Cavitation erosion resistance of some refractory ceramics

Abstract

Cavitation erosion can be observed as a hazardous phenomenon that has a significant impact on the behavior and lifetime of engineering materials under operating conditions. This phenomenon is a result of fluid flow conditions and can cause the formation of pits and defects, resulting in not only reduced mechanical properties but also a potential risk of hydraulic system components failure and break. The study presents the results of cavitation erosion resistance tests of cordierite-based and alumina-based refractories (low cement high alumina castable). The samples are tested using a standardized procedure, the ultrasonic vibratory method with stationary specimens, for 150 minutes. The samples' degradation is evaluated by measuring and determining the rate of mass and volume loss, as well as the changes in the morphological parameters of defects occurring at the surface. Image analysis is used to determine pit characteristics such are number, average diameter, area, and roundness. The obtained results show that the dominant mechanism for the degradation of the cordierite samples is pit formation, as the number of pits increases for all times of exposure, while for the low cement castable degradation is in the form of grains, with low roundness.