碳纳米管增强镍基复合材料的强化机理及其作用机制

Carbon nanotubes can effectively reinforced nickel-based composites, but the carbon nanotubes can not effective combine with the matrix in preparing. Current studies showed that nickel can be effective deposited on the surface of carbon nanotubes, so that the better combination of coatings was obtained by electroless plating. Academic studies have established that the combination between carbon nanotubes and matrix can be improved by using specially-treated carbon nanotubes act as reinforced phase. Thus, this project is focus on the preparation of carbon-nanotube reinforced nickel-based bulk composites. The combination of powder metallurgy method and electroless plating method was used to enhance the dispersion of carbon nanotubes in matrix and the effective integration with metal matrix. In order to explore the strengthening mechanism of carbon nanotubes reinforced nickel-based bulk composites, the mechanism of infiltration of carbon nanotubes with nickel-metal interface in the electroless plating conditions will investigate by studying the microstructure of the composites. At the same time,the effect of the interface characteristics on high temperature mechanical properties of composites will also study. And the analysis of the interaction mechanism between carbon nanotubes and nickel metal matrix will perform. Apparent, the research on preparation and properties of high temperature Ni-based bulk composites will help us to enrich and develop the preparation technology and strengthening theory of high-temperature composites.

碳纳米管是镍基复合材料的有效增强体，存在的主要问题是碳纳米管与金属基体能否有效结合。化学镀可在碳纳米管表面覆盖一结合良好的镍层，而以镀镍碳纳米管作为金属基复合材料的增强体可以有效提高其与金属基体的结合。为此，本项目拟采用粉末冶金法与化学镀相结合的复合方法制备碳纳米管增强镍基块体复合材料，实现碳纳米管的良好分散以及与金属基体的有效结合。探讨在化学镀条件下碳纳米管与镍金属的界面浸润机理及碳纳米管增强镍基块体复合材料的强化机制，揭示复合材料组织结构和界面特征对复合材料高温性能的影响规律，探索碳纳米管与镍金属基体之间的相互作用机制和复合材料的载荷传递机制及失效机理，为高温镍基块体复合材料的制备和性能评价和发展高温复合材料的制备技术提供理论基础。

项目采用粉末冶金法与化学镀相结合的复合制备方法制备碳纳米管增强镍基块体复合材料，实现碳纳米管的较好分散以及与金属基体的结合，在复合材料的制备方法和技术上较好地综合了化学镀和粉末冶金两种方法的优点，为复合材的制备提供了新的实践。通过对碳纳米管增强镍基块体复合材料的制备工艺研究，确定了镍包覆碳纳米管的优化工艺，制备出了均匀镍包覆碳纳米管。开展了镍包覆碳纳米管与镍合金粉末的混合成型，研究了真空烧结和热等静压烧结对镍包覆碳纳米管增强镍基块体复合材料的烧结致密化的影响。开展了镍包覆碳纳米管增强镍基块体复合材料的拉伸、耐磨、高温氧化等性能测试，分析了复合材料的相关性能的影响规律，研究表明镍包覆碳纳米管的引入在较大程度上提高了基体材料的综合力学性能。从理论上分析和解释了镍包覆碳纳米管增强镍基块体复合材料的强化机理及镍包覆碳纳米管的作用机制，为高温镍基块体复合材料的性能评价和高性能复合材料的制备技术提供了理论和实践借鉴。