Numerical Simulation Of The Process Of Manufacturing Metal Parts By Plasma Powder Deposition Manufacturing

Plasma Powder Deposition Manufacturing(PPDM) is a Rapid manufacturing(RM) technology, which melts metal powder by high-power Plasma heat source and shapes full density metal parts based on three-dimensional CAD model. Function gradient materials (FGM) parts can be manufactured by changing the powder composition in a specific location.Nowadays ,the key of PPDM technology is to get appropriate deposition process parameters.Therefore ,it is necessary to know the distribution and change of temperature by means of finite element analysis methods.Considering the characteristics of plasma deposition process, it is made to establish finite element model of the PPDM process and simulate the process on the thermal elastic-plasticity theory and the basis of the heat-transfer theory. Simplified discrete Gaussian heat source model is adopted, while Convective heat transfer boundary conditions are selected. It is made to simulate thermal stress by Newton-Raphson incremental iterative method based on linear theory of thermal stress. According to its characteristics, parts are mapped meshed with hexahedral element and substrates are free meshed with tetrahedron element. The Parametric finite element analysis program has been developed to simulate the temperature field and the stress field of PPDM in APDL language.The processes of manufacturing function gradient materials (FGM) fender mold and skin mold support part by plasma Powder Deposition Manufacturing(PPDM) were simulated by ANSYS software. The results showed that temperature field changed periodically. With the increase of average temperature, the temperature field tended to be uniform.Residual stress was mainly along the deposition path and the maximum residual stress exsited in the head and tail of the parts as will as location of maximum curvature. The effects of deposition process parameters on the formed parts were calculated and analyzed. The results showed that the ring path was better than"Z"path in the forming process.Also,preheating was a better choice than water cooling. An experiment was carried out to measure the temperature field. The results verified the correctness of the calculation results.