Cold spray (CS) is a solid-state additive manufacturing process that can create high-density, high-performance deposits for many applications. Aluminum alloys have been the target of recent CS research due to their excellent mechanical behavior when cold-sprayed. The introduction of new Al alloys to CS is of interest as unique properties may be achieved, especially when powder is heat-treated prior to deposition. In this study, three batches of Al F357 powder—a control as-atomized, heat-treated at 230 °C for 75 min and heat-treated at 385 °C for 6 h—were studied. Scanning electron microscopy revealed microstructural modifications after heat treatment in the powder and sprayed deposits. X-ray diffraction highlighted the presence of eutectic Si, Mg2Si and SiO2 in all specimens. Energy-dispersive spectroscopy showed the spheroidization of Si during the 385 °C heat treatment, with an increase in the fraction of Mg2Si during both treatments. Nanohardness and microhardness testing showed a decrease in hardness with thermal processing in both the powder and sprayed deposits. Tensile testing demonstrated ductile behavior from both heat-treated powders, but significantly higher strengths from the 230 °C treatment. These results suggest Al F357 may be used in CS when appropriate powder heat treatments are applied.

中文翻译：

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用于冷喷涂应用的 F357 铝粉的显微组织和机械性能评估

冷喷涂 (CS) 是一种固态增材制造工艺，可以为许多应用创建高密度、高性能的沉积物。铝合金由于其在冷喷涂时的优异机械性能而成为最近 CS 研究的目标。将新的铝合金引入 CS 是令人感兴趣的，因为可以实现独特的性能，特别是当粉末在沉积前进行热处理时。在这项研究中，研究了三批 Al F357 粉末——雾化后的对照，在 230 °C 下热处理 75 分钟，在 385 °C 下热处理 6 小时。扫描电子显微镜显示粉末和喷涂沉积物热处理后的微观结构发生变化。X 射线衍射突出显示所有样品中存在共晶 Si、Mg2Si 和 SiO2。能量色散光谱显示，在 385 °C 热处理过程中，Si 发生球化，两种处理过程中 Mg2Si 的比例都有所增加。纳米硬度和显微硬度测试表明粉末和喷涂沉积物的硬度随着热处理而降低。拉伸测试表明，两种热处理粉末都具有延展性，但 230 °C 处理的强度明显更高。这些结果表明，当应用适当的粉末热处理时，Al F357 可用于 CS。但 230 °C 处理的强度明显更高。这些结果表明，当应用适当的粉末热处理时，Al F357 可用于 CS。但 230 °C 处理的强度明显更高。这些结果表明，当应用适当的粉末热处理时，Al F357 可用于 CS。