Impact of alumina-based binder on formation of dense strontium zirconate ceramics.

Strontium zirconate (SrZrO 3) is a technical ceramic with potential for refractory applications due to its chemical stability at high temperatures, high melting temperature, and favourable thermal expansion coefficient. Practical use of SrZrO 3 is limited by poor mechanical strength relative to ceramics such as alumina (Al 2 O 3). Sintering of SrZrO 3 with a hydratable Al 2 O 3 binder is investigated as a method for improving mechanical performance. Density, phase composition, thermomechanical properties, and chemical stability in contact with alloys up to 1350 °C are considered. Results are compared with SrZrO 3 samples formed using a traditional polyvinyl alcohol (PVA) binder. SrZrO 3 reacts with alumina during sintering to form SrAl 2 O 4 and ZrO 2. Compared to the PVA binder, the alumina binder drastically reduced porosity in the ceramic, while increasing the indirect tensile strength and fracture toughness. No significant detriment to thermal expansion or chemical stability was found, offering potential for high-temperature applications particularly as a dense crucible material. [ABSTRACT FROM AUTHOR]