Wear and friction behaviour of alumina/mullite composite by sol–gel infiltration technique

Structural ceramics are those ceramic materials that possess sufficient mechanical properties for use as load bearing components. Ceramics based on alumina have been used in commercial applications for many years because of their availability and low cost. In this investigation we studied and explored the influence of mullite phase, speed and load values on friction and wear behaviour of alumina ceramic. Wear tests for alumina and composites contained mullite from 0 to 11 vol% were carried out with a ball-on-disc machine. Tribological tests were under 2.5, 5, 7.5 and 10 N load, at the speeds of 0.15, 0.3 and 0.6 m/s and unlubricated conditions in air. Wear rates were deduced from mass loss. The wear rate for alumina was in order of 6.76 × 10−5–1.66 × 10−4 mm3/N m, while the wear rate of alumina/mullite composites was in the order of 4.6 × 10−5–1.3 × 10−4 mm3/N m. The results indicate that wear rates and friction coefficient of alumina/mullite composites are lower than alumina ceramics.