In order to obtain excellent phosphate conversion coatings on the surface of AZ31 magnesium alloy,a novel phosphate process for magnesium alloy by applying magnetic field was developed.The surface morphology,structure and corrosion resistance of conversion coating were studied by SEM,AFM,XRD and Electrochemistry workstation.The results show conversion coatings of AZ31 magnesium alloy can be further formed when the direction of magnetic field is vertical to the surface of magnesium alloy.Conversion coatings ...