Effects of Severe Plastic Deformation on Mechanical Properties and Corrosion Behavior of Magnesium Alloys

Abstract

Magnesium alloys were produced with extrusion, screw rolling (SR) and multi-directional forging (MDF) processes. Various temperatures were used for SR and MDF. The tensile test was carried out to measure the mechanical properties and immersion test in 3.5 wt% NaCl saturated with Mg(OH)(2) was run to measure the corrosion rate. It was found that the grain size increased gradually with increasing the MDF or SR temperature. The increase in the MDF or SR temperature resulted in decrease in yield strength due to increase in grain size. However, the corrosion rate decreased after MDF and SR. Furthermore, the increase in MDF or SR temperature resulted in more reduction in the corrosion rate due to reduction of galvanic cells by dissolution of the intermetallic phases into the matrix.