Ceramic Wear in Indentation and Sliding Contact

Abstract

This paper discusses the various wear mechanisms involved with single-crystal ceramic materials in indentation and in sliding contacts. Experiments simulating interfacial events have been conducted with hemispherical, conical, and pyramidal indenters (riders).

With spherical riders, under either abrasive or adhesive conditions, two types of fracture pits have been observed. First, spherical-shaped fracture pits and wear particles are found as a result of either indenting or sliding. These are shown to be due to a spherical-shaped fracture along the circular or spherical stress trajectories. Second, polyhedral fracture pits and debris, produced by anisotropic fracture, are also found both during indenting and sliding. These are primarily controlled by surface and subsurface cracking along cleavage planes.

Several quantitative results have also been obtained from this work. For example, using a pyramidal diamond, crack length of Mn-Zn ferrite in the indentation process grows linearly with increasing normal load. Moreover, the critical load to fracture both in indentation and sliding is found to be directly proportional to the indenter radius.

Finally, the tangential forces present during sliding are very potent in producing conditions for fracture at the surface. Under such conditions, the observed anisotropy of friction and plastic deformation is explained on the basis of the primary slip systems of these ceramics.

Presented at the 39th Annual Meeting in Chicago, Illinois, May 7–10, 1985

Notes

Presented at the 39th Annual Meeting in Chicago, Illinois, May 7–10, 1985