Papers by Keyword: Ball-On-Disk

Abstract: In this study, the tempering effect on the wear characteristics of induction-hardened SPS5 steel was investigated. For this purpose, three tempering conditions were applied to control the hardness and microstructure of heat-treated SPS5 steel. Ball-on-disk wear tests have been performed using zircornia balls on the tempered specimens to determine the variation of wear characteristics. The results showed that friction coefficient decreased with increasing hardness for induction-hardened SPS5 steel. This seems to occur because real contact area between specimen and mating ball was affected by the specimen hardness. Also, we observe the wear type changes from the plowing wear to the adhesive wear as the hardness increases and the adhesive wear particles act as an obstacle to the transmission of the force of friction, reducing the coefficient of friction and the wear rate.

Abstract: The tribological performance of ordered mesoporous carbons (CMK-3) as lubricant additives is investigated at ambient temperature. The effects of CMK-3 on the frictional forces, wear amounts and cycles to scuffing are measured using a ball-on-disk tester. It was found that there was little difference in the frictional forces and wear amounts of the oils with and without CMK-3. However, the scuffing time of the oil with CMK-3 was much longer than that of the pure mineral oil in sliding tests. CMK-3 were very effective on maintaining the oil gap and protecting the surfaces in boundary lubricated sliding.

Abstract: DLC (Diamond Like Carbon) films show very desirable surface interactions with high hardness, low friction coefficient, and good wear-resistance properties. The friction behavior of hydrogenated DLC film is dependent on tribological environment, especially surrounding temperature. In this work, the tribological behaviors of DLC (Diamond-like carbon) films, prepared by the radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) method, were studied in elevated temperatures. The ball-on-disk tests with DLC films on steel specimens were conducted at a sliding speed of 60 rpm, a load of 10 N, and surrounding various temperatures of 25
, 40
, 55
and 75
. The results show considerable dependency of DLC tribological parameters on temperature. The friction coefficient decreased as the surrounding temperature increased. After tests the wear tracks of hydrogenated DLC film were analyzed by optical microscope, scanning electron spectroscopy (SEM) and Raman spectroscopy. The surface roughness and 3-D images of wear track were also obtained by an atomic force microscope (AFM).

Abstract: The tribological performance of multi-walled carbon nanotubes (MWNT) in mineral oils is investigated at ambient temperature. The frictional forces, wear amounts and cycles to scuffing of the oils with nanotubes and without those were measured using the ball-on-disk tester. It was found that there were little differences in the frictional forces and wear amounts of two oils. However, the scuffing times of oils with nanotubes were much longer than those of oils without nanotubes in sliding tests. The nanotubes were very effective on maintaining the oil gap and protecting the surfaces in boundary lubricated sliding.