【作者】 焦光裴；

【导师】 赵振峰；

【作者基本信息】 郑州大学 ， 材料加工工程， 2013， 硕士

【摘要】 注塑制品因其优异的性价比得到越来越广泛的应用。但在注塑成型过程中,复杂的热力过程导致了残余应力的形成。对于注塑制品,残余应力的存在可能会导致制品出现细微裂纹、银纹等,使其光学性能下降,抗冲击强度降低等影响其使用性能。残余应力一般分为流动不均衡导致的流动残余应力和冷却不均匀导致的热残余应力两种。由于热残余应力比流动残余应力大一个数量级,所以注塑制品的残余应力主要是指制品冷却不均匀产生的热残余应力。本文以无定型聚合物聚碳酸酯(PC)为研究对象,进行实验分析。主要工作如下：1.选用无定形聚合物聚碳酸酯为实验材料进行注塑实验。先将注塑制品制备为样条,然后对不同工艺条件下的试样进行剥层,测量剥层后的变形情况。根据采集到的数据进行相关的力学分析,将变形量转化为曲率,代入推导出的残余应力计算公式,计算出PC制品厚度方向各层平均残余应力,并分析不同注射压力、保压压力和模具温度条件下对残余应力的影响。2.利用Moldflow对不同工艺条件下的残余应力进行分析,并根据模拟结果中厚度方向的残余应力计算各层平均残余应力,将模拟结果与计算结果进行对比分析。3.退火处理会使聚合物一些链段重新排列组合,使原有的部分应力得以松弛。在本文中对部分试样进行退火处理,分析相同工艺条件下残余应力的变化。更多还原

【Abstract】 Injection products are applied more and more widely for their high cost performance. But the complex heat history lead to the formation of residual stress in the injection molding process. The existence of residual stress will result in the craze, making the optical performance and impact strength of products decrease and affecting their application. The residual stress are generally caused by uneven flow and colling, called flow residual stress and thermal residual stress. Due to the thermal residual stress is one order of magnitude bigger than the flow residual stress, the thermal residual stress was studied in this paper.Based on the amorphous polycarbonate (PC) as the research object, main work is as follows:1. The PC splines were prepared by injection molding with different processing parameters, firstly. Then Layer removal method was carried out and the deformation was measured for all samples.With the mechanics analysis, the collected data of deformation were converted to curvature, then the values of residual stress along the thickness direction of PC samples were estimated using the derived residual stress formula. The effects of injection pressure, holding pressure and mold temperature on the residual stress were discussed respectively.2. The residual stresses under different processing parameters were calculated using Moldflow technology. The mean value of residual stress of each layer were estimated. Then the experimental results and simulation results were compared in the paper.3. The chain segment will rearrange during annealing and releasing part of residual stress. Annealing treatment was carried out on part of PC samples, and the effects of annealing on the residual stress were studied.更多还原