Triboemission, tribochemical reaction, and friction and wear in ceramics under various n-butane gas pressures

The triboemission behaviour of negatively and positively charged particles and photons generated by scratching a Si3N4 disc with a conical diamond stylus was studied under various gas pressures of n-butane as a model compound of typical paraffinic lubricating oil. The triboemission behaviour of photon emission in a frictional system of an Al2O3 ball sliding on Al2O3 and Si3N4 discs was also measured under various n-butane gas pressures. Further, the friction and wear in the frictional system of an Al2O3 ball sliding on an Si3N4 disc were studied under various n-butane gas pressures. The triboemission intensities of three kinds of energetic particles, negatively and positively charged particles and photons, become a maximum at a particular n-butane gas pressure. When the n-butane gas pressure is such that triboemission is a maximum, the formation of friction polymer-like high molecular weight products is at a maximum, and friction and wear of the ball decreases to a minimum. It has been concluded that the friction polymer-like high molecular weight products are formed through tribochemical reactions triggered by triboemission phenomena and help reduce the friction and wear of the solids. Copyright (C) 1996 Elsevier Science Ltd