Biaxial Flexural Strength of Technical Ceramics Using a Miniaturized Ball‐on‐3‐Ball Fixture

ABSTRACT

A process for developing statistically relevant mechanical properties of advanced, high‐value ceramics using smaller, miniaturized, specimen volumes is crucial due to the challenges associated with the manufacturing and cost challenges associated with larger samples. In this study, a miniaturized ball‐on‐3‐ball (B3B) method was designed to determine the transverse rupture strength (TRS) of miniaturized right‐cylindrical technical ceramics. Two fixture configurations were tested and compared, and an optimal fixture design is demonstrated. Three technical ceramics were tested to validate the miniaturized B3B fixture, including commercially available alumina (Al ₂ O ₃ ), magnesia partially stabilized zirconia (MSZ), and yttria partially stabilized zirconia (YSZ). A statistically relevant number of samples ( N > 59) for each material were tested to allow for an accurate Weibull statistics assessment. TRS testing of Al ₂ O ₃ , MSZ, and YSZ resulted in characteristic strengths of 437, 1168, and 1380 MPa, respectively. Weibull moduli of Al ₂ O ₃ and MSZ were both determined to be nearly 12, whereas the Weibull modulus of YSZ was determined to be 7. The TRS and Weibull data for Al ₂ O ₃ , MSZ, and YSZ obtained in this study yielded comparable results to prior results using larger‐volume samples. Grain morphology was quantified via electron microscopy.