Diesel lubricated ta-C coatings

Samples coated with tetrahedral amorphous carbon (ta-C) were investigated in two different oscillating test setups regarding their friction and wear properties. As lubricants petrodiesel, rapeseed methyl ester biodiesel and a mixture thereof were used. In the application-oriented test setup wear was considerably reduced and a low friction coefficient of 0.04 was achieved. Impurities of monoglycerides are assumed to be the cause for the friction-modifying effect.