Texture Control and the Yield Anisotropy of Plane Strain Magnesium Extrusions

Abstract

The textures developed in magnesium, annealed after both hot and cold extrusion under essentially plane strain conditions, have been qualitatively accounted for in terms of the operative deformation modes. It is found that the main features of both textures are explained by the operation of {101¯2} and {101¯1} twinning together with basal slip, but there is an important component of the hot extrusion annealing texture not found in the cold extrusions texture which can only be explained by the action of {101¯0} or {101¯1} slip.The strength of the extruded and annealed material has been studied under various stress systems and initial yield loci have been plotted. Complete crystal orientation distribution functions were used to compute theoretical yield loci for comparison with the experimental results in order to assess the possibility of relating texture and properties in hexagonal metals. It was found that the theory gave remarkably good agreement with experiment. The assumptions made and the terms under which they apply are discussed.