Apparatus for measuring elastic constants of single crystals by a resonance technique up to 1825 K

By holding the rectangular parallelepiped specimen between long, thin alumina buffer rods, we can detect the resonance vibration of a specimen even at temperatures above 1800 K. This new technique, in combination with the theory for the calculation of the resonance frequency spectrum of a rectangular parallelepiped specimen, enables us to determine the high-temperature elastic properties of single-crystal materials. The first application of this new device was to determine the elastic stiffness constants of single-crystal corundum up to 1825 K.