Friction and outwearing of ceramic coatings formed by the microarc oxidation method

Abstract

The microarc oxidation (MAO) method by its power action on treated material can be referred to methods of surface strengthening by concentrated streams of energy. The local action of microarc discharges on a metal surface depends both on electric characteristics of microarc discharge and parameters of electrolyte and on characteristics of treated metal. Good wear resistance of MAO coatings is being explained by a high level of physical and mechanical characteristics and by their structural constitution. The aim of the investigations presented in this article is the estimation of MAO coating wear resistance compared with other wear-resistant materials. The basic trials of materials were conducted on abrasive outwearing using pin-on-disc friction schema. MAO layers with threadlike mono-crystals of α-Al₂O₃ (emery) have the best mechanical and tribotechnical characteristics. Such microstructures have MAO coatings on aluminium alloys of the Al-Cu-Mg system - duralumin. They represent the most effective structure ensuring high wear resistance.