石墨烯/钛基复合材料的界面反应控制、微观组织和压缩性能

将Ti6Al4V（TC4）粉末与少层石墨烯（GR）粉末进行三维机械旋转混合，实现了GR在TC4球形粉末表面的均匀包覆，经放电等离子烧结(SPS)得到增强相呈三维网络状分布的GR/TC4复合材料。对不同的SPS烧结温度、保温时间、升温速率和轴向压力对GR与钛基体原位界面反应程度的影响进行了研究，并对界面处不同GR/TC4比例的网状结构复合材料的物相结构、显微组织及室温压缩性能进行了系统性的研究。结果表明，烧结温度和升温速率是影响GR与基体反应程度的主要因素，压力主要影响材料致密度，低温高压快速烧结可以降低GR与基体的反应程度，但高比例的GR残留并没有带来力学性能的大幅提升。对于0.25wt%的GR添加量，GR的反应比例约为70%~80%能得到更加良好的异质界面的结合，获得综合力学性能优异的GR/TC4协同增强的钛合金基复合材料。GR在钛合金基体中的三维网络状分布能调控钛基复合材料的强度与塑性的矛盾。 

Tailoring of interface reaction,microstructure and compressive properties of graphene reinforced titanium alloy matrix composites

Few-layered graphene reinforced titanium matrix composites (GR/TC4) with 3D network structures were fabricated through a 3D mixing machine and spark plasma sintering (SPS) technique. The effects of different sintering temperatures, holding time, heating rate and uniaxial pressure in the SPS on the in-situ interface reaction of GR with titanium matrix were studied. The phases, microstructure and compressive properties at room temperature of the network structured composites with different GR/TiC ratios were investigated systematically. Experimental results exhibite that the SPS temperature and heating rate are the key factors for determination of reaction ratio of the GR with matrix and the uniaxial pressure affects relative density of the composites. Low temperature, high pressure and fast sintering can inhibit the reaction between the GR and matrix. However, the composites with more residual GR do not show excellent mechanical properties. It is indicated that excellent compressive strength and ductility integrated mechanical properties are achieved with GR reaction ratio of 70%-80% in the 0.25wt% GR/TC4 composites, where the interface bonding is to an optimal state. The 3D network distribution of GR in the titanium alloy matrix can tailor the conflict between strength and ductility of the titanium matrix nanocomposites.