In this study, in situ-formed TiC/TC4 alloy nanocomposites were fabricated using the selective laser melting (SLM) process with TC4 and graphene nanoplates (GNPs) powders, and the deformation strengthening mechanism of the Ti matrix reinforced with TiC nanoparticles was investigated. The results from microstructure observation and molecular dynamics simulations revealed that the appearance of nanoscale TiC reinforcement favoured the formation of deformation twinning, which promoted that the atoms of the TiC/TC4 alloy nanocomposites maintained an orderly arrangement during deformation. Further, a dual strengthening mechanism of that the severe lattice distortion at the interface formed by different orientations and the deformation twinning suppressed the movement of the dislocation has been put forward to describe the occurring of dislocation pinning effects. All these findings provide a feasible perspective to strengthen mechanical performance by addressing the long-standing issue in the SLM of TC4 alloy nanocomposites.

在本研究中，原位使用选择性激光熔化 (SLM) 工艺使用 TC4 和石墨烯纳米片 (GNPs) 粉末制备了成形的 TiC/TC4 合金纳米复合材料，并研究了用 TiC 纳米颗粒增强的 Ti 基体的变形强化机制。微观结构观察和分子动力学模拟结果表明，纳米级TiC增强体的出现有利于形变孪晶的形成，促进了TiC/TC4合金纳米复合材料的原子在形变过程中保持有序排列。进一步提出了不同取向形成的界面处严重的晶格畸变和形变孪晶抑制位错运动的双重强化机制来描述位错钉扎效应的发生。