Issue |
MATEC Web Conf.
Volume 321, 2020
The 14th World Conference on Titanium (Ti 2019)
|
|
---|---|---|
Article Number | 12038 | |
Number of page(s) | 9 | |
Section | Microstructure Evolution | |
DOI | https://doi.org/10.1051/matecconf/202032112038 | |
Published online | 12 October 2020 |
Phase transformation sequence of Ti-6Al-4V as a function of the cooling rate
1 Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing, Graz, Austria
2 Institute of Materials Science, Joining and Forming at Graz University of Technology, Graz, Austria
3 voestalpine BÖHLER Aerospace GmbH & Co KG, Kapfenberg, Austria
a ricardo.buzolin@tugraz.at
b desiree.weiss@alumni.tugraz.at
c Alfred.Krumphals@voestalpine.com
d Michael.Lasnik@voestalpine.com
e cecilia.poletti@tugraz.at
The growth kinetics of allotriomorphic α along the prior β grain boundaries and of globular primary α in Ti-6Al-4V during continuous cooling is described. A physical model is developed based on classical nucleation and growth of platelets for the allotriomorphic α. The growth of the primary α is modelled based on the growth of spherical particle immerged on a supersaturated β-matrix. Continuous cooling tests at two different holding temperatures in the α+β field, 930°C and 960°C, and five different cooling rates, 10, 30, 40, 100 and 300°C/min, are conducted to validate the proposed models and elucidate the growth sequence of those α morphologies. Additionally, interrupted tests at different temperatures are conducted to determine the progress of growth of primary α and formation allotriomorphic α during cooling. The size of primary α increases while its size distribution broadens with a decrease in cooling rate. Area fractions of primary α decrease with increasing cooling rate and increasing holding temperature. Moreover, the lower the cooling rate, the thicker the plates of allotriomorphic α. At the beginning of the cooling, growth of primary α, as well as formation of allotriomorphic α plates is observed. The experimental and modelled results show good agreement.
Key words: Ti-6Al-4V / primary alpha phase / allotriomorphic alpha / materials modelling / continuous cooling
© The Authors, published by EDP Sciences, 2020
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.