The Effect of Oxygen on Phase Equilibria in the Ti-V System: Impacts on the AM Processing of Ti Alloys

Published

July 11, 2018

Author(s)

Greta Lindwall, Peisheng Wang, Ursula R. Kattner, Carelyn E. Campbell

Abstract

The thermodynamic properties of the titanium-vanadium (Ti-V) system are described using the CALPHAD (CALculation of PHAse Diagrams) method. Oxygen is included in an attempt to make the description applicable for "real" titanium alloys for which oxygen always will be a constituent. Combined with previous descriptions of Ti and V oxides, a complete model of the O-Ti-V system is presented. The -transus temperature is calculated to increase with increasing oxygen content whereas the extension of the -Ti phase field into the binary is calculated to decrease, which explains the low vanadium solubilities measured in some experimental works. In addition, the critical temperature of the metastable miscibility gap of the  phase is calculated to increase to above room temperature when oxygen is added to the Ti-V system and the miscibility gap becomes wider covering a larger range of compositions. The effect of oxygen additions on phase fractions, martensite and  formation temperatures are discussed.

Citation

JOM Journal of the Minerals Metals and Materials Society

Volume

70

Issue

9

Pub Type

Journals

Keywords

Titanium-vanadium, oxygen effects, thermodynamics, phase equilibria, Calphad

Citation

Lindwall, G. , Wang, P. , Kattner, U. and Campbell, C. (2018), The Effect of Oxygen on Phase Equilibria in the Ti-V System: Impacts on the AM Processing of Ti Alloys, JOM Journal of the Minerals Metals and Materials Society (Accessed April 25, 2024)