Microstructure and properties of (1 −  x )La 0.9 Ca 0.1 CrO 3 /x ZrO 2 ( x  = 0–30 wt-%) composites

Abstract

The microstructure and properties of Ca doped lanthanum chromate [La_0.9Ca_0.1CrO₃ (LCCO)] and zirconia (ZrO₂) composites [abbreviated as (1 − x)LCCO/xZrO₂, x = 0–30 wt-%] prepared by solid state reaction method are investigated in this paper whose potential application in heat resistant ceramics are also discussed. The growth and fusion of the LCCO grains are hindered by the ZrO₂ grains, which make the matrix grains refined. In the stable system, it is discovered that the density of the composites decreases, the porosity increases and the decrease amplitude of the bend strength after thermal shock at 600°C reduces with the increasing ZrO₂ content, which results in diminishing the bend strength gradually and enhancing the thermal shock resistance. When x = 10–15 wt-%, the samples show the best thermal shock resistance realising a maximum thermal cycle times of 8. The material with x = 20 wt-% exhibits excellent slag resistance.