Modification of YSZ fiber composites by Al₂TiO₅ fibers for high thermal shock resistance

Yttria-stabilized zirconia (YSZ) fiber composites are highly efficient thermal insulating materials; however, the poor thermal shock resistance limits their versatile applications. In the present study, YSZ fiber was mixed directly with Al₂TiO₅ fiber, which had an extremely low thermal expansion coefficient, to prepare YSZ-Al₂TiO₅ (ZAT) fiber composites by compression molding and heat treatment. The minimum thermal expansion coefficient of the prepared ZAT fiber composites was measured to be 7.74×10^-6 K^-1, which was 26% lower than that of the YSZ fiber composites (10.42×10^-6 K^-1). It was shown that the prepared ZAT fiber composites maintain the integrity after undergoing 51 thermal shock cycles between 1100 ℃ and room temperature. Whereas, YSZ fiber composites burst immediately after only one thermal shock cycle under the same condition. In addition, the ZAT fiber composites also exhibit considerable mechanical and thermal insulating performance.