Kim Kyungmok, Ko Joon Soo
Department of Aerospace Engineering, School of Aerospace and Mechanical Engineering, Korea Aerospace University, 76 Hanggongdaehang-ro, Deogyang-gu, Goyang-si, Gyeonggi-do 412-791, Korea.
Materials (Basel). 2016 Sep 3;9(9):754. doi: 10.3390/ma9090754.
This article investigates the effect of contact ageing on fretting damage of an epoxy-based cathodic electro-deposited coating for use on automotive seat slide tracks (made of cold-rolled high strength steel). Static normal load was induced at the contact between the coating and an AISI52100 ball for a certain duration. It was identified that plastically deformed contact area increased logarithmically as a function of time when the contact was under static normal load. Fretting tests after various durations of static contact were conducted using a ball-on-flat plate apparatus. All fretting tests were halted when the friction coefficient reached a critical value of 0.5, indicating complete coating failure. The total number of fretting cycles to the critical friction coefficient was found to vary with the duration of static contact before fretting. It was identified that the number of cycles to the critical friction coefficient decreased with the increased duration of static contact. Meanwhile, the friction coefficient at steady-state sliding was not greatly affected by the duration of static contact before fretting. Finally, the relation between coating thickness after indentation creep and the number of cycles to the critical friction coefficient was found to be linear. Obtained results show that the duration of static contact before fretting has an influence on the fretting lifetime of an electro-deposited coating.
本文研究了接触时效对用于汽车座椅滑轨（由冷轧高强度钢制成）的环氧基阴极电沉积涂层微动损伤的影响。在涂层与AISI52100球之间的接触处施加一定时间的静态法向载荷。结果表明，当接触处于静态法向载荷下时，塑性变形接触面积随时间呈对数增加。使用平板-球摩擦磨损试验机对不同静态接触时间后的微动试验进行了测试。当摩擦系数达到临界值0.5时，所有微动试验均停止，这表明涂层完全失效。发现达到临界摩擦系数的微动循环总数随微动前静态接触时间的变化而变化。结果表明，达到临界摩擦系数的循环次数随静态接触时间的增加而减少。同时，稳态滑动时的摩擦系数受微动前静态接触时间的影响不大。最后，发现压痕蠕变后涂层厚度与达到临界摩擦系数的循环次数之间呈线性关系。所得结果表明，微动前的静态接触时间对电沉积涂层的微动寿命有影响。
