Acoustic emission (AE) signals during different contact fatigue damage phases of Fe-based alloy coating were collected. The signals were five-layer decomposed and reconstructed by dB10 wavelet. Characteristics of waveform and frequency of AE signals during fatigue damage were analysed. The results show that continuous type of untreated AE waveform is dominant during crack initiation phase, then mixed type is dominant during crack stable growth phase, and burst type is dominant during crack unstable growth phase. That separation fatigue damage signals from interference waves by wavelet transform was achieved, and fatigue damage signals of improved signal-to-noise ratio were obtained. Distribution of frequency is different during different fatigue damage phases, and the more severe of fatigue damage, the more extensive of frequency distribution and the larger of waveform amplitude in every layers.%采集铁基合金涂层在不同接触疲劳损伤阶段的声发射信号,并采用dB10基本小波对其进行5层小波分解和重构,分析了疲劳损伤声发射信号的波形和频率特征.结果表明:裂纹萌生阶段的原始声发射信号以连续型为主,裂纹的稳定扩展阶段以混合型为主,裂纹的失稳扩展阶段以突发型为主；通过小波变换实现了将疲劳损伤声发射信号与干扰波分离,获得了高信噪比的疲劳损伤特征信息；在不同的疲劳损伤阶段,声发射信号的频率分布各不相同.随着疲劳损伤的加剧,各层的波形幅值呈增大的趋势,并且疲劳损伤频率分布范围也更加的广泛.
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