Triboemission behavior of photons at dielectric/dielectric sliding:: Time dependence nature at 10-4-10-4 s

Photon triboemission behavior was studied experimentally during sliding of a diamond pin on a soda-lime glass in Ar gas atmosphere under reduced gas pressures of 40-90 Pa in time scales of 10(-4)-10(4) s. The patterns of the photon emission behavior were classified into two main types. On the time scale of 10(-3)-10(0) s, the pattern consisted of pretty equally spaced peaks. The mean period between the peaks was about 30 ms. The peaks occurred in groups, which lasted several hundreds of a millisecond. The groups of peaks also had a periodicity, which coincided with one of the disk rotation. In a time scale of 10(1)-10(4) s, the mean photon emission intensity decreased with an asymptotic low value. This behavior corresponds to the transition from wear-in to subsequent steady wear periods. The behavior of photon emission was interpreted in terms of the tribomicroplasma concept due to electric discharge of the surrounding gas. The interplay between the charge accumulation and the charge dissipation is responsible for the formation of various triboemission patterns. (C) 2003 American Institute of Physics.