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An 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 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 cracking 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 HighlightsWe established several good correlations between AE data and fracture modes.The correlations can be utilized to reveal cracking profile and coating failure.A tensile failure mechanism of coating system was established.Fracture strength of thermal barrier coating has been obtained by this method.The method has a large advantage to study the failure of coating/film materials.

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In-situ morphological evolution of displacement in pouch-type commercial lithium-ion batteries during multiple fifty-five electrochemical charging-discharging cycles was measured via digital image correlation technique. The maximum principal strain on the battery surface reached 0.35% during 55 cycles. The whole volume change analysis of LIBs shows that the maximum volume change rate arrives at 4.27% at the fully 52 nd charging end, and the maximum residual volume change rate is about 2.89% at the 54 th discharging end. The surface morphologies of cathodes and anodes before and after electrochemical cycling were observed by scanning electron microscopy. The elastic modulus of the copper foil in LIBs decrease from as-received 16.7 GPa to 10.6 GPa after 55 cycles by using tensile tests.

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