【摘要】 具有低温固化高温使用特点的复合材料工装预浸料，是制造航空航天高精度复合材料成型工装极具潜力的材料之一。为实现其低成本、高精度成型，模具用预浸料一般采用更为复杂的低温预固化和高温后固化组成的2步工艺。模具成型固化应力不仅影响模具初始型面精度，而且在模具热循环使用过程中还可能产生应力松弛，进一步引起模具型面精度变化，进而影响零件成型精度。本文针对碳纤维增强复合材料模具凹凸复杂型面特征，通过试验研究了固化成型阶段和热循环使用过程中模具型面精度变化规律及影响因素。试验结果表明：成型阶段的固化应力及其在使用过程中的应力松弛行为是造成模具型面精度变化的主要因素，且型面偏差随热循环使用周期的增加而逐渐趋于稳定；成型阶段，模具型面偏差主要来源于由热膨胀不匹配、树脂固化收缩及金属母模作用诱导的固化应力，而使用阶段，固化残余应力的松弛行为是引起模具型面偏差的主要原因。研究结果能够帮助理解复合材料模具结构稳定性变化，同时，对于降低复合材料模具制造成本、提高使用寿命，实现复杂高精度复合材料构件的精确制造具有重要意义。更多还原

【Abstract】 Tooling composites prepreg cured at low temperatures and used in high temperature is one of the most promising materials for forming composite tools to manufacture high-precision composite structures in the aerospace field. Tooling composites prepreg utilizes a specially designed two-step method that consists of lowtemperature procuring and high-temperature post-curing in order to realize its low cost and high precision manufacture. The curing stress induced in composite tool manufacturing not only affects the accuracy of the initial tool profile, but may produce stress relaxation in the process of thermal recycling, which further causes the change of tool profile accuracy, and then affects the accuracy of components manufacturing. In this paper, the variation rules and influencing factors of profile accuracy of the complex profile characteristics of carbon fiber reinforced composite tools during solidification and thermal recycling were studied by experiments. The results show that the curing stress in the manufacturing process and the stress relaxation in the process of thermal recycling are the main factors that cause the variation of tool profile accuracy, and the profile deviation tends to be stable with the increase of the number of thermal recycling. Subsequent investigation reveals that the primary causes of the tool profile deviation during the manufacturing process are the interaction between the master mold and the composites tool, resin curing shrinkage,and thermal expansion mismatch-induced curing stress. In contrast, the primary cause of the mold surface deviation during the use stage is the relaxation behavior of the residual curing stress. The research results can help to understand the changes in the structural stability of composite tools. Meanwhile, it is of great significance to reduce the manufacturing cost of composite tools, improving the service life of composite tools and realizing the precise manufacturing of complex and high-precision composite components.更多还原