Ceramic coated Y1 magnesium alloy surfaces by microarc oxidation process for marine applications

Abstract

The magnesium alloys occupy an important place in marine applications, but their poor corrosion resistance, wear resistance, hardness and so on, have limited their application. To meet these defects, some techniques are developed. Microarc oxidation is a one such recently developed surface treatment technology under anodic oxidation in which ceramic coating is directly formed on the surface of magnesium alloy, by which its surface property is greatly improved. In this paper, a dense ceramic oxide coating, ~20 μm thick, was prepared on an Y1 magnesium alloy through microarc oxidation in a Na 3 SiO 3 -Na 2 WO 4 -KOH-Na 2 EDTA electrolytic solution. The property of corrosion resistance of ceramic coating was studied by CS300P electrochemistry-corrosion workstation, and the main impact factor of the corrosion resistance was also analysed. Microstructure and phase composition were analysed by SEM and XRD. The microhardness of the coating was also measured. The basic mechanism of microarc coating formation is explained in brief.The results show that the corrosion resistance property of microarc oxidation coating on the Y1 magnesium surface is superior to the original samples in the 3⋅5 wt% NaCl solutions. The microarc oxidation coating is relatively dense and uniform, mainly composed of MgO, MgAl 2 O 4 and MgSiO 3 . The microhardness of the Y1 magnesium alloy surface attained 410 HV, which was much larger than that of the original Y1 magnesium alloy without microarc oxidation.

Characterization and corrosion behavior of ceramic coating on magnesium by micro-arc oxidation

“…Therefore, they are preferred in the automotive, electronic and aerospace industry fields [1][2][3][4][5][6][7]. However, the magnesium and its alloys are extremely susceptible to a galvanic corrosion [8], which can further cause severe pitting corrosion on the metal surface resulting in decreased mechanical stability and unattractive appearance [9].…”

Study of MB₃ Mg Alloy by MAO Process in Different Electrolyte

“…MB3 Magnesium alloy has many excellent characteristics, such as, excellent mechanical processing properties, high thermal conductivity and electric conductivity, non-magnetic, non-toxic. It is widely used in portable equipment, mobile phone, marine application [1][2][3][4][5], the magnesium alloys occupy an important place in automotive industry, to achieve the purpose of lightweight.…”