This work explores the impact of thermally preprocessing recycled austenitic stainless-steel powder for solid-state cold spray metal additive manufacturing with a focus on increasing deposition quality and coating density while maintaining mechanical integrity. The recycled stainless-steel scrap was gas-atomized using a novel mobile foundry manufactured by MolyWorks Materials Corporation. The powder was thermally treated based upon thermodynamic modeling using Thermo-Calc. The powder and sprayed specimens were characterized using particle size–shape analysis, microscopy, x-ray diffraction, and nanoindentation. Diffraction results highlighted the presence of both austenite and ferrite phases in the powder. Nanoindentation confirmed that thermally processing the feedstock powder at the austenitization temperature decreased the amount of ferrite present, which was consistent with the porosity observed in the deposits due to the lower yield strength of austenite relative to ferrite. The untreated powder deposits exhibited extensive porosity and microcracking, as opposed to the virtually fully dense deposit from the heat-treated powder.

中文翻译：

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用于冷喷涂应用的回收战场不锈钢废料的热处理

这项工作探讨了热预处理再生奥氏体不锈钢粉末对固态冷喷涂金属增材制造的影响，重点是提高沉积质量和涂层密度，同时保持机械完整性。使用 MolyWorks Materials Corporation 制造的新型移动铸造厂对回收的不锈钢废料进行气体雾化。基于使用 Thermo-Calc 的热力学模型对粉末进行热处理。使用粒度-形状分析、显微镜、X 射线衍射和纳米压痕对粉末和喷涂样品进行表征。衍射结果突出显示粉末中同时存在奥氏体和铁素体相。纳米压痕证实，在奥氏体化温度下对原料粉末进行热处理会减少铁素体的存在量，这与由于奥氏体相对于铁素体的屈服强度较低而在沉积物中观察到的孔隙率一致。与热处理粉末的几乎完全致密的沉积物相反，未处理的粉末沉积物表现出广泛的孔隙率和微裂纹。