Effect of cold rolling on microstructure and mechanical properties of pure Zr

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 556; pp. 728 - 733
• Main Authors: Yang, Z.N., Xiao, Y.Y., Zhang, F.C., Yan, Z.G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 30.10.2012; Elsevier
• Subjects: Annealing; Applied sciences; Cold rolling; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Cross-disciplinary physics: materials science; rheology; Deformation; Dislocations; Dynamic recovery; Elasticity. Plasticity; Exact sciences and technology; Fracture mechanics; Fractures; Heat treatment; Lamellar structure; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Physics; Production techniques; Pure zirconium; Strain hardening; Strain rate; Strain softening; Treatment of materials and its effects on microstructure and properties; Pure zirconium; Dynamic recovery; Strain softening; Strain hardening; Strain rate; High strain; Work hardening; Ultimate strength method; Dislocation glide; Cellular material; Fracture; Plastic deformation; Subgrain; Dislocation; Plasticity; Nanocrystal; Elongation (mechanics); Cell structure; Annealing; Dynamical recovery; Rupture; Mechanical properties; Stacking fault; Nanostructure; Tensile strength; Cold rolling; High energy; Yield strength; Plastic properties; Microstructure; Fracture mode
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2012.07.056

Though the resultant microstructure and mechanical properties of pure Zr after severe plastic deformation have been studied, the microstructural evolution and the variation of mechanical properties with progressive deformation of pure Zr have not been investigated in detail. Microstructure observation verified that dislocation slip dominated the plastic behaviour of pure Zr during room temperature deformation. With the increase in the rolling reduction (RZr) from zero to 90%, the various microstructural features, e.g. dislocation tangles, dislocation lamellas, dislocation cells or subgrain structure, and nano-crystal grains (∼72nm), etc., successively occurred. Dynamic recovery played an important role on the plastic behaviour of the pure Zr with high stacking fault energy (SFE), which slowed down the work hardening rate during high strain rate rolling deformation and caused strain softening on the pre-deformed specimens during low strain rate tension deformation. The specimens annealed at 450–600°C not only possessed higher ultimate tensile strength and yield strength, but exhibited higher elongation as compared with the undeformed specimen. The fracture mode of all annealed specimens was entirely dimple fracture.