Posuvailo V. 3. Evaluation of plasma electrolytic wear and corrosion resistant coating on magnesium alloys

The conversion oxide-ceramic coatings synthesized by the method of the plasma electrolytic oxidizing on magnesium alloys. The high temperature phases MgO and Mg2SiO4 are created on the surface of magnesium alloys, their quantitative content, physical and chemical parameters of synthesis process are investigated, and the relationships between the parameters of treatment and properties of coatings are established. The spectral, the X-ray, the electrochemical, chemical of porosity and optical methods are used. The methods of forming the wear- and corrosion-resistance oxide-ceramic coatings on magnesium alloys are investigated and developed. The parameters of plasma are determined by means of spectral methods. On their basis the thermodynamic calculations for output of plasma-chemical reactions for concentration of products are carried out. Existence of two kinds of pores, and their different type of influence on corrosion resistance are established. The parameters of the process, which allow forming the oxide-ceramic coatings with preassigned microhardness, phase content, thickness, wear and corrosion-resisting, are established. The synthesis parameters with least porosity for oxide-ceramic coatings are selected. The method for closing the through pores by teflon, which result in the wear and corrosion- resistance increasing, is approved.