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

• Published in: International journal of refractory metals & hard materials Vol. 83; p. 104966
• Main Authors: Levin, Z.S., Brady, B.G., Foley, D.C., Hartwig, K.T.
• Format: Journal Article
• Language: English
• Published: Shrewsbury Elsevier Ltd 01.09.2019; Elsevier BV
• Subjects: Bend tests; Energy recovery; Equal channel angular extrusion; Grain growth; Grain size; Heat treating; Heat treatment; Homology; Internal energy; Materials recovery; Morphology; Plastic deformation; Recrystallization; Recycled materials; Tungsten
• ISSN: 0263-4368; 2213-3917
• DOI: 10.1016/j.ijrmhm.2019.05.012

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. •Post-processing heat-treatments have been performed on severely plastically deformed tungsten with microstructure, texture and hardness characterization•EBSD analysis illustrates changes in texture of heavily worked tungsten at various heat-treatments.•Post-processing heat treatment have been identified which significantly reduce strength while retaining high ductility of ECAE processed tungsten at low homologous temperatures.•Grain size and Vickers hardness data indicate a Hall-Petch type relationship between of a large range in grain sizes sub micron to >10 μm.