Microstructure evolution and mechanical properties response of a TZAV alloy during combined thermomechanical treatments

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2014-12, Vol.619, p.87-94
• Main Authors: Liang, S.X., Yin, L.X., Liu, X.Y., Zhang, X.L., Ma, M.Z., Liu, R.P., Tan, C.L.
• Format: Article
• Language: English
• Subjects: Annealing; Applied sciences; Cold rolling; Cross-disciplinary physics: materials science; rheology; Elasticity. Plasticity; Evolution; Exact sciences and technology; Grains; Heat treatment; Martensitic transformations; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Other heat and thermomechanical treatments; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phases composition; Physics; Production techniques; Strength; Thermomechanical treatment; Thermomechanical treatments; Titanium alloys; Treatment of materials and its effects on microstructure and properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2014.09.071

The microstructure evolution and mechanical properties response of a TZAV alloy during combined thermomechanical treatments containing hot rolling, cold rolling and subsequent annealing processes are investigated. Stress induced martensitic transformation presents after cold rolling and results in transformation from β to α″ phase. Few peaks of ω phase were observed in specimens annealed below 650°C. The microstructure of cold rolled and low temperature annealed specimens are characterized by stretched β grains and fibrous structures. While annealed at 700°C, the specimen has most of approximate granular α grains. The average aspect ratio of α grains increases as the annealing temperature increases. After annealing at 800°C, the stretched β grains recrystallize into approximate equiaxed grains. Tensile testing results showed that the deformed specimens have lower strength than annealed specimens. Hardness results showed the similar trend with strength. Otherwise, the relationships between microstructural parameters and mechanical properties are also discussed in this work. Results show that the strength is greatly dependent on thickness of α grains and content of β phase but has little to do with shape parameters of α grians, conversely, the ductility is related to shape parameters but independent of thickness and content.