Impact-bonding with aluminum, silver, and gold microparticles: Toward understanding the role of native oxide layer
Impact-bonding with aluminum, silver, and gold microparticles: Toward understanding the role of native oxide layer
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DOI：
10.1016/j.apsusc.2019.01.111
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发表时间：
2019-05-15
影响因子：
6.7
通讯作者：
Schuh, Christopher A.
中科院分区：
文献类型：
--
作者：
Hassani-Gangaraj, Mostafa;Veysset, David;Schuh, Christopher A.
冷喷涂过程中的粘合现象与自然表面氧化层的破裂有关，从而产生紧密的金属接触。在这里，我们通过对单个微粒的直接原位观察，解决了有或没有明显自然氧化物的金属结合的瞬间问题。我们发现，自然氧化层的断裂并不是冲击结合的唯一物理障碍；即使是贵金属也必须在冲击时表现出不稳定的喷射才能获得结合。然而，表面氧化物无疑是粘合的一个额外障碍，并可以大幅提高临界速度。
Bonding during cold spray has been phenomenologically associated with the breakup of the native surface oxide layer to produce intimate metallic contacts. Here, we resolve the instant of bonding for metals both with and without a significant native oxide, through direct in-situ observation of individual microparticles. We show that fracture of the native oxide layer is not the only physical barrier to impact adhesion; even noble gold must exhibit unstable jetting upon impact in order to attain bonding. However, surface oxide certainly presents an additional barrier to bonding and can increase the critical velocity by a large factor.