|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Titanium Technology
||Grain Boundary Segregation and Its Implications Regarding the Formation of the Grain Boundary α Phase in the Metastable β-Titanium Ti–5Al–5Mo–5V–3Cr Alloy
||Stoichko Antonov, T.S. Prithiv, Zachary Kloenne, Rongpei Shi, Yufeng Zheng, Hamish Fraser, Baptiste Gault
|On-Site Speaker (Planned)
We investigated the origin of the deleterious grain boundary ⍺ phase formed during the aging of the β-titanium alloy, Ti–5Al–5Mo–5V–3Cr–0.5Fe (wt.%). We probed the composition of different grain boundaries from the as-quenched β condition and after heating and aging using correlative electron microscopy and atom probe tomography. Our analysis reveals strong segregation of some α-stabilizing elements along with a depletion of β-stabilizing elements. The thermodynamic calculations, based on the measured grain boundary compositions, indicate that the segregation significantly increases the chemical driving force for α nucleation upon aging. Subsequently, multiple α precipitates nucleate along the grain boundary during heating to the aging temperature, and conglomerate during the aging. This work provides essential insight into the formation of the undesired grain boundary ⍺ layers along prior-β grain boundaries in metastable β-Ti alloys and paves the way for microstructural engineering of these alloys with enhanced mechanical properties.
||Titanium, Phase Transformations, Characterization