Increase in wear resistance of nickel plasma coatings under traditional and combined treatment conditions

Abstract

The paper reports the prospective approaches to the increase in wear resistance of nickel plasma coatings. We considered the features of the two methods: combined high-energy heating by high frequency currents and spraying of composite cermet coatings of powder mixtures. The research provides the results of comparative wear resistance tests of the investigated nickel coatings under the conditions of sliding friction. The obtained fused and cermet coatings have a higher wear resistance compared to the original ones. The samples with composite coatings showed a significant decrease in the volumetric wear, averaging 56% along the entire length of the friction path due to the introduction of ceramic particles with high hardness (12150…15840 MPa) into the powder mixture. We present the results of the chemical composition research of nickel-ceramic powder mixture components and the sprayed cermet coating. The composite coating is established to have an increase in oxygen content owing to the intensive oxidation in the process of plasma spraying. There is a decrease in the percentage of the basic elements of the powder mixture, namely of aluminum and nickel. There is also an insignificant change in the share of the remaining chemical elements.