Processing and Wear Behavior of Cr-Al2O3-ZrO2 and Mo-Al2O3-ZrO2 Composites

The processing and sliding wear behavior of reactively sintered metal-ceramic composites were investigated. The materials were made by pressureless sintering of powder metallurgically prepared mixtures containing alumina and a metal, such as Cr or Mo together with a small quantity of aluminum. The wear resistance of the composites was investigated under unlubricated conditions in ball-on-disk tests against steel and 3Y-TZP balls. Pure alumina and 3Y-TZP disks were tested as reference materials in order to obtain a ranking. The composites showed lower wear rates than 3Y-TZP against both ball materials. Compared to the wear of alumina disks, the composites showed higher wear rates against steel balls, and similar rates against 3Y-TZP balls. Investigation s of the ball wear showed higher wear rates of 3Y-TZP balls as opposed to steel balls for all investigated disk materials, indicating that the materials are more suitable for hybrid material couplings "composite against steel" than for purely ceramic systems.