Refinement of tungsten microstructure upon severe plastic deformation

The effect of equal-channel angular pressing and high-pressure torsion on the formation of an ultrafine-grained structure in commercially pure tungsten has been studied. The structure was tested by the methods of transmission and scanning electron microscopy using electron backscatter diffraction analysis. The material microhardness depending on the stored deformation has been evaluated. In the samples subjected to severe plastic deformation, the quantitative structure characteristics (the average size of grains/subgrains and misorientation-angle distribution) have been determined.