Abstract
The indentation fracture (IF) method is necessary for evaluation of fracture toughness of ceramics due to its simple test procedure and low sample size limitations. However, the conventional method is inferior in measurement accuracy, has many calculation formulas, and there is no unified view as to which formula should be used, which hinders international transactions. We developed a technique to improve the reliability of the measured values by increasing the magnification of the microscope to reduce the crack length reading error. Using this technique, we were able to select the optimal calculation formula. The round robin tests were conducted with the cooperation of 18 domestic and overseas testing institutions, and the reproducibility of the developed method was verified. Backed by these back data, we were able to publish the international standard.
