Self-replenishing solid lubricant films on boron carbide


Erdemir A., Eryilmaz O., Fenske G.

SURFACE ENGINEERING, vol.15, no.4, pp.291-295, 1999 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 15 Issue: 4
  • Publication Date: 1999
  • Doi Number: 10.1179/026708499101516605
  • Title of Journal : SURFACE ENGINEERING
  • Page Numbers: pp.291-295

Abstract

This study introduces a simple annealing procedure that leads to the formation of a self-replenishing solid lubricant film on bulk boron carbide (B4C) and its coatings. The procedure uses short duration annealing at 800 degrees C far 15 min. Subsequently, the specimens are cooled to room temperature and tested in a pin on disc machine. During annealing, B4C reacts with oxygen in air and forms a glasslike boron oxide (B2O3) layer an the exposed surface. Eventually, this layer reacts spontaneously with moisture in the surrounding air, thus farming a thin baric acid (H3BO3) film. The friction coefficients of 440C steel and zirconia pins against this film are 0.04-0.06. Electron microscopy and Raman spectroscopy were used to elucidate the formation and self-lubricating mechanisms of this solid boundary film on sliding B4C surfaces. (C) 1999 IoM Communications Ltd.