高强韧-高阻尼仿生叠层CNTs/Mg复合材料构建及其仿生结构效应研究

Mg matrix composites own low density and high damping, but its inverse relationship between strength and damping property obviously restricts the application of Mg matrix composites in lightweight, high-speed weapons and vehicles . Thus, this proposal plans to fabricate a bionic lamellar structure Mg matrix composites owning high mechanical properties and damping property through taking advantage of carbon nanotubes and lamellar structure effect of shell, which can solve the inverse relationship between mechanical properties and damping property of Mg matrix composites. Firstly, the applicant team develops a novel fabrication for bionic lamellar structure Al matrix composites by combining the electrophoretic deposition, spark plasma sintering and accumulative roll bonding. The dispersion mechanism and interface reaction of carbon nanotubes will be researched using SEM and TEM, and the formation mechanism for the lamellar structure will be researched too. Besides, the effects of the bionic lamellar structure on the local strain distribution and microstructure evolution will be researched by the in-situ tensile with digital image correlation and in-situ electron microscope technology. Based on above study, this proposal plans to establish the relationship between the fabrication, lamellar structure, microstructure, mechanical properties and damping property, and reveal the strengthening and damping property mechanism of the bionic lamellar structure Mg matrix composites. The proposal will also provide a theoretic basis and experimental data for the design and fabrication of metal matrix composites.

镁基复合材料的密度小，阻尼大，但是力学性能-阻尼性能的矛盾制约着其在轻量化、高速化武器装备、交通工具等领域的应用。本项目利用碳纳米管(CNTs)优异的性能和贝壳叠层结构效应，研发一种具有仿生叠层结构的高强韧-高阻尼的镁基复合材料，解决复合材料力学性能-阻尼性能的矛盾。申请团队结合CNTs的表面化学处理，电泳沉积、等离子放电烧结和热轧技术，开发一种新型仿生叠层结构CNTs/Mg复合材料制备方法，并研究仿生叠层结构的构建原理；利用SEM和TEM研究表面改性后CNTs的分散规律及其与镁基体的界面作用机制；结合DIC技术和SEM研究叠层结构参数对复合材料内局部应变分布和显微组织演变的影响规律；建立制备工艺-叠层结构-显微组织-力学和阻尼性能的关系，揭示仿生叠层结构效应机理，为新型镁基复合材料的设计及制备提供理论基础与试验依据。

镁基复合材料的高比强度、比刚度和良好阻尼性等优势，使其在航天、航空和汽车等领域具有广泛的应用前景。镁基复合材料的研究仍主要集中在追求增强体的高含量和均匀分布，如此仅提高了复合材料的强度，却牺牲了其韧性和阻尼性能，即传统镁基复合材料的强度和韧性、阻尼性能长期存在矛盾关系，显著地制约着镁基复合材料的应用。因此，迫切需要开发高强韧、高阻尼的镁基复合材料，适应工业发展对高强高阻尼材料日益增长的需求。本项目通过模仿贝壳叠层结构，采用CNTs表面化学处理+电泳沉积+SPS和热轧技术制备仿生叠层CNTs/Mg复合材料，利用CNTs超强的力学性能和优异的叠层结构效应，获得强韧性和阻尼性能的良好匹配。通过创新方法解决了CNTs均匀分散与界面控制等CNTs/Mg复合材料制备关键问题；调控并优化了CNTs/Mg 复合材料叠层结构参数，建立了叠层结构-显微组织-性能的关系，揭示了仿生叠层CNTs/Mg 复合材料的结构效应机制。为实现高强韧-高阻尼结构功能一体化的镁基复合材料的制备提供了理论基础与试验依据。