TITLE:
Microstructural Modeling of Thermally-Driven β Grain Growth, Lamellae & Martensite in Ti-6Al-4V
AUTHORS:
Matteo Villa, Jeffery W. Brooks, Richard P. Turner, Mark Ward
KEYWORDS:
Titanium, Welding, Rapid Heating, Phase, Alpha, Beta
JOURNAL NAME:
Modeling and Numerical Simulation of Material Science,
Vol.10 No.3,
July
17,
2020
ABSTRACT: The microstructural kinetics of β grain growth in the β field of a
Ti-6Al-4V alloy was studied by a series of controlled heat treatments at
constant temperature rates. Heating rates of 5°C/s, 50°C/s and 500°C/s were
considered, stopping at different peak temperatures. The thickness evolution of
martensitic needles and lamellar α laths, formed on cooling, was also investigated, by soaking the material above
its β-transus temperature and cooling
down at 5°C/s, 50°C/s, 100°C/s and 300°C/s till ambient temperature.
Quantitative microstructural analyses were used to measure the particle
dimensions. The β grain growth
kinetics was reasonably well described by a modified Avrami equation. The thickness
of α lamellae was a function of the
cooling rate and the β grain
dimension in which they nucleated. The martensite needle thickness was shown to
be a function of the cooling rate to which the material was subjected.