The role of the ω phase on the non-classical precipitation of the α phase in metastable β-titanium alloys

• Published in: Scripta materialia Vol. 111; pp. 81 - 84
• Main Authors: Zheng, Yufeng, Williams, Robert E.A., Sosa, John M., Wang, Yunzhi, Banerjee, Rajarshi, Fraser, Hamish L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2016
• Subjects: Activation; Alloys; Coherence; Heat treatment; HREM; Interfacial energy; Nucleation; Phase transformations; Precipitation; Titanium alloys; Titanium base alloys; Titanium alloys; Nucleation; HREM; Phase transformations
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2015.08.019

[Display omitted] The metastable β-Ti alloy, Ti-5553, has been heat-treated to permit a determination of the role of the ω phase on non-classical precipitation of the α phase. Thus, samples containing the athermal ω phase have been up-quenched to 600°C. The observations made are consistent with the activation of the non-classical, pseudo-spinodal, nucleation mechanism, with the ω phase playing essentially no direct role. The α/β interfacial structures have been shown to exhibit significant degrees of coherency compared with those in conventional α/β alloys, and implications of this on lowering the interfacial energy, and so the activation for nucleation, are discussed.