铝基复合材料综合力学性能优异，可满足航空航天领域高性能结构材料的应用需求，但是铝基复合材料的 热处理工艺大多沿用基体材料的工艺，忽视了颗粒增强体与析出相的交互作用。 利用原位反应制备了不同TiB2颗粒含 量(0%、1%、2%和 3%，质量分数)的 TiB2 /Al-4.5Cu-1Mn-0.3Mg 复合材料，研究了 TiB2 颗粒含量对铝铜基复合材料微观 组织和力学性能的影响。 结果表明，随着TiB2颗粒含量的增加，铸态复合材料的晶粒由树枝晶逐渐转变为细小等 轴晶，T6 热处理所需的峰值固溶温度降低，固溶时间和时效时间均减少，析出相的数量和尺寸减小，材料的屈服 强度和弹性模量呈上升趋势， 伸长率有所下降。 T6态3TiB2 /Al-Cu-Mn-Mg屈服强度和抗拉强度最高， 分别达到了 467.4、505.3 MPa，相较基体合金提高了 36.9%和 14.4%。

Aluminium matrix composites have remarkable mechanical properties that can satisfy the application requirements of high-performance structural materials in the aerospace field. However, the heat treatment process of aluminium matrix composites mostly follows the process of matrix materials, ignoring the interaction between particle reinforcement and the precipitated phase. In this paper, TiB2 /Al-4.5Cu-1Mn-0.3Mg composites with different TiB2 particle contents (0 wt.%, 1 wt.%, 2 wt.%, and 3 wt.%) were prepared via in situ reactions, and the effects of the TiB2 particle content on the microstructure and mechanical properties of the aluminium-copper matrix composites were investigated. The results show that with increasing TiB2 particle content, the grains of the as-cast composites gradually transform from dendritic crystals to fine isometric crystals. Concurrently, the peak solution temperature required for T6 heat treatment decreases as the solution time and aging time decrease. The quantity and size of the precipitated phase decrease, and the yield strength and elastic modulus of the materials increase, whereas the elongation decreases. Notably, the 3TiB2 /Al-Cu-Mn-Mg composite after T6 treatment has the highest yield strength (467.4 MPa) and ultimate tensile strength (505.3 MPa), surpassing those of the base alloy by 36.9% and 14.4%, respectively.