CNTs/SiCp混杂增强镁基复合材料的界面行为及强韧化机制研究

The key factors limiting the application and development of magnesium matrix composites are their comparatively low strength and poor ductility. In present project, applying a novel idea of CNTs/SiCp hybrid reinforced magnesium matrix composites, scientific and reasonable components are designed to exhibit the interface effect of CNTs, size effects of nano-phase hybrid reinforcements and shape effect of CNTs. It is aimed to develop a novel type of magnesium matrix composites with high strength and high stiffness as well as good ductility. First, using a CNTs pre-dispersion assisted ultrasonic vibration method, high-efficiency process parameters are employed to obtain the acceptable as-cast composites. The dispersion mechanisms of nano-phase hybrid reinforcements will be revealed. Second, chemical affinity strong elements are used to adjust the interface between CNTs and matrix. It is aimed to exhibit the interface effect of 1-D nano.materials. At last, the size effects of nano-phase hybrid reinforcements and shape effect of CNTs will are studied. The effects of CNTs and nano SiCp on microstructure and mechanical properties of matrix will are clarified in order to reveal the strengthening mechanism of composites. The above researches will provide a theoretic guide and experimental basis for design, fabrication and application of magnesium matrix composites with low cost and high properties.

相对低的强度和差的韧性是制约镁基复合材料应用及发展的关键因素。鉴于此，本项目基于碳纳米管（CNTs）和纳米碳化硅颗粒（SiCp）混杂增强镁基复合材料的新思路，通过科学合理地组分设计，充分发挥CNTs的界面效应、纳米相混杂增强体特有的尺寸效应与CNTs的形状效应，研制一种兼备有高强度、高刚度及良好韧性的新型镁基复合材料。首先，将CNTs预分散与超声波分散法相结合，探索一种高效的制备工艺，获得合格的铸态复合材料，阐明纳米相混杂增强体在复合材料内的分布规律及其机理。其次，使用化学亲和力强的元素对CNTs与基体界面进行优化，充分发挥CNTs作为一维材料特有的界面强化效应。最后，通过研究纳米相混杂增强体的尺寸效应和CNTs的形状效应，探究纳米相混杂增强体对复合材料组织性能的影响规律，揭示复合材料的强韧化机制。这将为低成本且高性能镁基复合材料的设计和应用提供重要的理论支撑与实验依据。

相对低的强度和差的韧性是制约镁基复合材料应用及发展的关键因素。本项目基于碳纳米管（CNTs）和纳米碳化硅颗粒（SiCp）混杂增强镁基复合材料的新思路，通过科学合理地组分设计，研制了一种兼备有高强度、高刚度及良好韧性的铸造镁基复合材料。首先，将CNTs预分散与球磨分散法相结合，获得了合格的铸态复合材料，阐明了纳米相混杂增强体在复合材料内的分布规律。其次，使用化学亲和力强的元素对CNTs与基体界面进行调控，充分发挥CNTs作为一维材料特有的界面强化效应。最后，通过研究纳米相混杂增强体的尺寸效应和CNTs的形状效应，探究纳米相混杂增强体对复合材料组织性能的影响规律，揭示复合材料的强韧化机制。这将为低成本且高性能镁基复合材料的设计和应用提供重要的理论支撑与实验依据。