Particulate Metal Composites as Backing for Ultrasonic Transducers for Continuous Nondestructive Measurements at...

Area of Science:

• Materials Science
• Acoustics Engineering
• Industrial Nondestructive Testing

Background:

• High-temperature ultrasonic applications require specialized transducers.
• Existing commercial solutions for high-temperature ultrasonic probes are limited.
• The backing material is critical for controlling ultrasonic probe sensitivity and bandwidth.

Purpose of the Study:

• To investigate particulate metal composites as potential high-temperature ultrasonic probe backing materials.
• To evaluate the ultrasonic properties of tin-tungsten and aluminum-tungsten composites.
• To assess the manufacturability of these composite materials for high-temperature applications.

Main Methods:

• Production of tin-tungsten composites via uniaxial pressing with varying tungsten volume fractions.
• Characterization of backing materials using ultrasonic spectroscopy.
• Evaluation of impedance and attenuation properties of the composite samples.

Main Results:

• Tin-tungsten composites exhibited impedance from 25 to 31 MRayl and attenuation from 20 to 191 dB/cm.
• An aluminum-tungsten composite demonstrated impedance of 8-10 MRayl and attenuation of approximately 156 dB/cm at 4.5 MHz.
• The metallic composites possess suitable ultrasonic properties and are relatively easy to manufacture.

Conclusions:

• Particulate metal composites are viable candidates for high-temperature ultrasonic probe backing applications.
• These materials offer a promising alternative to current limited solutions.
• The developed composites meet the requirements for continuous operation at temperatures of 600 °C and higher.