Atom-probe and TEM study of the isothermal ω and secondary α phases in a Ti -10 V -2 Fe -3 Al alloy

Abstract

Résumé. 2014 La décomposition de la matrice 03B2 de l'alliage Ti-10 V-2 Fe-3 Allors de vieillissements à 573 K est étudiée par Microscopie Electronique à Transmission et Sonde Atomique. La combinaison des 2 techniques permet de suivre la formation et l'évolution de la phase 03C9 isotherme ainsi que la précipitation de la phase 03B1 secondaire. Les résultats obtenus conduisent à décrire la décomposition de la matrice 03B2 par un processus non classique en deux étapes.Abstract. 2014 The decomposition of the 03B2 matrix in the Ti-10 V-2 Fe-3 A1 alloy during aging at 573 K is studied by TEM and Atom Probe. The combination of the two techniques allows to follow the formation and the evolution of the isothermal 03C9 phase as well as the precipitation of the secondary 03B1 phase. The 03B2 matrix decomposition is described as a two stage process.

Further Research on Hardenability of Ti-1023 β Alloy Leading to a New DOE

“…Beta solu on treated and water quenched Ti-1023 samples exhibited three different forms of isothermal omega ω i par cles such as nondescript, ellipsoidal and cubical depending on aging temperature and me [4]. Hadjadj et al [38] experimented with alpha-beta solu on treated water quenched Ti-1023 alloy. The atomic probe measurements of the directly aged specimens at a temperature of 300°C showed isothermal omega ω i zones depleted in all alloying elements and a�er a longer annealing me also secondary alpha α s zones with a higher content of aluminium.…”

“…250-400°C for a high hea ng rate 50°C/min. Considering the fact, secondary alpha α s likely precipitates preferen ally at β-ω i interface [38], it might be beneficial to explore the effect of hea ng rate and the volume frac on of isothermal omega ω i for precipita on of secondary alpha α s .…”

Composition of ω-Phase Particles in Ti(Mo) Alloys Studied by Anomalous X-ray Diffraction

“…Hickman studied ω formation in various Ti alloys including Ti-Mo systems and estimated the ω phase composition from changes of its lattice parameter and volume fraction determined by transmission electron microscope [14,15]. One-dimensional atom probe was used to study the formation of the ω particles in Ti-10V-2Fe-3Al (wt.%) alloy [16]. More recently, three-dimensional atom-probe technique was used to investigate the composition of the ω phase in Ti-Mo alloys [3,17], Ti-5Al-5Mo-5V-3Cr (wt.%) alloy [18], Ti-5Al-5Mo-5V-2Cr-1Fe (wt.%) [19].…”