| Summary: | 碩士 === 國立成功大學 === 機械工程學系 === 104 === This study focused on selective laser sintering (SLS) at the conditions with preheating and shielding gas. Experimentally with the sintering parameters for 304L stainless steel powder, the specimen surface microstructure and porosity were observed. It is going to find the optimum parameters for multilayer stack.
The sintering experiments were made with Q-switched Nd-YAG laser (a wavelength of 1064nm) in a ratio of 4: 1 (stainless steel to copper). The laser power, scanning speed, scanning space and preset powder thickness were selected as experimental parameters to investigate the relationship between morphology and porosity in laser sintering. It could find the warpage and cracking phenomenon. With the preheating the powder to reduce warpage, the overlap rate is a critical parameter.
Numerical analysis with finite element analysis software –ANSYS(APDL) to simulate the moving heat source in a non-linear transient model based on sequentially coupled thermo-mechanical field analysis, the thermal stress, deformation caused by different scanning parameters were simulated. Finally, the simulation results were compared with experimental results.
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