Monitoring Fatigue Wear of the Coating Based on Acoustic Emission

Fe-based self-fluxing alloy coating was prepared on 1045 steel by using a supersonic plasma spraying device. Fatigue wear behavior of the sprayed-coating was investigated on a ball-on-disk tester. The process of fatigue wear was monitored by acoustic emission technology. Damage of the coating at different fatigue wear stages was characterized by scanning electron microscopy, and damage mechanism of the coating was investigated. The results show that spalling was the key failure mode of the coating when the rotational speed was 2 000 r/min and the contact stress was 1.8489 GPa. The process of fatigue wear of the coating could be reflected by acoustic emission amplitude and abs-energy, which were composed of elastic and plastic deformation, crack initiation, crack stable existence, crack stable growth and crack unstable growth phase, and the time of crack stable existence determined the fatigue lifetime.