Search Results

A systematic study has been carried out to investigate the effect of change in the stiffness of the system incorporating a tribo contact, on the operational characteristics of a friction pair. Using a pin on disk apparatus six different system stiffnesses were introduced. With each system stiffness a steel sample is slide against two counter bodies: a smooth metal surface, and an abrasive surface. Friction force, normal force, and wear rate are measured. Results indicate that system stiffness has significant effect on wear, vibration, and contact forces. An increase in system stiffness is found to increase wear rate. As the wear rate increased, the coefficient of friction was also found to increase. Mathematical models have been developed to predict wear under varying system stiffness. These results are of particular importance in miniature devices involving moving parts.

Wear characteristics of four bearing materials have been investigated under different sliding conditions. The bearing materials used were CDA 954, CDA 863, CDA 932, and CDA 938. Using a Taber Wear Tester, a cylinder on a flat geometry was used as a tribo contact pair. All bearing materials in the form of a thick cylindrical disk were subjected to combined sliding-rolling motion against a rotating flat disk. The flat disk was either an abrasive disk, or a very soft steel disk, or a hardened steel disk with and without lubrication. Wear was measured as weight loss after several thousand cycles of rotation. Maximum wear of the bearing materials occurred when the counter body was a very soft steel disk. These results together with the wear rate of each bearing material sliding against four different counter bodies are presented. These results are found to be of practical importance in the design and application of journal bearings made of materials used in this investigation.