PS/ABS复合粉末选择性激光烧结工艺参数的实验研究

针对选择性激光烧结件力学性能和尺寸精度差的问题,通过机械混合法制备了聚苯乙烯/丙烯腈-丁二烯-苯乙烯塑料(PS/ABS)的复合粉末。在预热温度85℃、8层网格支撑等条件下,采用单因素实验法研究激光功率、扫描速度、扫描间距和单层厚度对烧结件强度和相对误差的变化规律,并用正交试验对工艺参数进行优化。结果表明,烧结件的弯曲强度随着激光功率的增加而提高,随扫描速度、扫描间距和单层厚度的增加而降低。Z向尺寸相对误差随着激光功率的增加而增大,随着扫描速度、扫描间距和单层厚度的增加而减小;由极差分析可知,激光功率对PS/ABS烧结件弯曲强度和Z向尺寸相对误差的影响最大;最优的工艺参数组合为:激光功率30 W、扫描速度1 200 mm/s、扫描间距0.32 mm和单层厚度0.26 mm,此时烧结件的弯曲强度为7.85 MPa,Z向尺寸相对误差为1.30%。

Experimental Study on Process Parameters of PS/ABS Composite Powders Based on Selective Laser Sintering

The problems that the low mechanical strength and weak dimensional accuracy of sintered parts molded by selec-tive laser sintering (SLS) have been identified. Polystyrene/acrylonitrile butadiene styrene plastic (PS/ABS) composite powders were prepared by mechanical mixing. Under the condition of preheating temperature 85℃ and 8 layers of grid support,the changing regularity of the laser power,scanning speed,scanning interval and layer thickness on the strength and accuracy of the parts were studied by using single factor experiment. The process parameters were optimized by orthogonal experiment. The results show that the bending strength of the sintered parts is higher and higher with the increase of laser power,and lower and lower with the increase of greater scanning speed,scanning interval and layer thickness. The relative error of the Z-axis size increases with the increase of laser power,and decreases with the greater of the other three parameters. The range analysis results indicate that laser power's effect on the bending strength and Z-axis size relative error of the PS/ABS specimen is maximum. The optimal combinations of process parameters are laser power 30 W,scanning speed 1200 mm/s ,scanning interval 0.32 mm and layer thickness 0.26 mm,at this time,the bending strength of the sample is 7.85 MPa,the relative error of the Z-axis size is 1.30%.