Stress Corrosion Resistance of Laser Shock Peening/Microarc Oxidation Reconstruction Layer Fabricated on AZ80 Magnesium Alloy in Simulated Body Fluid

Three types of surface treatments were performed on AZ80 magnesium (Mg) alloy by laser shock peening (LSP), microarc oxidation (MAO), and laser shock peening followed by microarc oxidation (LSP/MAO). The stress corrosion resistance of treated and untreated specimens was carried out using slow strain rate tensile testing at a strain rate of 5 x 10(-7)/s in simulated body fluid. The influence of microstructure on the stress corrosion behavior was analyzed by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and electrochemical measurement. The results showed that the LSP/MAO specimen has a higher stress corrosion resistance compared to the AZ80 Mg alloy substrate, the LSP-treated specimen, and the MAO-treated specimen. The factors improving the stress corrosion resistance of the LSP/MAO specimen are its nanocrystalline material, compressive residual stress, and favorable (0002) basal texture of its reconstructed layer.