In order to provide a basis for future optimization and control of the cold spray process, we experimentally studied the impact of various factors on the ductility (% elongation) of copper coatings. For the current application, cold-sprayed copper is employed as a corrosion barrier on carbon steel, while in addition to this, sufficient ductility is required for mechanical integrity. Results show that the cold-sprayed copper coating ductility increases with annealing temperature. A corresponding linear relationship is also derived with ductility and hardness. The current investigation further shows that there can be significant variability in ductility when the feedstock powder characteristics (e.g., chemical composition) are changed while keeping the spray and heat treatment conditions constant. Configuration/substrate dimensions are also considered as factors affecting the ductility of the copper during the cold spray process. The main findings that were observed include: (1) an increase in ductility from ~ 9 to ~ 29% when heat treating the samples from 320 to 600 °C; (2) a variation in ductility from ~ 8 to ~ 39% upon changing powder characteristics; and (3) a decrease in ductility from ~ 27 to ~ 15%, upon increasing the size of the substrate and by changing its geometry.

中文翻译：

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影响冷喷涂铜涂层延展性的因素

为了为今后冷喷涂工艺的优化和控制提供依据，我们通过实验研究了各种因素对铜涂层延展性（%伸长率）的影响。对于目前的应用，冷喷涂铜被用作碳钢上的腐蚀屏障，除此之外，机械完整性还需要足够的延展性。结果表明，冷喷涂铜镀层的延展性随退火温度的升高而增加。相应的线性关系也与延展性和硬度有关。当前的调查进一步表明，当原料粉末特性（例如，化学成分）发生变化，同时保持喷雾和热处理条件不变时，延展性可能会发生显着变化。在冷喷涂过程中，配置/基板尺寸也被视为影响铜延展性的因素。观察到的主要发现包括：(1) 将样品从 320°C 热处理到 600°C 时，延展性从 ~ 9% 增加到 ~29%；(2) 改变粉末特性后，延展性从 ~ 8% 变化到 ~ 39%；(3) 延展性从 ~ 27% 降低到 ~ 15%，随着基材尺寸的增加和其几何形状的改变。