关键词: 氧化锆, 氧化镁, 致密度, 抗热震性

Abstract: In order to improve the performance of sizing nozzles,MgO stabilized zirconia sizing nozzle material was prepared using ZrO₂ fine powder(d₅₀=3,5 and 8 μm) as the raw material,polyvinyl alcohol aqueous solution as the binder,extra adding different mass fractions (2.0%,2.5%,2.8%,3.0% and 3.5%) of MgO,and heat treating at 1 700 ℃ for 2 h.The effects of the MgO addition on the phase composition,microstructure and properties were studied.The bulk density,the cold compressive strength and the strength retention ratio after 3 cycles of thermal shock of the samples increase first and then decrease with the increase of the MgO addition.When the MgO addition is 2.5%,the comprehensive performance of the sample is the best with 0.75% apparent porosity,5.51 g·cm^-3 bulk density,980 MPa cold compressive strength,and 1 025 MPa cold compressive strength after three thermal shocks.

Key words: zirconia, magnesia, density, thermal shock resistance