Compressibility of polycrystal and monocrystal copper: Acoustic-resonance spectroscopy

Abstract

Using a method used mainly by geophysicists for small specimens--acousticresonance spectroscopy (ARS)--we measured the elastic-stiffness constants of centimeter-size copper specimens with rectangular-parallelepiped shapes. The polycrystal consisted of heavily twinned 75-1tm crystallites. From the specimens' macroscopic resonance-vibration frequencies (midkilohertz to low-megahertz), we calculated the least-squares elastic-stiffness coefficients, two and three for the two cases. Using the same specimens, we augmented the ARS measurements with conventional pulse-echo-method measurements. Using rod specimens, we measured the Young modulus E and torsional modulus G, and we calculated the bulk modulus B. The less direct and less familiar ARS method gives the same results as a usual pulse-echo method and a rod-resonance method. The small difference between polycrystal and monocrystal values may arise from mobile twin boundaries that contribute a small reversible plastic strain to the intrinsic elastic strain. We list 16 advantages of the ARS method to measure elastic constants.

First-principles calculations of finite-temperature thermodynamic properties of binary solid solutions in the Al–Cu–Mg system

“…(2) including the equilibrium volume V 0 , bulk modulus B 0 and its pressure derivative B 0 ′, and the enthalpy of mixing ΔE. The present results for fcc Al, fcc Cu, and bcc Cu are comparable with the available experiments [33][34][35][36][37][38][39] and previous predictions [40][41][42]. According to the present calculations, it is found that V 0 and Θ D decrease linearly while B 0 and B 0 ′ increase linearly, with increasing Cu content in fcc, bcc and hcp phases, except for bcc Al 0.5 Cu 0.5 and hcp Al 0.75 Cu 0.25 .…”

An Experimental Evaluation of the Resonant Ultrasonic Spectroscopy Method

“…We plan to conduct more experimental measurements on cubes and rods of the same material. Another method we will use to experimentally evaluate the RUS method uses a Marx Compound Resonator to measure the elastic constants [4].…”

“…Therefore, it is important to experimentally establish the uncertainty of the RUS method. Previously, we have compared RUS with pulse-echo superposition and with other resonance methods [4,5].…”

Thermodynamic Properties and the Equation of State of Copper

“…Для расчета адиабатического модуля объемного сжатия меди использованы экспериментальные данные, представленные в статьях [34][35][36][37][38][39][40]. В большинстве работ измерения проведены до температуры 300 K, и только в двух статьях -при более высоких температурах: 77-800 K [36] и 300-800 K [37].…”