Investigation of the Effect of Tungsten Used in Backing Materials of Ultrasound Probes on Acoustical Parameters

In backing materials of ultrasonic transducers, filler powders such as tungsten, iron, magnesium and aluminum are generally used. In commercial ultrasonic probes, there are composite support materials consisting of epoxy in which the tungsten particles are joined. Therefore, in the first part of the study, 1 g, 2 g, 5 g and 10 g of tungsten powder mixture were added to the 80-20, 85-15 and 87.5-12.5 ratio epoxy mixtures prepared by weight ratio and the hardness values of these mixtures at the end of the waiting periods have been measured and evaluated. In the second part of the study, the densities, sound velocities and attenuation coefficients of mixtures having different tungsten amounts were measured separately. As a result, it was found that as tungsten amounts increased, densities and attenuation coefficients increased, sound velocities decreased, tungsten showed an acoustic attenuation effect and sound was prevented from advancing in the support material, and when acoustic impedance values were calculated, it was found that acoustic impedance increased as tungsten amounts increased.