Effect of Pressure and Temperature of Solution Treatment on the Microstructure and Corrosion Resistance of AZ91D alloy

As-cast AZ91D magnesium alloy was solid dissolved at atmospheric temperature under different pressures (room pressure1, 2, 3, 4, 5 and 6 Gpa) and under high-pressure (6 Gpa) at different temperatures (atmospheric temperature, 200, 400, 600, 800 and 1000 degrees C). The microstructures of the products were characterized by optical microscope and their corrosion resistance was investigated. The results show that increasing the solution pressure at atmospheric temperature has no obvious effect on the microstructure of AZ91D, but decreases the corrosion resistance. Increasing the solution temperature under the high-pressure can obviously improve the microstructure of the alloy, and markedly increases the corrosion resistance, especially over 400 degrees C.