Sintering behavior of Y‐doped BaZrO3 refractory with TiO2 additive and effects of its dissolution on titanium melts

Abstract

AbstractIn this study, the sintering behavior of Y‐doped BaZrO3 with TiO2 additive and effects of its dissolution on titanium melts were investigated. In order to overcome the difficulty of Y‐doped BaZrO3 sintering performance, the 0‐5 wt% TiO2 was added into Y‐doped BaZrO3 and its densification was investigated by density analyzer, scanning electron microscope (SEM) and X‐ray diffraction (XRD). Thereafter, the interface reaction between two crucibles (without and with 2 wt% TiO2) and titanium alloys, the thermodynamics and kinetics of dissolution reaction were also investigated. The results showed that Y‐doped BaZrO3 was rarely dense without TiO2 additive and its relative density was just 88%, while after doping 2 wt% TiO2, the relative density was more than 97%. However, with the excessive TiO2(>2 wt%) doping, the secondary phase was observed by SEM and XRD. After melting titanium‐rich alloys (Ti2Ni, 66 mol% Ti) by Y‐doped BaZrO3 crucibles without and with 2% TiO2 additive, the erosion layer of the two crucibles was approximately 4000 and 1700 μm, respectively. It was also found that the dissolved reaction rate was related to the density and grain size of Y‐doped BaZrO3 ceramic; the higher density and larger grain size ceramics can effectively prevent the crucible from being eroded by Ti2Ni melt.