INFLUENCE OF MICRO-ARC OXIDATION MODES ON MECHANICAL PROPERTIES OF ALUMINUM ALLOY SAMPLES

This paper presents the results of the experimental study influence of micro-arc oxidation (MAO) modes on the yield strength and temporary resistance of aluminum alloy samples marked 2024. The paper describes the research methodology, including the formation of hardened MAO layer on the surface of experimental samples and strength studies by means of experiments with tensile. The studies were conducted according to the theory of experiment planning for a fractional factorial experiment type 23-1. MDO process was carried out using an alkaline electrolyte that is why component concentration of electrolyte (potassium hydroxide - KOH and sodium silicate - Na2SiO3) and electrical parameters of the process, determined by capacity of technological plant, were selected as MAO process factors. Thickness and microhardness of MAO-layer on the cross-sections were determined as well as the yield strength and tensile strength. Regression equations were developed based on data that has been obtained and the conclusions about the degree of influence of modes of micro-arc oxidation on the mechanical properties of the samples were obtained. The results showed that the existence of MAO-layer had almost no effect on the tensile strength of the samples, but it promotes the yield strength increase, the value of which may be increased to 18% depending on the mode of processing. This work was conducted to study the prospects of using the technological method of surface modification - micro-arc oxidation method to improve not only durability but also the strength characteristics of aluminum alloy details.