3D finite element model of nylon 6/Cu composite powder is established for the selective laser sintering (SLS) process, and the factors of radiation, convection and thermal physical parameters highly nonlinear with temperature are taken into account. The load of moving heat source at different time and locations are carried out by the technique of "element birth/death" with ANSYS Parametric Design Language (APDL), and the "dynamic" distribution of thermal stress field in SLS is simulated with the method of indirect thermal-stress coupling. The results show that the thermal stress in the nearby zone of pool and the junction interface between part and substrate are high, and the maximum stress is decreasing with the going of sintering. The reasons for the production and distribution of thermal stress are studied, and the effective measure to avoid warping for sintered parts is proposed. The simulation results are consistent with that of experiment.
Zhang Jian, Li Deying, Zhao Longzhi, Xiong Guangyao Key Laboratory of Ministry of Education for Conveyance and Equipment, East China Jiaotong University, Nanchang 330013, China
