Weibull statistical analysis of fracture behavior and Vicker's hardness of yttria ceramics sintered at various temperatures

This study systematically investigated the microstructural evolution of hot-pressed sintered Yttria ceramics by varying the sintering temperature. Mechanical properties, including Vickers hardness, were rigorously assessed to gain insights into the material's response to different processing conditions. Furthermore, fracture toughness was derived from Vickers hardness measurements, and a comprehensive Weibull statistical analysis was conducted to understand the material's failure behavior. Our findings reveal distinct trends in mechanical properties as a function of sintering temperature. Specifically, the Shape and Scale parameters of the Weibull distribution exhibited significant variations in the temperature range where mixed crystalline and glassy phases coexisted. Notably, fracture toughness exhibited a pronounced decline at temperatures favoring the formation of glassy materials. Microstructural observations unveiled intriguing phenomena, including crack splitting and hackle formation, predominantly in the uncrystallized remnants of liquid phase specimens with increased density. The emergence of these fracture patterns underscores the role of microstructural changes within the grain boundaries. When crystalline phase transitions occurred, statistically processed fracture toughness data revealed a mean value of 1.39 +/- 0.071 MPa, providing a robust confidence interval for Yttria ceramics. This research elucidates the complex interplay between microstructural variations and mechanical properties, shedding light on the critical factors influencing the performance and reliability of Yttria ceramics under varying sintering conditions.