Improvement in fatigue resistance performance of corundum castables with addition of different size calcium hexaluminate particles

Cyclic loading of catalytic gasifier lining refractories is one of the most important factors causing fatigue failure. A three-point bending fatigue experiment was carried out to explore the influence of calcium hexaluminate (CA(6)) particle size distribution on the fatigue resistance of corundum castables. Five different castables were damaged by fatigue, the curve of the fatigue strain against the number of cycles has a classical sigmoid shape with three phases: firstly, the strain rate decreases; secondly, it remains unchanged; thirdly, it increases significantly. The maximum strain during fatigue failure is generally greater than in monotonic loading. It has been found that the combination of the grain-matrix plays a critical role in fatigue failure. The fatigue resistance of pure corundum castable decreased significantly at 1100 degrees C. The surface roughness of CA(6) can be effectively combined with the matrix. The fatigue resistance of the corundum based castable where 3-1 mm tabular alumina particles were replaced by he same size of CA(6) particles is best after treatment at either 110 degrees C or 1100 degrees C.