Laser powder bed fusion produced Scalmalloy® is a high potential candidate in aerospace industry. However, fatigue properties are the Achilles heel of additive manufacturing process, impeding high-performance fatigue loaded applications. This paper aims to unveil the impact of unique bimodal microstructure on the quasi-static tensile and the fatigue properties. It is shown that the material intrinsic fatigue strength of Scalmalloy® outperforms its additively manufactured aluminium counterparts significantly, already reaching values of additively manufactured Ti-6Al-4V. Moreover, by evaluating the R-curve for Scalmalloy®, short crack growth was also taken into consideration for the analysis of the fatigue behaviour, elaborating an advanced Kitagawa-Takahashi diagram.

激光粉末床熔炼生产的 Scalmalloy® 是航空航天工业中极具潜力的候选材料。然而，疲劳性能是增材制造工艺的致命弱点，阻碍了高性能疲劳负载应用。本文旨在揭示独特的双峰微观结构对准静态拉伸和疲劳性能的影响。结果表明，Scalmalloy® 的材料固有疲劳强度明显优于其增材制造的铝材料，已经达到增材制造的 Ti-6Al-4V 的值。此外，通过评估 Scalmalloy® 的 R 曲线，在疲劳行为分析中也考虑了短裂纹扩展，制定了先进的 Kitagawa-Takahashi 图。