Metals, acoustic emission from

There has been some discussion as to whether acoustic signals result from the fracture that occurs when adhesion Is lost at the paint-metal Interface during blistering and cathodic disbonding. In the present study, very sensitive Acoustic Emission measurements have been made In systems exhibiting these types of breakdown. 

Previous work on the application of the acoustic emission technique to corrosion processes has been carried out by Mansfeld and Stocker (i) who were able to show that the detachment of hydrogen bubbles from a polarised metal surface gave measurable signals. 

To differentiate potystyrene from potymethyt methacrylate (PMMA), tisten to their acoustic emission when dropping a test specimen onto a non-metai-lic flat surface polystyrene sounds like sheet metal, PMMA sounds like hard wood. 

Acoustic emission caused by single particle impact is reasonably well understood. It is possible to quantitatively analyze acoustic emission signals to predict particle size. The analysis is based on a deconvolution of the acoustic emission source function from the measured acoustic emission signal. The measured acoustic emission signal V(t) is a convolution of the acoustic source S(t), the propagation function through the metal plate G(t), and the detector response function D(t), where = represents convolution ... 

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