| This research has established feasibility of surface temperature characterization using ruby fluorescence. Study was performed in pin-on-disk geometry, with balls made of different plastics sliding against the sapphire disk. Fluorescence signal was collected from a 400 m m diameter and 0.3 m m thick circular ruby film epitaxially regrown on top of the sapphire. The information from shifts in the ruby R-lines peaks was used for temperature characterization. Although the method has a potential of simultaneous characterization of temperature and pressure at the sliding interface, presently pressure is treated as an error.;Nominal temperature rise was studied as a function of velocity and load for nylon, Teflon and Delrin. Experiments were performed for the velocity range of 10 to 70 cm/s and for the load range of 4 to 11 Newton. The nominal temperature change was found to vary linearly with velocity and load. There are preliminary indications that the coefficient of proportionality is a product of the material-dependent friction coefficient and a factor, constant for a particular problem geometry.;Local temperature profiles for Teflon and Delrin were studied using gated signal integration. Feasibility has been demonstrated of measuring temperature profiles as a function of the distance along the sliding track, with temporal resolution of 1 ms. The experiments, however, were complicated by the unknown pressure contribution to the lineshifts and by the local temperature changes due to such factors as changes in the contact area due to wear, surface modification of the plastics, formation of the transfer film on the surface of sapphire. |
