Diamond Like Carbon Coatings - Tribological Possibilities And Limitations In Applications On Sintered Silicon Carbide Bearing And Seal Faces

Lecturepg. 93Promising new developments to master friction and wear under fry run conditions are diamond like carbon coatings. They offer high hardness and wear resistance, combined with a low coefficient of friction. Best coating results are achieved when deposited on sintered silicon carbide surfaces. DLC coatings on SSiC seal and bearing faces have been evaluated. Tests show that with DLC coatings coefficients of friction as low as 0.05 can be achieved in dry run. Loading conditions and design criteria determine the application limits of the coatings, which are outlined. The typical failure mechanisms of coatings are discussed. Application examples are given for gas seals and pump bearings, where the dry run situations, frictional failure might be a concern. It is also shown that DLC coatings give only excellent results when used on a well-designed component under low loads