Conventional thermal processing may not always be well-suited for modifying the unique, as-built microstructure of Additively Manufactured (AM) AlSi10Mg. Conventional post-build processing of AM AlSi10Mg components involves a Solution Heat Treatment (SHT) at elevated temperatures (∼500 °C) followed by low-temperature aging (170 °C). Here we characterize low-temperature aging (170 °C) of AM AlSi10Mg components both with and without a conventional solution heat treatment. The samples without a solution heat treatment are first held at room temperature for several months, during which we monitored the reduction of Si in the Al matrix, from 4.74 to 3.98 at% with limited changes in hardness. We also correlate the as-built microstructure back to the processing conditions. During the room temperature hold, and when these samples are subsequently aged at 170 °C without a solution heat treatment, they retain a eutectic ribbon microstructure but lose the supersaturation of Si within the Al matrix with aging. These samples reach a peak hardness after 2 h at 170 °C that is approximately 50 % higher than the peak hardness of SHT samples after 5 h at 170 °C. We contrast the microstructure and density changes resulting from both heat treatment paths and explain how this modified heat treatment complements AM AlSi10Mg’s unique, as-built microstructure.

常规热处理可能并不总是非常适合修改增材制造（AM）AlSi10Mg独特的，已建成的微观结构。AM AlSi10Mg组件的常规后加工过程包括在高温（〜500°C）下进行固溶热处理（SHT），然后进行低温时效（170°C）。在此，我们对采用和不采用常规固溶热处理的AM AlSi10Mg组件进行低温老化（170°C）进行了表征。首先将未经固溶处理的样品在室温下放置几个月，在此期间，我们监测了Al基体中Si的含量从4.74 at％减少到3.98 at％，且硬度变化有限。我们还将已建成的微结构与加工条件关联起来。在室温下，当这些样品随后在不进行固溶热处理的情况下于170°C时效时，它们保留了共晶带状组织，但随着时效而失去了Al基体中Si的过饱和度。这些样品在170°C下2小时后达到峰值硬度，比SHT样品在170°C下5小时后的峰值硬度高约50％。我们对比了两种热处理路径导致的微观结构和密度变化，并解释了这种改进的热处理如何补充AM AlSi10Mg独特的竣工微观结构。