The Influence of Cu/Fe Ratio on the Tribological Behavior of Brake Friction Materials
The Influence of Cu/Fe Ratio on the Tribological Behavior of Brake Friction Materials
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Cu/Fe比对制动摩擦材料摩擦学行为的影响
DOI：
10.1007/s11249-017-0961-2
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发表时间：
2018-03-01
影响因子：
3.2
通讯作者：
Zhang, Xiaolu
中科院分区：
文献类型：
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作者：
Peng, Tao;Yan, Qingzhi;Zhang, Xiaolu
铜和铁是摩擦材料的主要成分，其中铁过去常用作摩擦增强剂。但是在我们最近的研究中，摩擦系数（COF）随着复合材料中铁含量的增加而降低。为了研究Cu/Fe比对复合材料在模拟制动条件下摩擦学性能的影响，采用盘-盘结构的缩尺试验装置，在不同初始制动速度（IBS）下进行了摩擦学性能试验。研究了不同复合材料摩擦表面的平均摩擦系数、磨损率、表面形貌和化学组成的变化。结果表明，含铁量较高的复合材料总是表现出较低的平均摩擦系数和磨损率，这与以往的研究不同。这是因为，在恶劣的制动条件下，复合材料的摩擦学行为主要取决于表面的摩擦氧化膜的演变，而不仅仅是在基体本身。Fe含量的增加促进了摩擦氧化膜的形成，同时又抑制了摩擦氧化膜的破坏，从而降低了摩擦副的平均摩擦系数和磨损率，提高了摩擦副的平均摩擦系数和磨损率转变的临界摩擦磨损强度。本工作还提供了一种通过剥离试验表征摩擦膜断裂强度的方法。
Copper and iron are the major ingredients in friction materials, among which Fe often been served as friction reinforcement in the past. But in our recent study, the coefficients of friction (COF) decreased with increasing iron content in composites. In order to study the influence of Cu/Fe ratio on the tribological behavior of the composite under simulative braking conditions, a subscale testing apparatus with the pad-on-disk configuration under various initial braking speeds (IBS) was applied. The changes in mean COFs, wear rates, morphologies and chemical constitutions of friction surface for different composites were investigated. Results showed that the composite containing more Fe content always showed lower mean COF and wear rate, which different from the previous studies. This is because, under severe braking conditions, the tribological behavior of composite mainly depends on the evolution of tribo-oxide film on the surface, not just on the substrate themselves. Higher Fe content accelerated the formation of tribo-oxide film and in turn inhibited the destruction of tribo-oxide film on the surface, which leading to lower mean COF and wear rate, as well as a higher critical IBS for the transition of mean COF and wear rate. This work also provides a way to characterize the fracture strength of tribo-film by carried out a peeling test.