Recrystallization behavior of tungsten processed by equal channel angular extrusion at low homologues temperature: Microstructure, hardness, and texture

This work examines the recrystallization behavior of bulk pure tungsten subjected to severe plastic deformation by Equal Channel Angular Extrusion at low temperature. Grain size, morphology, and orientation are examined as a function of subsequent heat treatment temperature. Four temperature ranges are identified wherein the material undergoes recovery, boundary migration, recrystallization, and grain growth. A comparison between this material and warm-worked material is also made, illustrating the effects of stored energy on recovery and recrystallization. Experimentally determined Hall-Petch values agree with previous work. Finally, the plastic deformation behavior of worked and recovered materials are compared with bend test results showing that heat treatment can be used to lower strength while maintaining ductility in heavily deformed tungsten.