Research on Ultrasonic Velocity Imaging of Metal Matrix Composites with TIRP Method

In order to evaluate the uniform of SiCp reinforced aluminum metal-matrix composites (MMC) fabricated by powder metallurgy, the ultrasonic velocity imaging was carried out with the method of thickness independent reflector plate (TIRP). Ultrasonic velocity in MMC can be used to calculate the stiffness constants and Yang 's modulus, which are influenced by the volume percentage of SiCp. The TIRP method based on pulse-echo mode was developed to measure very small changes in thickness and velocity wit h a flat and rigid reflector plate behind specimen. Firstly, purpose of ultrasonic velocity ima ging of MMC and basic principle of TIRP were introduced. Secondly, an ultrasonic scan s ystem employed to apply TIRP method was described. Thirdly, the experiments' results of ultrasonic velocity imaging of MMC specimen obtained with TIRP and back surface echo (BSE) respectively were compared and discussed. It is showed that the images gener ated by TIRP have more details than those by BSE. Finally, the factors affecting accur acy and precision in the implementation were considered which may be used to advance the experiment.