AE Characterization of Fracture Behavior in Bioceramics under Simulated Body Environment

Abstract

The effect of simulated body environment on mechanical properties and fracture behavior of bioceramics were investigated. Alumina ceramics, which is a typical bioinert ceramics, was used. Four-point bending tests were carried out in air, refined water and the simulated body fluid in order to investigate the dependence of microfracture process on environments. The microfracture process during the bending tests was evaluated by an acoustic emission technique. Rapidly increasing point of cumulative AE energy was observed before the final unstable fracture. It was understood that the stress at AE increasing point, σ_C, corresponds to the maincrack formation stress in the previous work. These test environments affected σ_C more strongly than bending strength, σ_B. Consequently, it was suggested that the critical stress, σ_C, is available as an evaluation parameter, which is essential as the yield strength in metals, for bioceramics.