Synthesis of molten-metal corrosion resistant yttria-based refractory by hot-pressing and densification

When the demand for finding new refractory materials which can sustain molten metal at very high temperature becomes imperative, Y2Ti2O7, the main phase precipitated in oxide dispersion strengthened (ODS) steel, has been considered a promising candidate. In this study, ceramic discs of Y2Ti2O7 were firstly sintered from Y2O3 and TiO2 by solid-state reaction and hot-pressing method, and then densified by Hot-isostatic-pressing (HIP) before being employed to fabricate sandwiched structures with aluminum (Al) foils. The phase identification by X-ray diffraction confirmed no reaction between the molten Al and the ceramics, while the micro-structural observation and energy dispersive X-ray spectroscopy results revealed that the densification has improved the resistance of Y2Ti2O7 ceramics against molten-metal penetration. The result of this study should be good reference data for designing for crucible, casting molds.