The Studying Of The Laser Sintering And Post-treatment Of The Polymer-coated Molybdenum Powder

It is the focus in the world using the Selective Laser Sintering method toproduce metal parts with the complicated contour. In this paper, the selectivelaser sintering of polymer-coated molybdenum powder and its post-treatment processesare studied. The major research contents and conclusion are as follows.In the experiments, the suitable raw materials have been chosen. The preparationmethods of polymer-coated molybdenum powder were developed on the basis of originalprocess. The low temperature was used to prepare polymer-coated molybdenum powder,which was suitable for selective laser sintering process. Large number of sinteringexperiments were conducted using rapid prototyping machine. The influence factorson quality of sintered were studied, such as laser power and scanning speed etc.Combining the orthogonal experiments, optimization craft parameter of laser sinterpolymer-coated molybdenum were gained. The main parameters include that the laserpower is 15W, the scanning speed is lOOOmm/s, the powder thickness is 0.10mm andthe average size of powder particle diameter is 35um. The prototyping parts werefabricated under the optimal process parameters. The prototyping parts werepost-treated in the vacuum stove and the best post-treatment process, thepre-sintering, the high temperature sintering and the copper infiltration are obtainedwith large number of experiments. The result of the high temperature sinteringand the metal infiltration were analyzed. The metal parts and molds were fabricatedsuccessfully. The tensile strength of the copper-infiltrated pre-sintering part is 450MPa, the elongation is 14% and the impact toughness is 14 KJ/m2. The tensile strengthof the copper-infiltrated high temperature sintering part is 480 MPa, the elongationis 12% and the impact toughness is 14 KJ/m~2.