Polystyrene/carbon fiber (PS/CF) hybrid powder were prepared by mechanical mixing. Under the condition of ambient temperature 25℃,scanning interval 0.30 mm and scanning mode XYSTA and so on,the effects and the law of preheating temperature,laser power,scanning velocity and layer thickness on the dimensional precision of PS/CF hybrid powder sintering parts were studied by using single factor experiment and slective laser sintering process. The optimal combinations of process pa-rameters of sintered parts size accuracy are determined by orthogonal experiment and extreme difference analysis according to the principle of comprehensive balance method. The results show that the effect of laser power on dimensional precision in X direction of the specimen is maximum,and the preheating temperature is minimum. The effect of scanning speed on dimensional precision of the specimen's Y direction is maximum,and the layer thickness is minimal. The layer thickness to the Z direction dimensional precision of the specimen is maximum,and preheating temperature is minimum. The optimal combinations of process parameters are preheat-ing temperature 85℃,scanning speed 1 800 mm/s,laser power 30 W and layer thickness 0.22 mm. The dimensional accuracy of the PS/CF sintered parts in X,Y and Z directions are increased by 18.44%,30% and 40.84% respectively,compared with the pure PS sintered parts under the same process parameters.%以机械混合的方式制备了聚苯乙烯/碳纤维(PS/CF)混合粉末材料.在环境温度25℃、扫描间距0.30 mm和扫描方式XYSTA等条件下,采用选区激光烧结(SLS)工艺,通过单因素试验法分别研究了预热温度、激光功率、扫描速度及分层厚度对PS/CF混合粉末烧结件尺寸精度的影响及规律;根据综合平衡法原则通过正交试验和极差分析确定了烧结件尺寸精度的最佳工艺参数组合.结果表明,激光功率对PS/CF烧结件X向尺寸精度的影响最大,预热温度对其影响最小;扫描速度对Y向尺寸精度的影响最大,分层厚度对其影响最小;分层厚度对Z向尺寸精度的影响最大,预热温度对其影响最小.最佳工艺参数组合为:预热温度85℃,扫描速度1800 mm/s,激光功率30 W,分层厚度0.22 mm,此时PS/CF烧结件与同种工艺参数下的纯PS烧结件相比,X向、Y向和Z向的尺寸精度分别提高18.44%,30%和40.84%.
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