ADIABATIC ELASTIC MODULI OF VITREOUS CALCIUM ALUMINATES TO 3.5 KILOBARS

“Pulse superposition” ultrasonic interferometry was used to measure elastic wave velocities and related elastic parameters of four vitreous calcium aluminate specimens at pressures up to 3.5 kbars at 25°C. The values obtained for the bulk (K2) and shear (μ) moduli and for Poisson's ratio (σ) were much higher than those reported for silicate glasses. The bulk moduli for the calcium aluminates, however, fit quite well with the relation between bulk modulus and specific volume per ion pair suggested by Soga and Anderson for 29 glasses. The (dvp/dP) value was highest (8.9×10−3 km/(s.kbars)) for the SiO2‐doped vacuum‐melted calcium aluminate and lowest (6.8×10−3 km/(s.kbars)) for the BaO‐doped air‐melted specimen. The BaO doping seemed to cause anomalous behavior in the shear wave velocity vs pressure relation; the (dv3/dP) value for the BaO‐doped air‐melted specimen was −4.1 ×10−3 km/(s.kbars). The differences in the compressibility at 1 bar and the rate of change of compressibility with pressure appear to be related to composition and melt conditions. The (dK3/dP) values ranged from 4.0 to 4.7 and the (dσ/dP) values from 6.8 to 7.5 ×10−4/kbars. Copyright © 1969, Wiley Blackwell. All rights reserved