Automation of the micro-arc oxidation process

Abstract

Abstract. At present the significantly increased interest in micro-arc oxidation (MAO) encourages scientists to look for the solution of the problem of this technological process controllability. To solve this problem an automated technological installation MAO was developed, its structure and control principles are presented in this article. This device will allow to provide the controlled synthesis of MAO coatings and to identify MAO process patterns which contributes to commercialization of this technology. IntroductionMicro-arc oxidation (MAO) is a perspective technological process, demanded in many sectors of industry: automobile, aircraft and aerospace manufacturing, electronics, medicine, photonics and nanotechnology. Its essence lies in the surface treatment of parts made of valve metals and alloys, in particular aluminum, to impart them unique properties: high micro-hardness, wear resistance and corrosion resistance (increase the reliability and durability of machine parts); high thermal conductivity (allows us to produce smaller radiators with the same power dissipation); good biocompatibility (used in prosthetics); ordered pores structure of the top layer of the MAO coating (allows to grow arrays of nanowires in a matrix of aluminum oxide, for example, to obtain metamaterials).However, the complexity and multifactorial of MAO process prevents the commercial implementation of this technology, because the mode of equipment operation for each application has its own characteristics. To resolve this problem, it is necessary to install the relationship between MAO technological process parameters and properties of obtained coatings.Works of this kind have already been held in Russia [1] and abroad [2] -[5], but they could not provide enough information for a full and comprehensive analysis of the MAO process (the effect of only one or a group of parameters of MAO process on one or some more coating properties was studied and other factors were not considered). In addition, in these works the investigation of the MAO coatings properties was carried out only after receiving them. It was not possible to change the conditions for obtaining or control of coatings properties during the manufacturing process.

Analysis of the current density and electrolyte composition influence on the quality of micro-arc coatings

“…However, the considered oxidation method is characterized by heterogeneous factors that collectively affect the quality parameters of coatings [12], which indicates the need for their analytical description in order to establish optimal control technological effects. In addition, the imperfection of technological equipment and means of measuring the parameters of coatings in real time limit the widespread industrial introduction of microarc oxidation [13,14]. This article presents the results of an analysis of the current density and electrolyte composition effect, which made it possible to develop criteria for assessing the coatings quality by analyzing the electrical characteristics of the micro-arc oxidation method.…”

Parametric identification of the mathematical model of the micro-arc oxidation process

“…The combination of high micro-hardness and wear resistance with corrosion resistance ensures the wide use of products with such coatings in many industries [1][2][3]. A large number of studies has been devoted to improving the MAO process under consideration, among which one can note: imparting new properties to coatings by adding nanoparticles to the electrolyte [4][5][6], searching for new applications of MAO coatings [7,8], improving their characteristics [9][10][11][12], optimization [13][14][15][16][17][18] and control [19,20] of the oxidation process. A number of studies are devoted to the problems of identification of complex technical systems, in particular, in [21] a new algorithm for identification of a linear-time-invariant system using MATLAB is proposed.…”

Parametric identification of the mathematical model of the micro-arc oxidation process

“…A large number of studies have been devoted to the improvement of the considered MAO process, among which one can note the possibility of imparting new properties to coatings by adding nanoparticles to the electrolyte [ [4] , [5] , [6] ], the search for new applications of MAO coatings [ 7 , 8 ], the improvement of their characteristics [ [9] , [10] , [11] , [12] ], optimization [ [13] , [14] , [15] , [16] , [17] , [18] ] and control [ 19 , 20 ] of this technological process.…”