Acoustic emission and lifetime prediction during static fatigue tests on ceramic-matrix-composite at high temperature under air

The present work deals with two types of ceramic matrix composites CMC: SiCf/[Si–B–C] and Cf/[Si–B–C], loaded in static fatigue at high temperature. An acoustic emission-based technique is proposed to predict the residual fatigue life. Indeed, two approaches based on the analysis of released energy are applied. A coefficient denoted RAE is evaluated. Moreover, a cumulative Benioff law commonly used for pre-seismic activations is applied. Under constant stress, micro-cracks are created, which generate elastic waves in a manner similar to earthquakes. The law predicted satisfactorily the time-to-failure of SiCf/[Si–B–C] composite under a constant load.