微观层状CNTs/Ni复合材料的可控制备与力学变形行为研究

Carbon nanotube (CNT) with unique structure and excellent physical and chemical properties has emerged as an ideal reinforcement for the preparation of composite materials. While CNTs/metal matrix composites is one of the most important research frontiers in the application of CNTs. Especially for the CNTs/metal matrix composites, how to realize regularly arranged controllable preparation for the CNTs in CNTs/metal composites is the hotspot and difficulty in the field of materials research. Based on the previous work, a new method for the preparation of CNTs/Ni composites with nanolaminated structure was proposed in this work. The project aims at improving the comprehensive properties of Ni matrix composites, solves the interface and dispersion problems between CNTs and Ni at the same time, designs and fabricates CNTs/Ni composites with nanolaminated structure with high strength, high toughness and high wear resistance. This research mainly focuses on the research of the deformation mechanisms and mechanical property of new nanolaminated composites in order to explored the intrinsic reciprocity for the mechanical properties with the parameters, such as interfacial effect and load transfer problem, effect of CNTs on the grain size of the matrix, and the influence between the CNTs/Ni interface and defects. The study can enrich the microstructure design of composite materials and the mechanism of composites strengthening and toughening, which has important academic value and application significance.

碳纳米管具有独特的结构和优异的理化特性，是制备复合材料的理想增强体，而碳纳米管金属基复合材料是碳纳米管应用的重点研究方向之一。对于碳纳米管金属基复合材料，如何实现碳纳米管规则排列的可控制备是材料研究领域的热点与难点。基于前期研究基础，本项目提出一种制备微观层状结构CNTs/Ni复合材料的新方法。该项目以提升Ni基复合材料综合性能为目标，以同时解决CNTs与Ni的界面和分散问题为途径，设计与制备高强度、高韧性及高耐磨性的层状CNTs/Ni复合材料。重点研究该层状复合材料的变形机理与力学性能特征，探索CNTs/Ni界面效应与承载转换，碳纳米管对基体晶粒尺度的影响，复合界面与缺陷之间的相互作用等参数对相关力学性能的影响及其内在的相互关系，建立相关基础理论模型，阐明层状CNTs/Ni复合材料的强韧化机理。本项目的研究可以丰富复合材料微观组织结构设计和强韧化理论，具有重要的学术价值与应用意义。

碳纳米管具有独特的结构和优异的理化特性，是制备复合材料的理想增强体。而碳纳米管金属基复合材料是碳纳米管应用的重点研究方向之一。对于碳纳米管金属基复合材料，如何实现碳纳米管规则排列的可控制备是材料研究领域的热点与难点。. 项目基于复合电沉积技术提出一种可控制备微观层状 CNTs/Ni 复合材料的新方法：首先把表面改性过的碳纳米管加入电沉积溶液，经过超声波震荡与磁性搅拌获得碳纳米管均匀分散的悬浮液，然后采用旋转电沉积设备进行复合电沉积。通过调整相关工艺参数，实现微观层状结构 CNTs/Ni 复合材料的可控制备，获得高强度高塑性的CNTs/Ni复合材料。研究碳纳米管酸化活化处理对表面微观缺陷及功能性官能团的影响；基于调整复合电沉积工艺参数，比如镀液内碳管含量、磁力搅拌、超声波搅拌、电流密度等，研究工艺参数对镀层内碳管含量的影响；研究该复合材料的变形机理与力学性能特征，探索CNTs/Ni界面效应与承载转换，CNTs对基体晶粒尺度的影响，复合界面与缺陷之间的相互作用等参数对力学性能的影响及其内在的相互关系；阐明该复合材料的CNTs/Ni界面、晶界和CNTs于基体内的分布密度共同作为增强因素的强韧化机理与变形机制，指出CNTs的引入可以增加Ni原子的形核点以及CNTs较小的间距可以阻碍镍晶粒的生长，即CNTs的加入细化基体晶粒尺度。此外，在形变过程中，CNTs/Ni界面产生形变孪晶或多重孪晶以协调界面处的应力集中，避免界面出现微观裂纹；CNTs/Ni界面处出现高密度的几何必需位错，引起统计存储能密度梯度，促使形变孪晶的产生。本项目的研究可以丰富复合材料微观组织结构设计与强韧化理论，具有重要的学术价值与应用意义。