Abstract Cold spray deposition (CSD) emerged as an additive manufacturing process in recent years. It features the highest efficiency among all metal additive manufacturing processes. In this work, the deposition mechanism of brittle reinforcing particles during the CSD of metal matrix composites (MMCs) was investigated. The rebound and fragmentation of brittle microparticles during deposition were investigated at nanosecond level and with microscale resolution through in-situ observation. For the first time, the velocity that determines the transition from particle rebound to particle fragmentation was identified. Herein, this velocity is defined as “fragmentation velocity”. The X-ray computed tomography on CSD deposits reveal that most of the diamonds in the deposits were fragments of the original particles and their volume fraction significantly depended on their impact velocities relative to the fragmentation velocity. Based on these findings along with microstructure characterizations, the deposition mechanism of brittle reinforcing particles during the CSD of MMCs is proposed.

中文翻译：

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揭示通过冷喷涂增材制造制造的金属基复合材料中脆性颗粒的沉积机制

摘要 冷喷涂沉积 (CSD) 是近年来作为一种增材制造工艺出现的。它具有所有金属增材制造工艺中最高的效率。在这项工作中，研究了脆性增强颗粒在金属基复合材料 (MMC) 的 CSD 过程中的沉积机制。通过原位观察，在纳秒级和微米级分辨率下研究了沉积过程中脆性微粒的回弹和碎裂。首次确定了决定从粒子反弹到粒子碎裂转变的速度。在此，将该速度定义为“碎裂速度”。CSD 矿床的 X 射线计算机断层扫描显示，矿床中的大部分钻石是原始颗粒的碎片，它们的体积分数显着取决于它们相对于碎裂速度的撞击速度。基于这些发现以及微观结构特征，提出了脆性增强颗粒在 MMC 的 CSD 过程中的沉积机制。