Projects per year
Abstract
The competitive formation of allotriomorphic α along the prior β grain boundaries, secondary α-phase and the growth of globular primary α is described for the Ti-6Al-4V alloy during continuous cooling. The formation kinetics of the different morphologies of the α-phase is related to the nucleation rate of allotriomorphic α and secondary α as well as with the V supersaturation at the β matrix. A mesoscale physical model is developed for the allotriomorphic α and secondary α based on classical nucleation and growth of platelets. The growth of the primary α is modelled as the growth of a spherical particle embedded in 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/minutes, are conducted. Additionally, interrupted tests are conducted at different temperatures to determine the progress of growth of primary α and formation of allotriomorphic and secondary α-phases during cooling. The size of primary α increases, while its circularity decreases with decreasing cooling rate. The 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 and secondary α. The growth of primary α, as well as the formation of allotriomorphic α plates is observed at the beginning of the cooling stage. The formation of secondary α occurs at last and is nearly negligible for very low cooling rates. The model is able to accurately predict the different α-phase formation behaviours and the obtained results show good agreement with the experimental ones.
Original language | English |
---|---|
Pages (from-to) | 3967-3980 |
Number of pages | 14 |
Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
Volume | 51 |
Issue number | 8 |
DOIs | |
Publication status | Published - 1 Aug 2020 |
Keywords
- Ti-6A1-4V
- primary alpha phase
- allotrimorphic alpha
- secondary alpha
- Materials modelling
- Continuous cooling
ASJC Scopus subject areas
- Metals and Alloys
- Materials Science (miscellaneous)
Fingerprint
Dive into the research topics of 'Modelling the Competitive Growth of Primary, Allotriomorphic, and Secondary Alpha in Ti-6Al-4V'. Together they form a unique fingerprint.Projects
- 1 Active
-
CD-Laboratory for Design of high-performance alloys by thermomechanical processing
Poletti, M. C. (Co-Investigator (CoI)), Buzolin, R. H. (Co-Investigator (CoI)), Wang, R. (Co-Investigator (CoI)), Godavarthy Anantha Venkata, R. K. P. (Co-Investigator (CoI)), Miller Branco Ferraz, F. (Co-Investigator (CoI)), Fortmüller, S. (Co-Investigator (CoI)) & Baumann, G. (Co-Investigator (CoI))
1/05/17 → 30/04/25
Project: Research project