This paper presents a study on acoustic emission (AE) in the bending fatigue process of super-carburized spur gear teeth. Research was carried out on AE signals, AE cumulative event count, AE event count rate, AE cumulative energy count, frequency spectra of AE signals and crack length in the bending fatigue process of eutectoid-carburized SCM415 steel, super-carburized SCM415 steel and MAC14 steel gear teeth. The relation between the AE parameters and the bending fatigue crack propagation as well as the effects of gear materials on the AE characteristics in the fatigue damaging process of the gear tooth were determined. Wavelet transforms (WT) of AE signals of these gear teeth were carried out, and then WT maps of AE signals were examined, Basic data were obtained for the prediction and diagnosis of bending fatigue failure of the supper-carburized gear tooth by means of AE method.
