中文摘要：

选用等规聚丙烯材料,基于正交表L_（25）（5~6）进行微注塑成型实验,制备厚度为0.5 mm的微注塑拉伸试样。采用偏光显微镜和广角X射线衍射仪对其形态结构进行表征,并分析工艺参数对微制品形态结构的影响规律和影响度。对微制品试样进行拉伸实验,分析工艺参数对其屈服应力、弹性模量和断裂伸长率的影响规律和重要度。结果表明,注射速度对微试样的形态结构和力学性能的影响最大;皮层厚度和皮层取向度随着注射速度的增大而减小;屈服应力随注射速度、熔体温度的增大而减小;熔体温度对弹性模量和断裂伸长率的影响较大,且弹性模量随着熔体温度的升高而减小,断裂伸长率随着熔体温度的升高而增大。

英文摘要：

Isotactic polypropylene was used as experimental material. The micro-injection molded experiments were conducted to mold the parts with the thickness of 0. 5 mm based on the orthogonal array L_（25）（5^6）. The morphology and micro structure were characterized by polarizing microscope and wide-angle X-ray diffraction,and the effect and significance of process parameters on the morphology and microstructure of micro-injection molded parts were analyzed. The tensile tests were conducted to analyze the effect and the significance of process parameters on yield stress,modulus and elongation at break. The results show that the injection speed has the largest influence on both the morphology and mechanical property. The thickness and the orientation degree of the skin layer decreases with the injection speed increasing. The yield stress decreases with the melt temperature and injection speed increasing. Melt temperature has bigger influence on modulus and elongation at break. With the increase of melt temperature,the modulus decreases and the elongation at break increases.