PS/PMMA复合粉末选择性激光烧结成型精度工艺参数的研究

Study on Process Parameters of Forming Precision of PS/PMMA Composite Powder by Selective Laser Sintering

针对聚苯乙烯(PS)粉末在激光烧结成型过程中出现的成型件精度不足的问题,通过机械混合方式制备PS/聚甲基丙烯酸甲酯(PMMA)复合粉末,研究成型件在激光功率30W、预热温度95℃条件下,填充扫描速度、分层厚度及激光扫描间距对其长(X)、宽(Y)、高(Z)三个方向上尺寸精度变化的影响。首先采用单因素实验确定了三种工艺参数范围,再通过多因素正交实验对影响成型精度的工艺参数进行优化,得出烧结过程中的最优参数,以提高PS/PMMA复合粉末的激光烧结精度。结果表明,分层厚度对Z向成型精度影响最大,其次为扫描速度和扫描间距,分层厚度0.22mm、扫描速度2600mm/s、扫描间距0.32mm为最优参数,实验最终将试验件误差控制在0.34%。

Aiming at the problem of insufficient precision of polystyrene(PS)powder in laser sintering molding,PS/polymethyl methacrylate(PMMA)composite powder was prepared by mechanical mixing method.Under the condition of 30 W laser power and 95 ℃ preheat temperature,the effects of filling the scanning speed,layer thickness and laser scanning interval on the variation of dimensional accuracy of length(X),width(Y)and height(Z)were studied.In order to improve the laser sintering precision of PS/PMMA composite powder,the single factor experiment was used to determine the range of three process parameters,and then the multi-factor orthogonal experiment was used to optimize the process parameters affecting the molding precision and obtain the optimal parameters in the sintering process.The experimental results show that the layer thickness has the greatest influence on the forming precision of Z,followed by scanning speed and scanning interval.When the layering thickness is 0.22 mm,scanning speed is 2 600 mm/s,scanning spacing is 0.32 mm,the optimal parameters could be obtained.Finally the test error could be controlled at 0.34%.