Metastable β-Ti alloys are important alloys for the aerospace industry. Understanding the often complex microstructure evolution in these alloys is essential to control their mechanical properties. Hence, we conducted heat treatment experiments combined with in situ electrical resistance measurements to investigate the phase transformation behaviour of a metastable β-Ti alloy, Ti–5Al–5Mo–5V–3Cr (Ti-5553). The results were condensed into a Time-Temperature-Transformation diagram, which revealed three distinct phase transformation regions: ω-phase region, α-phase region, and the likely presence of an α₂-phase region. The phase field ‘nose’ for α-phase formation lies at ~600 °C. Additionally, the results showed that the transition between pseudo-spinodal and isothermal ω-phase-assisted mechanisms for α-phase formation occurs at a heating rate of ~30 °C/min.

中文翻译：

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亚稳态 β-Ti 合金相变的性质：Ti–5Al–5Mo–5V–3Cr 合金的原位研究

介稳 β-Ti 合金是航空航天工业的重要合金。了解这些合金中通常复杂的微观结构演变对于控制其机械性能至关重要。因此，我们进行了热处理实验并结合原位电阻测量，以研究亚稳态 β-Ti 合金 Ti–5Al–5Mo–5V–3Cr （Ti-5553） 的相变行为。结果被浓缩成时间-温度-变换图，揭示了三个不同的相变区域：ω 相区域、α 相区域和可能存在的 α ₂ 相区域。α相形成的相场“鼻子”位于 ~600 °C。 此外，结果表明，用于α相形成的伪棘状和等温 ω 相辅助机制之间的转变发生在 ~30 °C/min 的加热速率下。