等离子喷涂热障涂层拉伸失效的声发射测试分析

n acoustic emission technique was used to monitor the cracking behavior and fracture process of thermal barrier coatings subjected to tensile loading. Acoustic emission signals were extracted and preformed by fast Fourier transform, and their corresponding characteristic frequency spectrums and dominant bands were obtained to reveal fracture modes. Three different characteristic frequency bands were confirmed, corresponding to substrate deformation, surface vertical crack and interface delamination, with the aid of scanning electronic microscopy observations. A map of the tensile failure mechanism of air plasma-sprayed thermal barrier coatings was established. Using experimental data, the fracture strength and interface shear strength were estimated as 45.73 ± 3.92 MPa and 20.51 ± 1.74 MPa, respectively, which are well agreement with available results..