Diffusion-bonded transducers for ultrasonic flow measuring and NDT applications

This paper presents results related to design ultrasonic transducers with metallic waveguides on the base of copper and aluminum alloys and diffusion welding and brazing them to the external surface of the pipe wall. This approach provided reliable bonding clamp-on transducers and increasing the accuracy of flow measurements and the resolution in detecting defects. The choice of the Lamb wave modes has been made in accordance with dispersive curves of phase velocities and calculated curves of wave attenuation for the plate loaded by liquid. The appropriate waveguide materials and incident angles have been found on the base aforementioned curves and experiments. The measurements that were conducted with the flowcell having the stainless steel pipe with Din=50mm and wall thickness=5mm and the welded-on transducers on water flow at room temperature confirmed the efficiency of this approach.