Mechanism study on improving the corrosion resistance of screw rolled Mg–Zn–Ca alloy by nano-MgO addition

Abstract

To reduce the corrosion rate of biodegradable magnesium alloys, n-MgO/Mg–Zn–Ca composites (SR-3ZXM) were prepared using nano-MgO (n-MgO) reinforcement and screw rolling (SR). n-MgO addition and SR refined the grain size and improved the passivation ability and corrosion resistance of SR-3ZXM. After SR, adding n-MgO reduced the corrosion current density of SR-3ZXM to 20.99 μA/cm2. The corrosion rate calculated based on the material weight loss decreased to 0.88 mm/y, which is attributed to the grain size refinement and variation of secondary phase fraction. Thus, n-MgO addition and SR change the corrosion mechanism and improve the corrosion resistance of SR-3ZXM.

Keywords

• n-MgO/Mg–Zn–Ca composite
• Screw rolling
• Microstructure
• Corrosion resistance