Preparation of Mo/Cu composites by SLS method andits post-treatment techniques
(1.School of Materials Science and Engineering,North University of China, Taiyuan 030051, China2.Department of Science and Technology, China North Industries Group Corporation, Beijing 100083, China)
Abstract: A multi-component polymer-coated molybdenum powder was chosen for selective laser sintering(SLS). The powder was prepared by coating polymer on Mo particles and frozen by grinding techniques. The laser sintering activities and sound densification response were obtained by optimizing the process parameters. The post-treatment process of SLS samples was developed, which was high temperature sintering Mo framework combined with Cu impregnation. Then, the Mo/Cu composites are gained. The microstructure evolution of post-treatment samples was investigated by scanning electron microscopy. Mo grains frequently string together. The microstructural characterization of Mo/Cu composites is homogeneous compound structure of adhesive phase Cu linked with Mo grains. There is little ellipsoidal Mo grains singly existing around Cu phase. Between Mo grains and Cu zone, there is a medium changing zone with width of 10？20 nm. Post-treatment mechanism is Mo framework sintering of solid phase and Cu impregnation of melting/solidification. The mechanical and thermal properties concluding tensile strength, elastic modulus, elongation and linear expansion of Mo/Cu composites were studied.
Key words: polymer-coated Mo powder; selective laser sintering; high temperature sintering; copper impregnation