Cavitation erosion damage of pyrophyllite samples reinforced with cordierite, mullite and zirconium-silicate

This study investigates the cavitation erosion resistance of pyrophyllite-based composites reinforced with 20 wt.% of cordierite, mullite and zirconium-silicate, sintered at 1200 ?C. The phase composition and microstructural features of the sintered samples were analyzed using XRD and scanning electron microscopy (SEM). Cavitation resistance was evaluated using the ultrasonic vibratory method with a stationary sample according to ASTM G32, by monitoring the mass loss and surface degradation as a function of exposure time. The results show that the addition of refractory phases with higher hardness significantly improves the cavitation resistance of pyrophyllite. Among the investigated compositions, the sample reinforced with cordierite (P+C) exhibited the lowest cavitation rate (0.145 mg/min) and minimal surface damage, attributed to its compact and homogeneous microstructure that suppresses microcrack initiation and propagation. The samples containing zirconium-silicate (P+Z) demonstrated moderate improvement, while mullite-reinforced samples (P+M) showed the least enhancement due to their elongated grain morphology facilitating brittle fracture. These findings indicate that cordierite is the most effective reinforcing phase for improving the cavitation durability of pyrophyllite-based ceramics, enabling their potential application in hydrodynamic systems exposed to cavitation-induced wear.