Experimental investigation and thermodynamic calculation of the Al-rich corner in the ternary Al-Ti-V system. (5th February 2017)

• Record Type: Journal Article
• Authors: Li, Qian; Chen, Zi-Wei; Luo, Qun; Li, Bao-Wei
• Is Part Of: Materials & design. Volume 115(2017)
• Page Start: 339
• Page End: 347
• Publication Date: 2017-02-05
• Subjects: Al-Ti-V alloys -- Intermetallics -- Phase equilibria -- Thermodynamic modeling -- (Ti, V)Al3; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.11.047
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Vanadium was added into Al-Ti based alloys to improve the intermediate temperature ductility and refine the grains. However, the change of phase relations and phase transitions resulted from the V addition has not been fully understood. In this study, the phase equilibria in the Al-rich corner of Al-Ti-V system were investigated using X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer and differential scanning calorimeter. To validate the phase relations, five Al-rich key alloys were prepared and annealed at 600 °C and 700 °C for 360 h respectively. The results indicated that two three-phase regions and three two-phase regions exist in the Al-rich corner at 600 °C. And one three-phase region and four two-phase regions are stable at 700 °C. The EDS results showed that the solubility of V in TiAl3 can vary from 2.8 at.% to 27.0 at.%, which results in a solid solution phase (Ti, V)Al3 . Based on the isothermal phase equilibria at 600 °C and 700 °C and the invariant reactions determined in this work, the model parameters of (Ti, V)Al3 were optimized and a new thermodynamic description of Al-Ti-V system was obtained. Comparing the calculated results with the experimental data, a good agreement was reached. Graphical abstract: Highlights: The Al-Ti-V system was experimentally investigated using equilibrated alloys. The phase transitions in the alloys of Al-rich region were determined. A thermodynamic description of Al-Ti-V system was developed using CALPHAD approach.