Multiscale monitoring of interface failure of brittle coating/ductile substrate systems: A non-destructive evaluation method combined digital image correlation with acoustic emission

Abstract

In this paper, we proposed a non-destructive evaluation method combined digital image correlation (DIC) with acoustic emission (AE) techniques, which was used to in-situ monitor interface failure and internal damage of brittle coating/ductile substrate systems under different size scales by bending tests. Measurements of full/local field strain fields by DIC in the segmented coating clearly show typical heterogeneous failure process and successfully clarify several controversial assumptions introduced in theoretical models. AE results effectively reveal the damage evolution of cracking nucleation, propagation and coating spallation of the ceramic coating by combining wavelet transform with traditional parameter analysis under external loads. The conclusions show that there is a good relationship between digital image correlation and acoustic emission signals with the aid of test time during the coating failure, which can be applied to judge cracking formation and coating delamination, and to obtain the most important critical experimental data. As an example, several crucial mechanical properties of a thermal barrier coating system including fracture strength, fracture toughness and shear strength were determined.

In-situ measurements of mechanical and volume change of LiCoO2 lithium-ion batteries during repeated charge–discharge cycling by using digital image correlation

“…It is difficult to obtain the full/local displacement or strain field of cathodes and anodes in LIBs. In recent years, digital image correlation (DIC) technique has been increasing quickly as a powerful tool for non-contact and non-destructive displacement measurement method under different scales and experimental temperatures [22][23][24]. However, to the best of our knowledge, less effort has been devoted to use DIC techniques to in-situ study the evolution of full/local strain fields and volume change in batteries subjected to typical electrochemical operations.…”

Acoustic emission analysis on tensile failure of air plasma-sprayed thermal barrier coatings

“…Different fracture modes would generate different types of AE signals with various AE amplitudes [18] . AE events and amplitudes are generally analyzed by the Fourier or wavelet analysis [16,19,20] . In this paper, AE data were performed by using the discrete Fourier transform to obtain their characteristic frequency spectrums, which ascribe to different fracture sources [21,22] .…”

Fracture characteristics of freestanding 8wt% Y2O3–ZrO2 coatings by single edge notched beam and Vickers indentation tests

“…The post-processing was achieved by the commercially available DIC software (ARAMIS) in order to analyze the evolution of a strain field. The measuring error of strain is less than 0.05% by calibration [26]. The compressive rate of the universal testing machine was set as 0.01 mm/min.…”