Microstructural evolution and properties of a Ti-Nb-Ta-Zr-O prepared by high-pressure torsion

Author(s)

da Silva, Murillo Romero ^{[1, 2, 3]} ; Gargarella, Piter ^{[2, 3]} ; Plaine, Athos Henrique ^[4] ; Zeisig, Josephine ^[1] ; Pauly, Simon ^[5] ; Kuehn, Uta ^[1] ; Bolfarini, Claudemiro ^{[2, 3]}

Affiliation

^[1] IFW Dresden, Inst Complex Mat, Helmholtzstr 20, D-01069 Dresden - Germany

^[2] Univ Fed Sao Carlos, Dept Mat Engn, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Sao Carlos, Grad Program Mat Sci & Engn, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[4] State Univ Santa Catarina UDESC, Dept Mech Engn, BR-89223100 Joinville, SC - Brazil

^[5] Univ Appl Sci Aschaffenburg, Fac Engn, Wurzburger Str 45, D-63743 Aschaffenburg - Germany

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 864, MAY 25 2021.
• Web of Science Citations: 0

Abstract

In this work, the Ti-29Nb-13Ta-4.6Zr-0.070 (TNTZO) alloy was processed by high-pressure torsion (HPT), and its microstructure, phase stability, elastic behavior, mechanical properties and deformation mechanisms were determined for samples prepared under different conditions. An increase in beta-phase stability relative to martensite and a significant hardening was observed after severe plastic deformation. The increase in p-phase stability is attributed to the sharp increase in the system's Gibbs free energy that occurs when the alpha `'-laths reach a critical nanometer-size during the HPT processing. This system's Gibbs free energy increase triggers the occurrence of the alpha `' -> beta reverse martensitic transformation. The greater hardness can be related to three factors: microstructural refinement; high dislocation density and stress-induced formation of the omega-phase. Plastic deformation is based on conventional slip, detwinning, stressinduced martensite formation, as well as the reverse martensitic transformation. The reverse martensitic transformation observed during HPT corresponds to a recently discovered mechanism that has not been well addressed in the literature until now. In this paper, this new mechanism is clearly detected and detailed discussed based on a systematic Rietveld refinement, in-depth microscopy, and calorimetry. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys
• Grantee: Claudio Shyinti Kiminami
• Support Opportunities: Research Projects - Thematic Grants