Ultrasonic measurements of Young's modulus and extensional wave attenuation in refractory metal wires at elevated temperatures with application to ultrasonic thermometry

Abstract

Ultrasonic velocity and attenuation measurements have been made by traveling-wave methods on several refractory metals and their alloys. Broad-band pulses centered around 120 kHz were used for extensional waves (and some torsional waves) in wire specimens. Elastic moduli calculated from the velocities decrease with increasing temperature; the slope increases in magnitude at about half the absolute melting point. At the same point, the attenuation begins to increase rapidly and peaks 300--600·C above the breakpoint. These effects are ascribed to absorption in grain boundaries. The transit time versus temperature in rhenium wire has been calibrated for the use of rhenium as an ultrasonic thermometer sensor. Ultrasonic thermometry above 2000·C is an application of the present measurements.

Ultrasonic Velocity and Attenuation: Measurement Methods with Scientific and Industrial Applications

“…The problem of attenuation in refractory metal wires has been studied extensively by the author and his co-workers (Papadakis et al, 1974). Attenuation Problem.…”

Elastic moduli of a ZrCuAlNi bulk metallic glass from room temperature to complete crystallisation by in situ pulse-echo ultrasonic echography

“…These values are much larger (around five times) than the characteristic dimension of the specimen cross section. The condition of very long wavelength is therefore satised and the long beam mode approximation holds, 10) so that E and G can be calculated from ρ, VL and VT according to:…”

“…8) An alternative method is to measure both the longitudinal and transverse sound velocities by ultrasonic echography. 10) Recently, this technique was used to study the changes in Young's modulus for a Zr-based BMG.…”