Nanoscale in situ study of ZDDP tribofilm growth at aluminum-based interfaces using atomic force microscopy
Nanoscale in situ study of ZDDP tribofilm growth at aluminum-based interfaces using atomic force microscopy
复制标题
原子力显微镜原位纳米尺度研究ZDDP在铝基界面上的摩擦膜生长
DOI：
10.1016/j.triboint.2019.106075
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发表时间：
2020-03-01
影响因子：
6.2
通讯作者：
Carpick, R. W.
中科院分区：
文献类型：
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作者：
Gosvami, N. N.;Lahouij, I.;Carpick, R. W.
以二烷基二硫代磷酸锌(ZDDP)为基础的抗磨添加剂在汽车润滑油中是至关重要的，其在降低黑色金属合金磨损方面的有效性是公认的。然而，先前对轻质铝基合金的研究表明，ZDDP在铝基表面不是一种有效的抗磨剂，原因仍然存在争议。在这里，我们使用原位原子力显微镜(AFM)来研究氧化铝微胶体探针与由铝(带有自然氧化物)或氧化铝(单晶蓝宝石)组成的衬底之间滑动界面上的纳米ZDDP衍生摩擦膜。实验表明，ZDDP摩擦膜在两种衬底上形成，支持摩擦膜的形成关键涉及热激活、应力辅助的化学反应，而不需要与源自衬底的磨屑进行阳离子交换。
Zinc dialkyldithiophosphate (ZDDP)-based antiwear additives are crucial in automotive lubricants, where its effectiveness in reducing wear of ferrous alloys is well established. However, prior studies of light-weight aluminum-based alloys reveal that ZDDP is not as effective an anti-wear agent on Al-based surfaces for reasons that remain under debate. Here we use in situ atomic force microscopy (AFM) to study nanoscale ZDDP-derived tribofilms at the sliding interface between an alumina microcolloid probe and substrates comprised of either aluminum (with native oxide) or aluminum oxide (single crystal sapphire). The experiments reveal that ZDDP tribofilms form on both substrates, supporting the idea that tribofilm formation crucially involves thermally-activated, stress-assisted chemical reactions, and does not require cation exchange from wear debris originating from the substrate.