Research on sound absorbing mechanism and the preparation of new backing material for ultrasound transducers

Based on acoustical designing demand of backing material for ultrasound transducer, multiple scattering(MS) theory has been carried out by studying the methods of impedance matching for different layered materials. Typical acoustic properties of the periodic structure in ultrasonic frequency band have been given as well. In order to increase acoustic impedance to match the active materials and improve the absorption performance at the same time, it's a good way to fill metallic particles in the viscoelastic materials. Preliminary test results show that these composites behave good acoustical and mechanical performance. It makes a solid foundation and good prospect for the application of backing material in broadband ultrasonic transducer.