Grain refinement of commercial purity Magnesium processed by Ecap (Equal Channel Angular Pressing)

Abstract

Grain refinement in magnesium is evaluated in the present paper. Equal Channel Angular Pressing is used to process commercially pure magnesium. Processing was carried out at 523 K which is lower than the temperature used in other papers on the literature. The grain structure was evaluated throughout the deformation zone. The low processing temperature prevents significant grain growth. The evolution of the grain structure is compared to a recent model for mechanism of grain refinement in magnesium. The present results confirm the validity of the model.

Analysis of equal channel angular extrusion by upper bound method and rigid blocks model

“…Therefore the estimation of resulting plastic shear during ECAE is a matter of special importance. The total ECAE shear γ S is the sum of the shears on the lines of discontinuities of velocity l 1-2 and l [2][3] (Figure 2a), i.e. …”

“…The Equal Channel Angular Extrusion (ECAE) is a well known method for production of bulk materials with ultra fine grained structure [1][2][3][4] . Despite the simple design of ECAE tool, the homogeneity of material flow, needed pressure and resulting strains are strongly influenced by a number of process parameters like tool geometry, external friction, rheology of extruded material etc.…”