Study On The Friction And Wear Properties Of Reaction-Bonded Silicon Carbide

Using the refitted pin-on-disk tribometre, which was used to test the friction and wear of material under different temperatures, the effects of particle sizes, particle distributions, alloying, experimental temperature and water lubricating on the friction and wear behaviors and mechanisms of reaction-bonded silicon carbide (RB-SiC) are systematically studied under the self-mated conditions. Furthermore, by the analyses of microstructures, X-ray diffraction and worn surfaces by SEM, the self-lubricating properties of RB-SiC were discussed also, in order to offer the references for applications as friction pairs and seal materials using reaction- bonded silicon carbide ceramics materials.From above, the results showed that the particle sizes and particle distributions would effect on the friction and wear properties of RB-SiC. Reaction-bonded silicon carbide composite ceramic with fine particles and its distribution of coarse particles and fine particles being 1:1 had good tribological properties and self-lubricating properties at elevated temperature. However, the friction coefficient and wear rate of RB-SiC with fine particle size would be decreased because it was favorable to form a smooth and stable oxidation film on friction surface. With the increase of fine particles content in RB-SiC, it also revealed good high temperature self-lubricating properties because of the increase of its oxidation degree at high temperature. Furthermore, the friction coefficient and wear rateof RB-SiC would be decreased sharply and revealed good tribological properties under water lubricating.The wear mechanism of RB-SiC was dominated by micro-cutting at room temperature. But it was changed from micro-cutting to oxidation fretting and spalling in friction process with the increase of temperature.In the end, one can find that the addition of titanium and molybdenum elements would be improved the dry tribological properties of RB-SiC under the elevated temperature, and the reaction-bonded silicon carbide with titanium behaves good self-lubricating properties at 600℃ especially. As an important result, the wear mechanism of alloying RB-SiC was mostly micro-cutting at room temperature, the spalling of oxidation film at 300℃, and the desquamating of SiC particles at 600℃.