Controlling the Microstructure and Texture Using Multidirectional Forging (MDF) to Develop a Low Corrosion Rate Mg Alloy

A new Mg alloy was cast, then extruded, and finally multidirectionally forged (MDF) at 180 degrees C (MDF180) and 300 degrees C (MDF300). The corrosion behavior was evaluated using electrochemical and immersion techniques. The mechanical property was assessed using tension and compression tests. The microstructures were analyzed using optical microscopy, scanning electron microscopy, transmission electron microscopy, x-ray diffraction (XRD), and thermodynamic calculations, while texture was studied by XRD and electron backscatter diffraction. Results indicated that due to grain refinement and good distribution of second phase after MDF, yield strength as well as elongation were improved. The corrosion rates were reduced for MDF180 due to the uniform distribution of the second phase along with uniform distribution of grains. Corrosion rate was more reduced for MDF300 due to dissolution of second phase and elimination of worked grains.