The effects of solid solution treatment on microstructure and mechanical properties of SiC_p/2024 Al matrix composite fabricated via powder thixoforming were investigated, as well as those of 2024 matrix alloy for comparison. The results indicate that the solution progress of the composite is more hysteretic than that of the alloy due to the obstacle role of SiC_p to eutectic dissolution and grain coarsening. Interestingly, interface reactions of SiC_p/2024Al, similar to those during fabrication, continuously occur during the solution treatment. Simultaneously, two constituents of the interface reaction layer, Al₂Cu and MgAl₂O₄ phases, change from the original agglomerated distribution to uniform distribution and finally to segregated form again accompanied by coarsening and phase transformation of Al₂Cu into Al₂CuMg. Such changes of the reaction layer significantly affect the interface debonding of SiC_p/matrix or SiC_p cracking during tensile test, and thus, the fracture regime and mechanical properties of the composite. The achieved modified shear-lag strengthening model by considering the strengthening effect of eutectic compounds can well interpret the strengthening mechanisms of these two materials, especially the variations of each strengthening mechanism contribution with solution time and the corresponding differences between these two materials.

研究了固溶处理对粉末触变成型制备的SiC _p / 2024 Al基复合材料的组织和力学性能的影响，并与2024基体合金进行了比较。结果表明，由于SiCp_对共晶溶解和晶粒粗化的阻碍作用，复合材料的固溶过程比合金的固溶过程更滞后。有趣的是，SiC _p / 2024Al的界面反应类似于制造过程中的界面反应，在固溶处理过程中连续发生。同时，界面反应层的两种成分为Al ₂ Cu和MgAl ₂ O _4。相的变化，从最初的团聚分布变为均匀分布，最后变为偏析形式，同时伴随着Al ₂ Cu的粗化和相变而转变为Al ₂ CuMg。反应层的这种变化显着影响拉伸试验过程中SiC _p /基体的界面剥离或SiC _p裂纹，从而影响复合材料的断裂状态和力学性能。考虑共晶化合物的强化效果而获得的改进的剪力-滞后强化模型可以很好地解释这两种材料的强化机理，尤其是每种强化机理的贡献随固溶时间的变化以及这两种材料之间的相应差异。