Experimental Investigation of the Effect of the Backing Material on the Performance of an Ultrasonic Probe

An ultrasonic transducer (probe) is an important part of an ultrasonic testing system. It comprises of a piezoelectric disk, backing material and matching layer. The process of selection and design of these components for any specific ultrasonic transducer is a challenging task. The backing material should be able to attenuate the ultrasonic waves and to reduce the ringing time of the piezoelectric disk. In this paper, a combination of metal particle (tungsten) and epoxy resin is used as backing material in fabricating transducers. The results show that the performance of the ultrasonic transducer is highly dependent on the characteristics of the backing material constituents. A high resolution or a high energy transducer can be produced just by changing the backing material.