Sintering zone prediction in direct metal laser sintering by finite element method
(1.School of Manufacture Science and Engineering, Sichuan University, Chengdu 610065, China2.Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang 621900, China)
Abstract: A three-dimensional finite element thermal model in direct metal laser sintering(DMLS) including the effect of powder-to-solid transition were established to predict sintering zone, which benefited the determination of suitable process parameters in DMLS. The nonlinear transient model of the metals thermal conductivity for powder-to-solid transition was developed. The model uses solid thermal properties of material in liquid-phase zone, transitional ones in sintering or sintered zone and powder ones in unsintered zones of powder bed to predict, respectively. Sintering zone boundary was estimated by maximum temperature history profile. Experiments were carried out using multi-component Cu-based metal powder. Compared experimental and predicted results, the mean error of sintering depth and width are 7.8% and 14.4%, respectively, which confirms the accuracy of the FEM prediction.
Key words: direct metal laser sintering； finite element method； thermal model； numerical simulation； sintering zone prediction