金属-聚合物注射成形界面微结构强化机理及力学性能研究

As having the characteristics of high strength, small quality and easy forming complex structures, metal-polymer composite parts are receiving increasing attention in the field of aerospace, automotive manufacturing and communications. Based on the forming technology for the metal-polymer composite parts, a new method to manufacture these products is proposed in this project. By improving the temperature, microscopic structure of the metal surface, and the viscosity, pressure and other characteristics of the polymer melt, the metal-polymer composite parts can be directly manunfactured by injection method. Accordingly, in this project, the characteristics that the polymer melt flows on the metal alloy surface and the mechanism of the melt bonding with the metal alloy are studied. Firstly, the theory of micro-structure formed on the metal surface is studied and the influences of different types of structures on the interface performance are compared; Then, the influences of the microscale effect of the polymer melt such as the viscosity effect, surface tension effect and wall slip effect on the ability of the polymer chain infiltrated in the micro-structure are studied. Thirdly, the solidification process of the polymer melt on the interface is analyzed and the models for the melt solidifying and crystallizing process in microscale are established. In the end, the relationship between the injection parameters and the melt flow, wetting and crystallization behavior on the metal surface is discussed and the influences of the injection parameters on the tensile strength and fatigue strength are also studied. The results presented of the project could supply useful data for the engineering application of the polymer resin injection bonding with the matal alloy technology.

金属-聚合物复合高强件具有强度高、质量小、易成形复杂结构等优点，在航空航天、汽车制造、通讯等领域日益得到重视。围绕金属-聚合物复合件的成形理论与技术，本项目提出通过改善金属表面的温度、微观结构和聚合物成形时的黏度、压力等因素，利用注射工艺直接成形金属-聚合物复合高强件的方法。研究金属表面微纳结构的形成方法及不同微结构对金属-聚合物界面结合力学性能的对应关系；探讨微尺度下聚合物熔体的黏度效应、表面张力效应和壁面滑移等因素对高分子链段浸入金属表面微纳结构的能力和界面结合力学性能的影响规律；分析熔体在金属-聚合物界面的固化机理和结晶类型，揭示金属-聚合物界面微结构强化机理。研究注射条件与熔体流动、润湿/浸入、固化/结晶等行为的对应关系，建立工艺参数对金属-聚合物界面的拉伸强度、疲劳强度等力学性能的影响关系曲线。项目的研究结果可为金属-聚合物复合高强件的注射成形提供理论指导和基础工艺数据支撑。

金属—聚合物复合高强件具有强度高、质量小、易成形复杂结构等优点，在航空航天、汽车制造、通讯等领域日益得到重视。本项目围绕注射条件下聚合物熔体与金属表面相互作用机理展开研究，通过对铝合金分别进行表面喷砂、弱碱腐蚀、电化学阳极氧化处理等方法进行处理和表征（包括扫描电镜、激光共聚焦显微镜、X射线光电子能谱等仪器），研究了金属表面微纳结构的形成理论，建立了描述表面微纳结构如孔隙度、孔洞深度、孔径分布等参数的表征与控制方法；分别针对特定金属获取其最佳的具有可靠连接强度的纳米微孔结构，提高了金属与聚合物之间的亲和力。研究了微尺度效应与表面微纳结构特征对熔体流动的影响规律，借鉴宏观熔体充模流动的基本方程，针对微通道中熔体的流动特性，建立表征熔体与微通道特征尺寸关系的微尺度粘度模型，并构建了微尺度下熔体充填金属表面微纳结构的数学模型，实现了微尺度下熔体充填金属表面微纳结构的数值模拟，以此为依据，分析了聚合物熔体流动的微尺度效应对熔体充填过程和金属—聚合物界面结合力学性能的影响规律。研究了熔体温度、模具温度、注射压力和时间、注射速率、保压压力和时间等成形参数对熔体黏度、压力、温度等物理场量的影响关系和各物理场量变化对熔体流动、润湿/浸入、固化/结晶行为的影响关系；建立了工艺参数对金属—聚合物成形件的力学性能的影响关系，为金属与聚合物注射结成形的工艺设计和调试提供理论指导和基础工艺数据。