Study On New Metal Powder Materials By Selective Laser Sintering

Material research and development (R&D) and prototyping technology of new material were always one of the important research directions of Rapid Prototyping (RP) technology home and abroad. Because high-tech was strictly restricted from other countries overseas, commercial materials were not only expensive, but also only for users who buy their RP systems, and especially selective laser sintering was increasingly being the main development trend of RP technology, prototyping material research by selective laser singtering (SLS) was more important. Theory research on metallic nano-composite powder materials and experiment reseach on technics simulation optimization have especially important theoretical significance and practical value.Firstly, research status in quo of metal powder materials and nano-powder materials by SLS was reviewed. Theory model of coated metallic nano-composite powder materials based on low power laser (25/50W) by SLS was established. Difficulty and key technology of coated metallic nano-composite powder materials by SLS during preparation was analyzed. Nano second-phase dispersion in the metallic matrix inhibiting growth of matrix crystalline grain and density increased, by coating organic polymer on metallic nano-composite powder materials preventing from oxidation of nano powder materials in room temperature, by adding sintering assistant to improve mechanical property and sintering property of metallic nano-composite powder materials, volume increase from metal solid-state phase changes bridged interstise from degradation, and nano second-phase from reaction taken as grain boundary cavity filler were brought forward.Secondly, element prescription and preparation methods of coated Al-Fe-Ni alloy series metallic nano-composite powder materials by SLS were studied and optimized by orthogonal test method. Material prescription is 90Al-7Fe-3Ni and coating material is ethane vinyl acetate resin (EVA) was confirmed at last.Lastly, Influence factors of prototyping, such as powder property, laser power, scanning velocity, reaction atmosphere, spot size and preheating temperature, and sintering mechanism on nano-powder materials by SLS was analyzed. Prototyping technical parameters for coated Al-Fe-Ni alloy series metallic nano-composite powdermaterials by SLS that is laser power 25><80%, scanning velocity 3000mm/s, layer thickness 0.10mm and sintering space length 0.10mm were elementarily chosen after optimization, which laid a good foundation for subsequent research.The paper enriched and developed RP theory. Coated Al-Fe-Ni alloy series metallic nano-composite powder materials by SLS developed have high academic research value and broad applied prospects in aeronautics & astronautics, vehicle manufacturing, and ordnance industry etc.