Retention of metastable β phase in a two-phase quaternary zirconium alloy. (15th October 2018)

• Record Type: Journal Article
• Authors: Cochrane, C.; Daymond, M.R.
• Is Part Of: Materials & design. Volume 156(2018)
• Page Start: 622
• Page End: 630
• Publication Date: 2018-10-15
• Subjects: Phase transformation -- Zirconium alloy -- Metastable phase -- Quenching -- Dual-phase; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.07.021
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: This study investigates the retention of greater than equilibrium β phase in a two-phase zirconium alloy. We provide experimental data exploring two factors that impact the retention of β phase following heat treatment of a two-phase quaternary zirconium alloy, Zr-3.5Sn-0.8Mo-0.8Nb. Heat treatment temperature and quenching rate are varied to establish a criterion for metastable β phase retention and determine the excess free energy of the metastable phase as a function of solutionizing temperature. It is possible to retain a microstructure with up to 46 vol% β phase at room temperature in this alloy, which has a stable room temperature β phase content of 8 vol%. Graphical Abstract: Highlights: A high β volume fraction can be retained by rapid quenching of Zr-3.5Sn-0.8Mo-0.8Nb. The volume of second phase retained is directly related to quenching rate. High proportions of substitutional solute slow diffusion and promote retention.