A heat-treatable Al-3.5Cu-1.5Mg-1Si alloy is successfully fabricated by selective laser melting and is investigated concerning microstructures and mechanical properties. The as-prepared samples show a fine-granular microstructure in the individual melt pool of the tracks and a coarse-granular microstructure in the areas between the tracks. After T6 heat treatment, the grain size of the specimens increases slightly and the Q phase formed in the as-prepared specimens transforms to Al₂Cu(Mg), Mg₂Si, and Al_xMn_y. All Al-Cu-Mg-Si specimens before and after heat treatment fracture around the defects that were generated during processing and show intergranular fracture along columnar grains upon tensile quasi-static loading. The as-fabricated samples exhibit a yield strength (YS) of 223 ± 4 MPa and an ultimate tensile strength (UTS) of 366 ± 7 MPa with an elongation of 5.3 ± 0.3%. After T6 heat treatment, the YS and UTS increase dramatically to 368 ± 6 MPa and 455 ± 10 MPa due to the formation of nano-sized Al₂Cu(Mg) precipitates, while the ductility remains fairly similar.

通过选择性激光熔化成功地制备了可热处理的Al-3.5Cu-1.5Mg-1Si合金，并对其微观结构和力学性能进行了研究。所制备的样品在轨道的各个熔池中显示出细颗粒的微观结构，并且在轨道之间的区域中显示出了粗颗粒的微观结构。经过T6热处理后，试样的晶粒尺寸略有增加，并且在制备的试样中形成的Q相转变为Al ₂ Cu（Mg），Mg ₂ Si和Al _x Mn _y。热处理前后的所有Al-Cu-Mg-Si试样都围绕加工过程中产生的缺陷断裂，并在拉伸准静态载荷下沿柱状晶粒显示出晶间断裂。制成的样品的屈服强度（YS）为223±4 MPa，极限抗拉强度（UTS）为366±7 MPa，伸长率为5.3±0.3％。经过T6热处理后，由于形成了纳米尺寸的Al ₂ Cu（Mg）沉淀，YS和UTS急剧增加至368±6 MPa和455±10 MPa ，而延展性仍然相当相似。