Load-deflection behavior of fracture toughness testing of ceramics by SEVNB method

Abstract

This paper aims to explore the load-deflection behavior of fracture toughness testing of ceramics by single-edge V-notched beam (SEVNB) method. The fracture toughness of Si3N4, 3Y-TZP, SiC, and 8Y-FSZ ceramics were measured by SEVNB method and single-edge notched beam (SENB) method, respectively. The load-deflection behavior varies with R-curve behavior of the ceramics, the test methods and the loading conditions. Through comparative analysis, the results show that the actual fracture toughness of ceramics by SEVNB method can be determined by maximum flexure load and the notch length at loading rate of 0.05 mm/min in air. The obtained actual fracture toughness values of Si3N4, 3Y-TZP, SiC, and 8Y-FSZ ceramics are 5.2 ± 0.21, 4.5 ± 0.12, 3.2 ± 0.15, and 1.6 ± 0.07 MPa.m1/2, respectively.