Abstract:
The friction coefficients of self-mated Ti
3SiC
2 with and without oxide powder lubricants from ambient temperature to 800 ℃ in air were investigated. The oxide powder lubricants including PbO,ZnO,NiO,TiO
2,B
2O
3,Fe
2O
3,MoO
3,MgO and Al
2O
3 in addition to conventional solid lubricants (graphite and MoS
2 as reference) were used. The results showed that the friction coefficient of self-mated Ti
3SiC
2 tribo-pair could be reduced greatly under lubrication of graphite and MoS
2 powders. Graphite powder was effective in friction reduction below 200 ℃. MoS
2 powder became ineffective above 500 ℃ because of oxidation. Some of the oxide powders were capable of reducing friction coefficient of self-mated Ti
3SiC
2 in narrow temperature range but exhibited higher friction coefficient than graphite and MoS
2 powders. From room temperature to 600 ℃,PbO was the most promising lubricant,while above 700 ℃,TiO
2 and NiO gave moderate friction coefficient. The CM(49lubricating mechanisms of graphite,MoS
2 and oxides powders were discussed in the following aspects,i.e.,film forming properties of the powder,the shear strength and chemical stability of the film.