Corrosion resistance of Al/Al_2O_3 coating prepared by plasma spraying on magnesium alloy

Al/Al_2O_3 composite coating was prepared on AZ31 magnesium alloy by plasma spraying.The polarization curves of magnesium alloy and Al/Al_2O_3 composite coatings were examined by electrochemical test,respectively.The corrosion resistance and corrosion behavior of AZ31 magnesium alloy and the alloy with and without Al/Al_2O_3 composite coatings were studied by immersing corrosion test and 5%NaCl salt spray test.The results show that the corrosion resistance of the sample with Al/Al_2O_3 composite coating on magnesium alloy surface after sealing treatment is better than that of other samples.The corrosion degree of the unsealing treatment coating is more serious than that of magnesium alloy in immersing corrosion test,but it exhibits better corrosion resistance in salt spray test.