High-resolution wear analysis of a ball-on-disc contact using low-activity radioactive isotopes

In this study, an advanced wear volume measuring technique making use of the radioisotope concentration method is applied to a ball-on-disc experiment, which allows highly precise online wear volume measurements and distinguishes among different wear regimes. Furthermore, the adhesive transfer of material from the activated specimen to the counteracting body was investigated with this method; it appears to be a promising technique for evaluating oil-protective capability. The experiments were carried out in a model tribometer following the ASTM D 6425 standard. A polyalphaolefin with zincdithiophosphate was used as lubricant. Two series of reciprocating sliding tests were conducted with different frequencies, 50 and 100 Hz. Results show a frequency-dependent running-in behaviour though the applied load was identical and constant. Using this precise online technique, a more accurate lifetime prediction can be estimated for applications like rolling bearings to which ASTM D 6425 refers.