THE INFLUENCE OF GRAPHITE MODIFICATION OF OXIDECOATINGS PRODUCED ON MG-AZ31B ALLOY BY PLASMAELECTROLYTIC OXIDATION ON THEIR TRIBOLOGICALPROPERTIES

The manuscript discusses the impact of graphite modification of oxide coatings formed on the AZ31Bmagnesium alloy through plasma electrolytic oxidation on tribological properties. Constant oxidationparameters were applied: current density of 18 A/dm, oxidation time of 30 minutes, pulse frequency of 100Hz, and voltage limitation in positive current cycles of 400 V. Graphite modification was carried out usingan ultrasonic method, with process parameters (modifier content and treatment time) selected based on atwo-dimensional experimental design. Tribological tests were performed on a T-17 tester under dry frictionconditions using a PEEK-HPV pin. Graphite modification resulted in a reduction in the friction coefficientand mass wear of the pin, as well as an increase in the mass change of the sample. Additionally, roughness andcoating thickness measurements were carried out.