Inspection of ceramic tiles with ultrasonographic non-destructive testing method

Quality control at tile production is a difficult and extensive lobour force process. The most important step of quality control consists of achievement of desired density and strength. Traditional density test method conducts chosen representative samples of production and takes 8 hours. Improvement of quality and interfere to the production process immediately, it is necessary to shorten this test time and inspect more samples. From this point of view, in this study ultrasonic test method was investigated as one of non-destructive testing method. Tiles prepared by using porcelain tile granules were sintered in different temperatures and then changing of ultrasonic time and velocity with bulk density, apparent density, apparent porosity (%), water absorption (%) inspected via contact A-scan ultrasonic testing. Without necessity of traditional test methods, by using obtained ultrasonic velocity-bulk density, ultrasonic velocity?apparent density, ultrasonic velocity?apparent porosity (%), ultrasonic velocity-water absorption (%) calibration plots and only ultrasonic velocity measurement other properties (densities, porosity, water absorption) can be determined. In the samples containing drilled holes, because of the energy decreasement of induced ultrasonic velocity, a decreasement in the intensity of ultrasonic peak was observed. Various defects were inspected by using water immersion ultrasonic C-scan, detailed information was obtained about defects? size and place. By measurement of scanning electron microscope (SEM) characterization images about the distance between the defect and the surface supported by defect place information obtained with C-scan ultrasonic. Non-contact ultrasonic C-scan analyses held abroad yielded different results for various defects. Ultrasonic time measurements with non-contact ultrasonic test method was tried with current laboratory equipments but since the non-contact transducers used did not conduct ultrasonic signals, measurements could not be held.