| With the wear-resistant coating widely used in cylinder, detection and evaluation of coating quality, and predicting the service life of the coating become as a key issue. The traditional method is only carried on for part of coating, but the majority of defects exist in the face of the whole work. Therefore, how to evaluate the quality of the whole coating and the combination, which are keys that should be solved in this paper.This article has developed a set of detection system and evaluation method to cylinder liner wear-resistant coating defect. The device and acoustic emission (AE) testing equipment are integrated to simulate the process of coating damage under the condition of external load. Different loads are forced on coating to simulate the destruction which can obtain AE parameters and signals. Firstly, the exact location of AE source is determined by using wavelet transform technique on the waveform signal to decompose its frequency band, which is based on AE source location technique. The principle of dual-probe's linear positioning and theory of loading system's uniform movement are integrated which achieves plane locations of defect sources. Secondly, Diagrams of AE parameters are researched under different loads and different plating. Results show that the system can evaluate the quality of different coating. At last, AE signals of quality of coating are analyzed by using wavelet analysis theory, which is based on AE recognition technique of coating's damage modes. Study shows that there are great differences of energy signals between coating's abnormal wear and damage. The energy signals of coating's abnormal wear mainly concentrate in the low-frequency, but damage's mainly concentrate in the high-frequency.The research shows that this system can evaluate the quality of coating through analyze AE parameters and AE signals, and has advantages of small device, rapid detection and high accuracy.
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