Alpha phase precipitation in Ti-30Nb-1Fe alloys - phase transformations in continuous heating and aging heat treatments

Author(s)

da Costa, Fernando Henrique ; Salvador, Camilo A. F. ; de Mello, Mariana G. ; Caram, Rubens

• Document type: Journal article
• Source: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING; v. 677, p. 222-229, NOV 20 2016.
• Web of Science Citations: 3

Abstract

Microstructure and mechanical properties of beta metastable Ti-30Nb and Ti-30Nb-1Fe alloys subjected to different aging heat treatments were investigated. Various temperatures and heating rates were employed in order to determine their influence on a phase precipitation. The alloys were characterized by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning and transmission electron microscopy. Several mechanical properties were evaluated, such as Vickers hardness and elastic modulus, and tensile tests were also performed. The results indicate that the addition of Fe reduces the alpha phase precipitation and omega dissolution temperatures, although omega phase was still detected in Ti-30Nb-1Fe aged at 400 degrees C. The addition of Fe caused refinement of alpha phase precipitates, probably due to the higher diffusion coefficient of Fe. As for the influence of the heating rate, 2 and 30 degrees C/min did not cause significant microstructural changes. Finally, alpha phase refinement in Ti-30Nb alloy was favored by aging at 550 degrees C, at a heating rate of 600 degrees C/min. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/13867-2 - Microstructure Evolution and Properties of Metastable Beta Titanium Alloys of the Ti-Nb-Fe Alloys
• Grantee: Fernando Henrique da Costa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/06099-1 - Alpha phase nucleation in metastable beta type titanium alloys in the Ti-Nb-Fe system
• Grantee: Rubens Caram Junior
• Support Opportunities: Regular Research Grants