ELASTIC-CONSTANTS AND ELASTICITY MODULI OF CUBIC AND WURTZITIC BORON-NITRIDE

Elasticity moduli and elastic constants for sphaleritic and wurtzitic boron nitride are calculated and determined by experiment. Numerical v alues are given for single crystals of these materials and polycrystal s of hexanite-R, elbor-R, belbor, kiborite, and other superhard materi als. An approach is suggested for combining hot pressing at ultrahigh pressures and a pulsed ultrasonic technique which may be used to deter mine the elasticity modulus and elastic constants of the majority of r efractory compounds which are difficulty to determine by other techniq ues.