Temperature and strain rate dependence of microstructural evolution and dynamic mechanical behavior in nanocrystalline Ti

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

卷:641

Article

Zhang, Shixiong¹  Wang, Ying Chun¹  Zhilyaev, Alexander P.^2,3  Korznikova, Elena²  Li, Shukui¹  Raab, Georgy I.⁴  Langdon, Terence G.⁵ 

[1] Beijing Inst Technol, Sch Mat Sci & Engn, Beijing 100081, Peoples R China

[2] Russian Acad Sci, Inst Problems Met Supezplast, Ufa 450001, Russia

[3] St Petersburg State Polytech Univ, Res Lab Mech New Nanomat, St Petersburg 195251, Russia

[4] Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia

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

关键词: Dynamic compression;    Microstructure;    Mechanical behavior;    Constitutive equation;    Titanium;   

DOI  :  10.1016/j.msea.2015.06.035

来源: Elsevier

【 摘 要 】

The mechanical behavior of commercial purity titanium with a nanocrystalline (NC) grain size was investigated using split Hopkinson pressure bar tests at high strain rates and over a range of temperatures. The study was accompanied by detailed microstructural investigations before and after compression testing. The results show that rotary dynamic recrystallization operates during compressive deformation at strain rates of 3000 and 4500 s(-1) at temperatures from 298 to 573 K but cells form at 673 K. The dynamic mechanical behavior of NC Ti shows a strong dependence on temperature and strain rate such that the flow stress and the strain hardening rate both increase with increasing strain and decreasing temperature. A constitutive equation is derived to relate the flow stress to the temperature, strain rate and true strain and to predict the yield strength and the peak stress of NC Ti subjected to dynamic deformation at elevated temperatures. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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