TRIBOEMISSION OF CHARGED-PARTICLES FROM VARIOUS SOLIDS UNDER BOUNDARY LUBRICATION CONDITIONS

Triboemission under boundary lubrication conditions from various solids has successfully been measured. The dependence of triboemission intensity on time, normal force and sliding velocity was studied for negatively and positively charged particles emitted while scratching various metals, ceramics and polymers with a diamond stylus under boundary lubrication with saturated hydrocarbon liquids. Negatively charged particles were detected more intensely than positively charged particles for all solids tested except PTFE. The emission intensity increased with normal force and sliding velocity, and was high for insulating solids such as ceramics and polymers, while low for metals. The emission intensities under boundary lubrication were lower than under dry friction in room air, although the friction coefficients were comparable. The results are discussed in relation to the emission characteristics under dry sliding in room air.