退火对微注射成型制品形态 结构与力学性能的影响-effect of annealing on morphology, structure and mechanical properties of microinjection molding products.docx

万方数据 摘要 通过拉伸测试、纳米压痕测试对微注射成型制品的力学性能进行测试，结 果发现制品的力学性能与制品各分层结构的力学性能都随着退火温度与时间的 变化发生规律性的变化，进一步分析发现，与宏观光学现象一样，都是内部结 构变化的外在表现，揭示了聚合物内部结构变化对其形态结构演变和力学性能 的影响。 关键词：微注射成型，微齿轮，退火，形貌，结晶结构，力学性能 2 目录 Abstract Micro injection molding is widely used in electronic communications, biomedical, precision instruments, aerospace, military and other areas, due to its wide use of materials, geometry shapes adaptability and high precision, low cost and high efficiency, continuous, automated production, the advantages of good physical and mechanical properties. This thesis supported by the doctoral fund optical-grade polymer microstructure evolution in low pressure injection molding and optical-mechanical properties of multi-scale (20124101110007), and did some research on micro injection molded isotactic polypropylene products before and after annealing. Using computer simulations to understand the process of melt flow in micro injection molding process under different temperature conditions, and observing different stripes in the annealed product in the polarized microscope morphology, combined with the crystallinity and hierarchical schematics to understand the mechanism of the stripes formation and its variation. Details shown below: CAE software Moldflow was used to simulate the flow behavior of the micro injection molding of isotactic polypropylene products (micro-gears and micro-tension spline) during filling, and compared with the experimental results. Due to change of the die size in the assembly process, uplift appeared in the spline when the ejector shorter. By filling simulation, a better understanding of the flow fluids in the filling process, melt front surface, providing the basis for later analysis of product structure and morphology. Micro injection molding of isotatic polypropylene products under different annealing process were observed by the polarized micro-scope and it was found with increasing annealing temperature, the number of stripes increase and the width of stri