Abstract Discontinuously reinforced 3D network structured Ti6Al4V (TC4) matrix composites with multilayer graphene (MLG) were fabricated via 3D dynamic mixing and spark plasma sintering (SPS) at high pressures (250–500 MPa). The interface microstructure, mechanical properties and strengthening mechanisms were systematically studied with various MLG contents. Experimental results exhibited that MLG can be relative uniformly dispersed onto the surface of TC4 powders by the 3D dynamic mixing method, SPS parameter of 700 °C-500 MPa caused weak interface bonding between MLG and Ti matrix, and 900 °C-250 MPa was determined as the optimal sintering condition. Appropriate ratio of in-situ generated TiC phase with approximately 30 vol% retained MLG at the interface was beneficial to the interface bonding. The compressive strength of the composites was remarkably enhanced with excellent compressive ductility. Superior mechanical properties with the highest strengthening efficiency (65.5%) and tensile strength, acceptable tensile ductility (9.0%) and higher Vickers microhardness were achieved in the 0.15 wt% MLG composites due to its better interface microstructure. The network interface strengthening mechanism by the TiC phase and residue MLG is proposed to be the dominant mechanism with a few contributions from C solid solution and fine-grain strengthening.

中文翻译：

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具有网络结构的多层石墨烯增强钛合金基纳米复合材料的界面微观结构和强化机制

摘要 具有多层石墨烯 (MLG) 的非连续增强 3D 网络结构 Ti6Al4V (TC4) 基复合材料是通过 3D 动态混合和高压 (250-500 MPa) 放电等离子体烧结 (SPS) 制造的。系统研究了不同 MLG 含量的界面微观结构、力学性能和强化机制。实验结果表明，通过 3D 动态混合方法，MLG 可以相对均匀地分散在 TC4 粉末表面，700 °C-500 MPa 的 SPS 参数导致 MLG 与 Ti 基体之间的界面结合较弱，而 900 °C-250 MPa确定为最佳烧结条件。适当比例的原位生成的 TiC 相与约 30 vol% 保留在界面处的 MLG 有利于界面键合。复合材料的抗压强度显着提高，具有优异的抗压延展性。由于其更好的界面微观结构，0.15 wt% MLG 复合材料具有优异的机械性能，具有最高的强化效率 (65.5%) 和拉伸强度、可接受的拉伸延展性 (9.0%) 和更高的维氏显微硬度。TiC 相和残留物 MLG 的网络界面强化机制被认为是主要机制，C 固溶体和细晶强化的贡献很少。15 wt% MLG 复合材料由于其更好的界面微观结构。TiC 相和残留物 MLG 的网络界面强化机制被认为是主要机制，C 固溶体和细晶强化的贡献很少。15 wt% MLG 复合材料由于其更好的界面微观结构。TiC 相和残留物 MLG 的网络界面强化机制被认为是主要机制，C 固溶体和细晶强化的贡献很少。