Forming Simulation and Experimental Verification of Combined Formation of Selective Laser Sintering and Cold Isostatic Pressing

Selective laser sintering (SLS) could manufacture complex parts rapidly which, however, have high porosity and low intensity. While the parts made by cold isostatic pressing have advantages of uniform structure without composition segregation, high-dimension precision and high density. However, it could not form high complex parts because of the difficulties in manufacturing bag. A combination of SLS and cold isostatic pressing is expected to use the advantages of the two methods and is an efficient way to make complicated parts rapidly. After SLS and cold isostatic pressing, dimensions of parts decrease and relative density increases. To predict final dimensions and density, the finite element simulations are performed for cold isostatic pressing. The results show the parts made from ball shape powder contract symmetrically. The simulation results agree with the achieved geometries within 4%. Comparisons are made with that parts made from irregular powder. The SEM pictures after SLS are also showed. This has an important indication to process of SLS and cold isostatic pressing forming.