Effect of hexagonal boron nitride (h-BN) addition on friction behavior of low-steel composite brake pad material for railway applications |
In this study, low-steel composite friction materials containing different amount of h-BN were developed for railway vehicles. Addition of h-BN has no considerable effect on mechanical properties of the matrix structure. However, h-BN addition significantly affects friction and wear properties of the matrix material. While h-BN increases coefficient of friction of samples at low disk surface temperatures, it has a reverse effect after the temperature reaches to a critical level of 250–300 °C. Also, addition of 1.5 wt% h-BN to the matrix brings about more stable changes in friction coefficient during the braking periods under the extreme conditions as compared to the h-BN-free sample. Furthermore, low h-BN addition into the matrix results in better lubricity properties at relatively high temperatures.
Keywords: Low-steel composite friction materials, Hexagonal boron nitride (h-BN), Friction and wear High temperature solid lubricant
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