Characterization of porosity and defect imaging in ceramic tile using ultrasonic inspections

In this study, three different ultrasonic nondestructive methods (NDT) used to characterize porosity and identify defects in ceramic materials were employed as alternative approaches to conventional systems. A contact ultrasound technique, based on the A-scan, and measurements of the material frequency response were found to be useful for the characterization of porosity in porcelain tiles. Ceramic specimens with two types of simulated defects (a piece of paper and aluminum foil) were prepared and studied. The defects were readily identified in the ultrasonic A-scan and the location depth was measured. The technique, based on air-coupled ultrasound, was shown to be applicable for non-contact detection and imaging of defects in ceramic tiles.