Determination of Mean Grain Size by Ultrasonic Methods of Tungsten Carbide and Boron Carbide Composites Sintered at Various Temperatures

In this study, the mean grain size of different ceramic-metal composites made from tungsten carbide and boron carbide, have been determined with ultrasonic velocity technique. In addition, electroless coating method was used to coat tungsten carbide samples. Prepared samples were sintered at the different temperatures ranging from 1200 0 C to 1400 0 C in an Argon atmosphere. Powders were placed in a 30mm diameter mold and pressed using a hydraulic press at a pressure of 200 bar. The results were compared to the mean grain size obtained from SEM (Scanning Electron Microscopy). This study has shown a clear dependence of ultrasonic velocity on grain size in composites of boron carbide and tungsten carbide composite. Especially, temperature dependence of mean grain size for tungsten carbide composites can be seen very clearly.