Initial microstructure influence on Ti-Al-Mo-V alloy's superplastic deformation behavior and deformation mechanisms

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

卷:802

Article

Mosleh, A. O.^1,2  Kotov, A. D.¹  Vidal, V.³  Mochugovskiy, A. G.¹  Velay, V.³  Mikhaylovskaya, A. V.¹ 

[1] Natl Univ Sci & Technol MISiS, Leninsky Prospekt 4, Moscow 119049, Russia

[2] Benha Univ, Shoubra Fac Engn, Shoubra St 108,PO 11629, Cairo, Egypt

[3] Univ Toulouse, CNRS, Inst Clement Ader ICA, IMT Mines Albi,UPS,INSA,ISAE SUPAERO, Campus Jarlard, F-81013 Albi 09, France

关键词: Superplasticity;    Superplastic forming;    Titanium alloys;    Microstructural evolution;    Slip bands;   

DOI  :  10.1016/j.msea.2020.140626

来源: Elsevier

【 摘 要 】

Superplastic forming is an effective way to manufacture complex-shaped parts of titanium-based alloys. This paper studies the influence of the initial microstructure and its strain-induced evolution on superplastic deformation behavior and the formability of a titanium-based alloy. Two types of Ti-Al-V-Mo alloy samples having a different fraction of recrystallized grains before the start of the superplastic deformation were studied. The deformation behavior, including strain hardening and strain rate sensitivity of the flow stress, was analyzed in a temperature range of 775 degrees C-900 degrees C and a strain rate range of 10(-5) to 10(-2) s(-1). Strain-induced changes of the microstructure within the bulk of the samples and on the surface of the pre-polished samples were studied during superplastic deformation with a constant strain rate. The dynamic recrystallization and dynamic grain growth in the volume of the samples and the multiple slip bands on the samples' surface were revealed after superplastic deformation. The grain structure evolution and slip bands localization depended on the samples' initial microstructure. The results showed that the samples with an increased fraction of recrystallized grains exhibited better superplasticity and higher quality of the formed parts with a more uniform thickness distribution across the section than the samples with a lower initial recrystallized fraction.

【 授权许可】

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