Effect of hexagonal boron nitride (h-BN) addition on friction behavior of low-steel composite brake pad material for railway applications


YANAR H., PÜRÇEK G., Demirtas M. , Ayar H. H.

TRIBOLOGY INTERNATIONAL, vol.165, 2022 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 165
  • Publication Date: 2022
  • Doi Number: 10.1016/j.triboint.2021.107274
  • Title of Journal : TRIBOLOGY INTERNATIONAL
  • Keywords: Low-steel composite friction materials, High temperature solid lubricant, Hexagonal boron nitride (h-BN), Friction and wear, SOLID LUBRICANTS GRAPHITE, TRIBOLOGICAL PROPERTIES, WEAR

Abstract

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 degrees 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.