Ball-milled Ti/TiC composite particles (TiC nanoparticles assembled on Ti microparticles) were designed, prepared, and mixed with Al-Si-Mg powder to fabricate an Al-Si-Mg-Ti alloy with TiC nanoparticles (Al-Si-Mg-Ti/TiC) by selective laser melting (SLM). Microstructure features, solidification behavior, and mechanical properties were investigated, and the relationship among them was established. The SLM-manufactured Al-Si-Mg-Ti/TiC material exhibited fine equiaxed-shaped α(Al) grains with nanoscale Si₄Ti₅ phases and Mg segregation along the grain boundaries. This structure benefited from heterogeneous nucleation as well as the grain growth restriction capabilities of TiC nanoparticles on α(Al), fast diffusion of Ti in the superheated Al liquid, and high chemical activity of Ti to Si during solidification. Furthermore, Ti enrichment in some local areas of the high-temperature pool and the consequently intense Marangoni convection improved the wettability between TiC nanoparticles and liquid Al without the interfacial reaction. Consequently, the SLM-manufactured Al-Si-Mg-Ti/TiC showed a high ultimate tensile strength of up to 562 ± 7 MPa and an elongation of up to 8.8 % ± 1.3 % before fracture. These increased mechanical properties are attributed to the combined effect of grain refinement and Orowan and load-bearing strengthening mechanisms.

设计，制备球磨Ti / TiC复合颗粒（组装在Ti微粒上的TiC纳米颗粒），并与Al-Si-Mg粉末混合以制造具有TiC纳米颗粒（Al-Si-Mg的Al-Si-Mg-Ti合金） -Ti / TiC）通过选择性激光熔化（SLM）。研究了微结构特征，凝固行为和力学性能，并建立了它们之间的关系。用SLM制造的Al-Si-Mg-Ti / TiC材料显示出具有等尺寸的纳米Si ₄ Ti _5的细等轴状α（Al）晶粒相和镁沿晶界偏析。这种结构得益于异质成核以及TiC纳米颗粒对α（Al）的晶粒生长限制能力，Ti在过热Al液体中的快速扩散以及凝固过程中Ti对Si的高化学活性。此外，在高温熔池的一些局部区域富集了Ti，因此发生了强烈的Marangoni对流，提高了TiC纳米颗粒与液态Al之间的润湿性，而没有发生界面反应。因此，由SLM制造的Al-Si-Mg-Ti / TiC在断裂前显示出高达562±7 MPa的高极限拉伸强度和高达8.8％±1.3％的伸长率。这些增加的机械性能归因于晶粒细化和Orowan以及承重强化机制的综合作用。