Non-Destructive Examination for Cavitation Resistance of Talc-Based Refractories with Different Zeolite Types Intended for Protective Coatings

Abstract

In many industrial processes that include fluid flow, cavitation erosion of different engineeringstructures (pumps, turbines, water levels, valves, etc.) during their operation is expected. Metallic,ceramic, and composite materials are usual candidates considered for application in such extremeconditions. In this study, the idea is to synthesize refractory ceramic material based on talc withthe addition of zeolite for utilization as protective coatings in cavitating conditions. Two talc-basedrefractories with zeolites from two Serbian deposits were produced. The behaviors of the samplesin simulated cavitation conditions were examined by an advanced non-destructive methodologyconsisting of monitoring mass loss and surface degradation using image analysis compiled withprincipal component analysis (PCA), interior degradation by ultrasonic measurements, and themicrostructure by a scanning electron microscope (SEM). Lower mass loss, surface degradation level,and modeled strength decrease indicated better cavitation resistance of the sample with Igros zeolite,whereby measured strength values validated the model. For the chosen critical strength, the criticalcavitation period as well as critical morphological descriptors, Area and Diameter (max and min),were determined. A Young’s elasticity modulus decrease indicated that surface damage influenceprogressed towards interior of the material. It can be concluded that the proposed methodologyapproach is efficient and reliable in predicting the materials’ service life in extreme conditions.