Abstract The transition in wear regime is a tribological phenomenon observed in many materials, where a sudden change in wear regime (from moderate to severe) occurs when operating parameters (e.g. pressure or sliding velocity) are changed. However, this phenomenon is rarely explored in brake friction materials (BFMs). Severe wear regime for BFMs results in an increase in cost and leads to environmental issues due to the high amount of loss in material. This work aims to study the transition in BFM applying different levels of pressure, where a BFM was rubbed against a gray cast iron disc in a tribometer. The tribofilm deposited on the disc surface and the area ratio of contact plateaus of BFMs were analyzed. The coefficient of friction (COF) and the BFM's wear were also measured. The wear regime changed from moderate to severe at a limit pressure of 90 bar. At the severe wear regime, a sudden increase in the COF was observed, and the wear of the BFM was approximately 13 times higher than in the moderate wear regime. It was also seen a removal of the tribofilm deposited on the disc's surface and a reduction of contact plateaus over the BFM's surface.

中文翻译：

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压力对制动摩擦材料中重度磨损状态之间过渡的影响

摘要 磨损状态的转变是在许多材料中观察到的一种摩擦学现象，当操作参数（例如压力或滑动速度）发生变化时，磨损状态会发生突然的变化（从中等到严重）。然而，在制动摩擦材料 (BFM) 中很少探索这种现象。BFM 的严重磨损会导致成本增加，并由于材料损失量大而导致环境问题。这项工作旨在研究应用不同压力水平的 BFM 的转变，其中 BFM 与摩擦计中的灰铸铁盘摩擦。分析了沉积在圆盘表面的摩擦膜和 BFM 接触平台的面积比。还测量了摩擦系数 (COF) 和 BFM 的磨损。在 90 巴的极限压力下，磨损状况从中等变为严重。在严重磨损状态下，观察到 COF 突然增加，BFM 的磨损大约是中等磨损状态下的 13 倍。还可以看到沉积在盘表面的摩擦膜被去除，BFM 表面的接触平台减少。