Determination of mechanical anisotropy of magnesium processed by ECAP

Commercially pure magnesium was processed by ECAP from the as-cast condition and also processed by rolling followed by ECAP. The evolution of the microstructure was tracked in both processing routes and compared. The mechanical behavior was evaluated by compression and tensile tests. The results show that ECAP refines the grain structure of magnesium but leads to heterogeneous grain size distribution. The use of an intermediate step of rolling facilitates grain refinement and leads to homogeneous grain structure. Compression tests were carried out at three different orthogonal directions and the results show the development of anisotropy. Significant twinning activity is observed when the material is compressed perpendicular to the die channels. Tensile tests show that ECAP decreases the yield stress and increases the elongation of the material processed by rolling.