Three-dimensional (3D) printed Sc-modified Al alloy by powder bed fusion (PBF) provides significant strength and ductility without hot tearing during the process. This kind of 3D-printable high specific strength materials exhibits great potential in lightweight applications. Due to the lesser design limitation through the 3D printing process, the degree of lightweight is greatly affected by the specific strength of the materials. Hence, to further improve the mechanical properties of the material through process optimisation or post-treatment is of great importance. Microstructure feature variations due to different processing parameters are well known for traditional processes and materials. This study explores the parameter–microstructure–performance relationship of 3D printed Sc-modified Al alloys from the perspective of melt pool interactions. According to the stress concentration effect and Hall–Petch effect, the mechanical properties of the 3D printed materials vary greatly depending on the difference in defect size, shape and grain size.

通过粉末床熔合（PBF）进行的三维（3D）印刷Sc改性铝合金可提供显着的强度和延展性，而在加工过程中不会发生热撕裂。这种可3D打印的高比强度材料在轻型应用中显示出巨大潜力。由于3D打印过程对设计的限制较小，因此轻量化的程度受材料的比强度影响很大。因此，通过工艺优化或后处理进一步改善材料的机械性能非常重要。对于传统工艺和材料，由于不同的加工参数而导致的微结构特征变化是众所周知的。这项研究从熔池相互作用的角度探讨了3D打印的Sc改性铝合金的参数-微观结构-性能关系。