Successful cold spray processing requires the formation of metallurgical bonds at the interface between particle impact sites and the substrate. While surface contamination on either the particle or substrate can interfere with metallurgical bonding, the details of particle/substrate interface chemistry are usually obscured or lost during the nanoseconds-long particle impact process. To provide a direct, detailed account of particle-substrate interfacial chemistry, we perform post-mortem scanning transmission electron microscopy and spectroscopy of impact sites of single copper microparticles, launched with a laser-induced particle impact tester, on a copper substrate. In addition to native oxides, we find that amorphous carbon and spherical copper oxide dispersoids are also present near/at the interface. Further, these features are found to influence metallurgical bonding. These results offer additional considerations for optimizing the quality of the cold spray deposition process.

成功的冷喷涂加工需要在颗粒撞击部位和基材之间的界面形成冶金结合。虽然颗粒或基材上的表面污染会干扰冶金结合，但在纳秒长的颗粒撞击过程中，颗粒/基材界面化学的细节通常会被掩盖或丢失。为了提供对粒子-基材界面化学的直接、详细说明，我们对使用激光诱导粒子冲击测试仪在铜基材上发射的单个铜微粒的撞击部位进行了验尸扫描透射电子显微镜和光谱分析。除了天然氧化物外，我们发现无定形碳和球形氧化铜分散体也存在于界面附近/界面处。更远，发现这些特征会影响冶金结合。这些结果为优化冷喷涂沉积工艺的质量提供了额外的考虑。