Prediction Of Processing Parameters For Selective Laser Sintering Of Polystyrene Powder

Aiming at the problems of high experimental cost,low applicability and long time-consuming in the process parameter optimization experiment of the selective laser sintering(SLS),the optimum parameters of the SLS polystyrene(PS)and its composites were analyzed and predicted by the finite element analysis software based on the principle of the SLS process in this study.First of all,based on the forming process and principle of the SLS process,a sintering simulation model of SLS process was established by using the finite element analysis software ANSYS based on the three-dimensional heat transfer model.The physical properties of the PS,PS/CF and PS/PE powders were measured respectively for the needs of real model and sintering experiments.Secondly,the influence of the process parameters on forming quality was analyzed comprehensively.The bending strength and forming precision of the forming parts were taken as the measure indexes,laser power and scanning distance were taken as the simulation analysis and prediction objects.Taking PS selective laser sintering process as an example,ANSYS simulation software was used to simulate and analyze the distribution of temperature field inside the powder during the fabrication process.According to the forming quality of the SLS process,the temperature field inside the powder was simulated and analyzed.The optimum temperature distribution requirement for the optimum time was deduced theoretically to predict the optimum laser power and scanning distance of the PS powder using SLS,and its validity was verified and analyzed by the sintering experiments.Finally,The optimum laser power and scanning spacing of the PS/CF and PS/PE composites were predicted and analyzed by simulation analysis and prediction method,and corresponding sintering experiments were carried out to verify the applicability of this method for the modified PS composites.The optimum laser power and scanning spacing in the sintering experiments of the PS powder were obtained by the simulation analysis and prediction method,and the investment casting process was chosen.In order to verify the coincidence between the simulation analysis and prediction results of the SLS forming process parameters and the actual industrial application values,large-scale sintering experiments of casting prototype were carried out.This thesis provides a novel idea for the prediction of the SLS process parameters,and provides a references and new idea for the industrial application of the PS and the modified PS composites in the field of SLS.