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