The effect of porosity and glassy phase amount of porcelain tiles on ultrasonic velocity

Non-destructive testing (NDT) has been playing critical role in processing, testing and structural evaluation of materials. Ultrasonic testing is a widely used characterization method in non-destructive testing (NDT). The aim of this study is to establish a better understanding how porosity and glassy phase amount of porcelain tiles change the ultrasonic velocity. In this study, the ultrasonic velocity of the tiles was measured by pulse-echo method, A-scan. To investigate the crystalline and glassy phases formed during heat-treatment, tiles were analyzed with X-ray diffractometer (XRD). Additionally, total porosity percentage of tiles was measured with the pycnometer and mean pore size of tiles was analyzed by mercury intrusion porosimeter. It was found that 2% variation of total porosity changed ultrasonic velocity from 4837 m/s to 5055 m/s. When total porosity and mean pore sizes were close to each other, the ultrasonic velocity increased due to the increment of glassy phase