Microstructures and Corrosion Behavior of AZ61 Magnesium Alloy Prepared by Extrusion-Shear with Different Die Channel Angles

A new severe plastic deformation process named extrusion-shear (ES) was developed, which combines ordinary direction extrusion and equal channel angular extrusion to realize the interaction of extrusion and shear. Different die channel angles have been designed and manufactured. Microstructures of samples obtained from ES-formed tubes were observed. DEFORM (TM)-3D finite element software was used to simulate the ES process. The corrosion resistances of the fabricated AZ61 Mg alloy samples were investigated by immersion and electrochemical testing. The effects of die channel angles on the corrosion resistance of AZ61 magnesium alloy fabricated by the ES process were studied. Compared with the ES process with a die channel angle of 135 degrees, the ES process with a die channel angle of 120 degrees can induce higher effective strain in the shear deformation zone, and the magnesium alloy prepared with smaller die channel angle has larger electrochemical impedance arc radius, indicating that its impedance is larger. The research results show that samples produced with smaller die channel angles have better corrosion resistances.