A significant fraction of the non-exhaust particulate matter emissions from vehicular traffic comprises fine particles from the wear debris of brake pads and discs. Recent studies have shown that these emissions can be consistently reduced by using wear resistant disc coatings. This study thoroughly analyses the debris produced by a low-met brake pad, which is dyno-bench tested against both cast iron and WC-CoCr-coated brake discs. To achieve this, particles in the size range of 2.5 µm to 30 nm were collected and characterized. The results showed a consistent reduction in the particle emission as well as in the concentration of iron oxides, which are mainly released from the disc tribo-oxidation in the coated disc. Furthermore, a few tungsten carbides, released from the coating, were also observed in the wear fragments. The results of this study can be useful for improving the protective coating and consequently help in reducing particulate matter emission further.

中文翻译：

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制动衬片压在HVOF涂层圆盘上产生的空气传播的磨损碎片的特征

车辆排放的大量非排放颗粒物包括来自刹车片和制动盘磨损碎片的细颗粒。最近的研究表明，使用耐磨的圆盘涂层可以始终如一地减少这些排放。这项研究彻底分析了低厚度制动衬块产生的碎屑，该制动衬块已针对铸铁和WC-CoCr涂层的制动盘进行了dyno-bench测试。为此，收集并表征了2.5 µm至30 nm大小的颗粒。结果表明，颗粒排放以及铁氧化物的浓度持续降低，而铁氧化物的浓度主要是由涂层圆盘中的摩擦摩擦产生的。此外，在磨损碎片中还观察到了从涂层释放的少量碳化钨。