Effects of Na₂WO₄ on the MAO coatings on AZ80

ABSTRACT

The coatings were prepared with different Na₂WO₄ concentration on AZ80 magnesium alloy by micro-arc oxidation. The scanning electron microscopy, energy-dispersive spectrometry and X-ray diffractometer were used to evaluate the microstructure of the coatings. The mechanical properties of coatings were tested by friction and wear tester and microhardness tester. The corrosion resistance of coatings was studied by electrochemical workstation and slow strain rate tensile test. The results show that the addition of Na₂WO₄ can promote the growth of the MAO coating, improve the thickness and continuity of the coating, and make the oxide film dense and smooth. The addition of an appropriate amount of Na₂WO₄ can increase the hardness of the MAO coating, improve the wear resistance and the corrosion resistance of the MAO coating. When the content of Na₂WO₄ was 0.5 g L^–1, the tendency of stress corrosion cracking can be effectively reduced.

KEYWORDS:

• AZ80 magnesium alloy
• micro-arc oxidation
• Na₂WO₄
• microstructure
• property

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The financial support for this research by the National Natural Science Foundation of China under grant number 11702256 is gratefully acknowledged.