Pilot-scale experimental evaluation of induction melting of Ti-46Al-8Nb alloy in the fused BaZrO3 crucible. (January 2019)

• Record Type: Journal Article
• Authors: Chen, Guangyao; Lan, Baobao; Xiong, Fuhao; Gao, Pengyue; Zhang, Hao; Lu, Xionggang; Li, Chonghe
• Is Part Of: Vacuum. Volume 159(2019)
• Page Start: 293
• Page End: 298
• Publication Date: 2019-01
• Subjects: BaZrO3 crucible -- Pilot-scale -- Induction melting -- Ti-46Al8Nb alloy -- Oxygen concentration; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2018.10.050
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Vacuum induction melting in the refractory crucible has been considered as a cost reduction way for the fabrication of TiAl-based alloys. In this study, experimental proof for the feasibility of the pilot-scale melting of Ti-46Al-8Nb alloy was performed in the fused BaZrO3 crucible. Results revealed that the obtained Ti-46 at% Al-8 at% Nb ingot had the oxygen concentration of 0.078 wt%, which was lower than the permitted oxygen concentration (0.1 wt%) of the high-performance TiAl-based alloy. According to the thermodynamic analysis, the oxygen contamination of Ti-46Al-8Nb ingot by the crucible refractory was attributed to the dissolution of BaZrO3 and ZrO2 refractory. Meanwhile, a good macroscopic and microcosmic homogeneity of the Ti-46Al-8Nb ingot was achieved with the refinement time during the melting at 1550 °C for 30s, and the microstructure of Ti-46Al-8Nb alloy was largely composed of lamellar α2 +γ with different orientations and small amount of bulk γ phase. Preliminary results confirmed that the fused BaZrO3 can be considered as an appropriate refractory for the melting of TiAl-based alloys. Highlights: The Ti-46Al-8Nb alloy was fabricated in fused BaZrO3 crucible using vacuum induction melting. A low oxygen concentration (0.078wt%) of the alloy was obtained, the oxygen concentration of this ingot met the requirement of high performance of TiAl-based alloy, which satisfy the 0.1 wt% oxygen concentration. Dissolution of BaZrO3 and ZrO2 was responsible for the oxygen contamination of the Ti-46Al-8Nb ingot.