Measurement and determination of dynamic biaxial flexural strength of thin ceramic substrates under high stress-rate loading

Quasi-static and dynamic piston-on-3-ball experiments have been performed on an 8-mol% yttria stabilized zirconia (8YSZ) ceramic material and its doped versions to investigate the effects of the dopants on the biaxial flexural strength of 8YSZ thin substrates. To facilitate the extraction of information from limited number of dynamic experimental results, a new strength model with constant stress-rate as an independent variable was developed based on Tuler and Butcher's concept of cumulative damage. By employing an overall least-squares curve fitting technique, the experimental data were fitted to this model. Results revealed that the alumina (Al2O3) dopant with amount less than 3 mol% and a 3-mol% yttria stabilized zirconia (3YSZ) dopant with amount less than 30 wt% do not change the biaxial flexural strength of 8YSZ thin substrates significantly under both quasi-static and dynamic loading conditions. However, all the materials exhibited clear loading rate strengthening effects.