In order to refine the microstructure and improve the performance of direct energy deposited (DED) additively manufactured Al–Mg–Sc–Zr alloy, TiC-modified Al–Mg–Sc–Zr composites were prepared by DED and the effect of TiC content on the microstructure and performance was studied. In the absence of TiC particle, the microstructure of Al–Mg–Sc–Zr alloy prepared by DED consisted of fine grains with average size of 8.36 μm, and well-dispersed nano-Al₃(Sc,Zr) particles inside the grains and Mg₂Si phase along the grain boundaries. With the addition of 1 wt% TiC, the microstructure of TiC/Al–Mg–Sc–Zr prepared by DED became finer apparently compared with that without TiC; while the further increase of TiC content to 3 wt%, the microstructure of TiC/Al–Mg–Sc–Zr prepared by DED became coarser with appearance of a new kind of needle-like (Ti,Zr)₅Si₃ phase. Also, the addition of TiC decreased the porosity of Al–Mg–Sc–Zr prepared by DED. Simultaneously, after the addition of TiC, the tensile strength increased from 283.25 MPa to 344.98–361.51 MPa, and the elongation increased from 3.61% to 9.58–14.10%. The potential mechanism of the microstructure evolution and strength improvement was discussed. This research will provide new insights into the available metal matrix composites by laser additive manufacturing (LAM).

为了细化直接能量沉积 (DED) 增材制造的 Al-Mg-Sc-Zr 合金的显微组织和性能，通过 DED 制备了 TiC 改性的 Al-Mg-Sc-Zr 复合材料，并研究了 TiC 含量对研究了微观结构和性能。在没有 TiC 颗粒的情况下，DED 制备的 Al-Mg-Sc-Zr 合金的微观结构由平均尺寸为 8.36 μm 的细晶粒和在晶粒内分散良好的纳米 Al ₃ (Sc,Zr) 颗粒和镁₂沿晶界的 Si 相。添加 1 wt% TiC 后，DED 制备的 TiC/Al-Mg-Sc-Zr 的显微组织比未添加 TiC 时明显更细；当 TiC 含量进一步增加到 3 wt% 时，DED 制备的 TiC/Al-Mg-Sc-Zr 的微观结构变得更粗，并出现了一种新型针状 (Ti,Zr) ₅ Si ₃阶段。此外，TiC 的添加降低了 DED 制备的 Al-Mg-Sc-Zr 的孔隙率。同时，加入TiC后，拉伸强度从283.25 MPa提高到344.98-361.51 MPa，伸长率从3.61%提高到9.58-14.10%。讨论了显微组织演变和强度提高的潜在机制。这项研究将为激光增材制造 (LAM) 的可用金属基复合材料提供新的见解。