为了探究固溶处理过程中耐高温第二相对Al12Si合金微观组织及力学性能的影响，本工作采用选区激光熔化(SLM)工艺制备了AlCrCuFeNi高熵合金(HEA)改性Al12Si合金，结合后续的固溶处理实现了对Al12Si合金微观组织与力学性能的协同调控。重点研究了固溶处理过程中耐高温第二相对Al12Si合金微观组织和力学性能的调控机制。结果表明，打印态Al12Si试样具有由典型的初生α-Al和连续共晶Si组成的胞状组织；而HEA颗粒的加入使Al12Si-HEA试样打印态组织发生显著转变，由Al12Si试样中的共晶Si相转变成共晶Si + α-Al(Fe, Cr)Si相。固溶处理后，Al12Si试样中连续的胞状共晶组织解体，转变成在基体中弥散分布的颗粒状Si相。此外，随着固溶时间的延长，Si相由于发生Ostwald熟化而逐渐粗化，平均直径变大，同时数量密度降低。值得注意的是，α-Al(Fe, Cr)Si相能够阻塞Si元素在基体中的扩散通道，从而显著降低颗粒状Si相的粗化速率。力学性能测试表明，在所有固溶时间下，Al12Si-HEA试样均表现出比Al12Si试样更优异的综合性能。这可归结于经固溶处理后，Al12Si-HEA试样形成了双粒径原位增强颗粒的微观组织，即更为细小的微米级Si相和纳米级α-Al(Fe, Cr)Si相。这种独特的微观组织使得Al12Si-HEA试样在保持较高塑性(约14%)的同时，也具有优异的极限抗拉强度(311 MPa)。

Heat treatment has been widely shown to substantially influence the microstructure of selective laser melted Al alloys and composites, enabling precise tuning of their mechanical properties. While extensive research has addressed the optimization of selective laser melting (SLM) process parameters, alloy composition, reinforcement content, and strengthening mechanisms, comparatively limited attention has been paid to the evolution of microstructure and mechanical properties of selective laser melted Al alloys and their composites during heat treatment. A critical knowledge gap remains regarding the mechanisms by which secondary phase particles govern microstructural evolution and mechanical property modifications under thermal processing. To address this gap, an Al12Si alloy modified with an AlCrCuFeNi high-entropy alloy (HEA) was successfully fabricated via SLM. Subsequent solution treatment enabled synergistic control over the microstructure and mechanical properties of the Al12Si-HEA alloy. Comprehensive microstructural characterization and mechanical testing were conducted to systematically investigate the role of HEA particles in influencing microstructural evolution and mechanical behavior during solution treatment. The results showed that the as-built Al12Si alloy exhibited a microstructure composed of primary α-Al and continuous cellular eutectic Si. The addition of HEA particles significantly modified the microstructure, promoting the formation of Si + α-Al(Fe, Cr)Si phases instead of the continuous eutectic Si observed in the unmodified Al12Si alloy. Solution treatment dissolved the cellular eutectic structure, leading to fragmentation and spheroidization of Si into granular phases diffusely distributed within the matrix. With increasing solution treatment time, these Si phases gradually coarsened due to Ostwald ripening, resulting in larger average sizes and reduced number density. Notably, the α-Al(Fe, Cr)Si phases inhibited Si atom diffusion within the matrix, substantially slowing the coarsening rate of the granular Si phases. Under all solution treatment conditions, the Al12Si-HEA alloy exhibited superior performance compared with the Al12Si alloy. This enhancement is attributed to the formation of dual-sized in situ reinforced phases after solution treatment, comprising finer micron-sized Si particles and nano-sized α-Al(Fe, Cr)Si phases. This unique microstructure enabled the Al12Si-HEA alloy to achieve both high str-ength (ultimate tensile strength > 300 MPa) and appreciable plasticity (~14%).