Abstract:
The tribological behavior of Si3N4 ceramics and Si3N4/carbon fiber composites sliding against stainless steel under water lubrication was investigated using a thrust-bearing-type test method with normal applied loads varying from 0 to 1000 N in 100 N increments. In the case of the monolithic Si3N4, the friction coefficient was found to increase up to 0.4 the first time the applied load was increased from 100 to 200 N, and sudden failure of the ceramic ring specimen occurred. In the case of the Si3N4/carbon fiber composite, a low friction coefficient was maintained up to the maximum normal load of 1000 N. The addition of the carbon fibers to the silicon nitride ceramics effectively restricts material transfer from the stainless steel to the Si3N4 worn surface due to reduction of solid-solid contact through the solid lubricating effect of the carbon fibers.
