Preparation of ZnAl2O4 and its effect on fatigue resistance of alumina castables

Abstract

Refractories subject to loading and unloading repeatedly because of physical effects and thermal stress attack in the service process, which is an important issue shortening the service life of the thermal equipment. Therefore, researches of predicting the service life of refractories under cyclic loading have the guiding significance. The present work investigated the synthesis of ZnAl2O4 and discussed its effects on the alumina castables. The results show that the optimized generation temperature of ZnAl2O4 phase is 1400°C and the hysteresis loop in the curves of cyclic loading reveals a general trend of first sparse and then dense. The cycle times of the specimen with 3 wt.% ZnAl2O4 is 50 times, and the time from starting to loop to fracture is about 4300 s. The fatigue resistance of the specimen with 3 wt.% ZnAl2O4 is superior to ZA-0 and ZA-1.5. The new method of cyclic loading was innovatively adopted in refractories, which provide data and theoretical support for the thermal shock evaluation methods.