Mechanical properties and microstructural evolution of nanocrystalline titanium at elevated temperatures

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:669

Article

Shahmir, Hamed¹  Pereira, Pedro Henrique R.¹  Huang, Yi¹  Langdon, Terence G.^1,2,3 

[1] Univ Southampton, Fac Engn & Environm, Mat Res Grp, Southampton SO17 1BJ, Hants, England

[2] Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA

[3] Univ So Calif, Dept Mat Sci, Los Angeles, CA 90089 USA

关键词: High temperature behavior;    High-pressure torsion;    Nanostructured materials;    Severe plastic deformation;    Titanium;   

DOI  :  10.1016/j.msea.2016.05.105

来源: Elsevier

【 摘 要 】

An investigation was initiated to study the mechanical properties and microstructural evolution of nanocrystalline titanium in the temperature range of 473-923 K after processing by high-pressure torsion (HPT) under a pressure of 5.0 GPa for up to 10 turns. The results show there is a significant improvement in both the tensile strength and the ductility in nanocrystalline Ti by comparison with coarse-grained (CG) Ti at elevated temperatures. The strength of HPT-processed Ti drops to that of CG Ti at temperatures above 773 K because of grain growth. An investigation of the mechanical behavior at elevated temperatures reveals an increasing-decreasing-increasing trend in the elongations to failure with increasing temperature. An elongation of > 130% was achieved both at 673 K and above 773 K for the HPT-processed samples and this was significantly larger than for the CG Ti. The highest measured elongation was similar to 200% for the HPT-processed sample tested at 923 K. A good combination of strength and elongation to failure was achieved in the temperature range of 573-773 K after HPT processing. (C) 2016 Elsevier B.V. All rights reserved.

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