Resistivity study and computer modelling of the isothermal transformation kinetics of Ti–6Al–4V and Ti–6Al–2Sn–4Zr–2Mo–0.08Si alloys

• Published in: Journal of alloys and compounds 2001-01, Vol.314 (1), p.181-192
• Main Authors: Malinov, S, Markovsky, P, Sha, W, Guo, Z
• Format: Article
• Language: English
• Subjects: Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Kinetics; Materials science; Metals; Modelling; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase transformation; Physics; Resistivity; Ti alloys
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(00)01227-5

A resistivity technique is used to study the kinetics of β⇒α+β transformation for Ti–6Al–4V and Ti–6Al–2Sn–4Zr–2Mo–0.08Si alloys at isothermal conditions. The kinetics are modeled in the framework of the Johnson–Mehl–Avrami (JMA) theory. The JMA kinetic parameters for different temperatures and conditions of the above transformation are derived. A good agreement between the calculated and the experimental kinetics is demonstrated Two different mechanisms of α-phase formation depending on the temperature of isothermal exposure are proposed. The calculation of the thermodynamic equilibria showed good agreement with the experimental data for the Ti–6Al–4V alloy and disagreement for the Ti–6Al–2Sn–4Zr–2Mo–0.08Si alloy. Based on the resistivity results, time–temperature–transformation diagrams for both alloys are designed.