Titanium matrix composites (TMCs) have gained tremendous attention due to their excellent mechanical properties by combining the advantages of Ti6Al4V matrix and ceramic reinforcement. In current study, the selective laser melting (SLM) technique is applied to manufacture TiC/Ti6Al4V and Ti6Al4V. Systematic characterization and analysis are conducted to reveal and compare their process-structure-property relationships. The results reveal that the near fully dense parts could be manufactured by process optimization upon the systematic investigation on their densification behaviors. The addition of TiC effectively refines the matrix grain and changes the microstructures. The SLM-manufactured (SLM-ed) Ti6Al4V exhibits typical coarse columnar grains with ultrafine lamellar α+β microstructures distributed inside (average α-lath thickness: 282 nm). Nevertheless, the SLM-ed TMCs possess a peculiar molten pool morphology, in which the sub-columnar grains grow upward along the direction of the steepest temperature gradient. The acicular nanoscale TiC is dispersed inside the sub-columnar grains, while the chain-like TiC is distributed along the boundary. Meanwhile, an evolution process is proposed to describe the microstructure evolution of the SLM-ed TMCs. The interrelationships between energy density and resulting microstructures are also identified, based on which, strong and ductile Ti6Al4V specimens (tensile strength: 1390 MPa, elongation: 9.66%) and ultra-strong TMCs specimens (tensile strength: 1538 MPa) are manufactured. The strengthening effects are mainly attributed to the Hall-Petch strengthening and load-bearing transformation. Fracture analysis indicates that the failure of the SLM-ed Ti6Al4V is caused by the micro-voids nucleation and coalescence at the interface of α and β phases, whereas the premature fracture of the SLM-ed TMCs is originated from the chain-like TiC.

钛基复合材料 (TMC) 结合了 Ti6Al4V 基体和陶瓷增强体的优点，以其优异的机械性能而受到广泛关注。在目前的研究中，选择性激光熔化 (SLM) 技术被应用于制造 TiC/Ti6Al4V 和 Ti6Al4V。进行了系统的表征和分析，以揭示和比较它们的工艺-结构-性能关系。结果表明，在对其致密化行为进行系统研究后，可以通过工艺优化制造出接近完全致密的部件。TiC的加入有效地细化了基体晶粒，改变了显微组织。SLM 制造的 (SLM-ed) Ti6Al4V 具有典型的粗柱状晶粒，内部分布有超细层状 α+β 微观结构（平均 α 板条厚度：282 nm）。尽管如此，SLM-ed TMCs 具有特殊的熔池形态，其中子柱状晶粒沿着最陡的温度梯度方向向上生长。针状纳米级 TiC 分散在亚柱状晶内部，而链状 TiC 沿边界分布。同时，提出了一个演化过程来描述 SLM-ed TMC 的微观结构演化。还确定了能量密度与所得微观结构之间的相互关系，在此基础上制造了高强度和延展性的 Ti6Al4V 样品（抗拉强度：1390 MPa，伸长率：9.66%）和超强 TMCs 样品（抗拉强度：1538 MPa）。加固效果主要归因于Hall-Petch加固和承重转变。