powder Sintering: a feasibility study

Summary Selective Metal Powder Sintering is a ‘Material Accretion Manufacturing’ or ‘Rapid Prototyping’ process. It aims to be a manufacturing system to produce metallic parts with good mechanical properties. The present feasibility study addresses the basic binding mechanism to stuck powder particles together using a Nd:YAG laser. While conventional sintering occurs too slowly to be tackled by a scanning laser beam, preference went to liquid phase sintering. A Fe-Cu mixture gives promising results. Experiments reveal a large amount of parameters determining the process’ behaviour of liquid phase formation. Without precautions, the Fe powders tend to melt whilst Cu particles stay solid due to the high reflectivity of Cu for laser light. Three parameters seem to have important influence on the energy distribution between both metals: the particle diameter, reflectivity and mixture ratio. Simulations have been used to estimate settings for these parameters.