Acousto-Ultrasound Nondestructive Characterization of Rigid Ceramic Hot Gas Filters

Potential of the Acousto–Ultrasound Method to Characterize the Strength of Hot Gas Filter Materials

“…Results by Ellingson et al [4][5][6] show that AU can be applied to several types of ceramic hot gas filters, and that the SWF follows the residual strength of the materials. Also, results from Kathrina and Rawlings 9 indicate a correlation between the strength of sintered MgO and ring-down count, but this has a negative slope, whereas the correlation for hot gas filters has a positive slope.…”

“…This acousto-ultrasound (AU) method [4][5][6] is a combination of traditional ultrasonics and acoustic emission measurements; an ultrasonic pulse or stress wave is sent to the material by a transmitting transducer, and another receiving transducer detects the displacements of the material due to the proceeding stress wave. The wavelength of the transmitted pulse is chosen to produce a Lamb wave that occupies the whole volume of material between the transducers 6 . The wave propagation is affected by scattering from microstructural features like porosity, cracks, and differences in the elastic properties of the phases present, spreading of the wave beam, and absorption and splitting of the beam energy due to mode conversions 7 .…”