Room temperature single crystal elastic constants of boron carbide

Single crystals of the high temperature ceramic boron carbide have been syn thesized by the optical floating zone method. Room temperature elastic cons tants of a carbon-deficient boron carbide single crystal have been measured using the resonant ultrasound spectroscopy technique. Based upon density m easurements, the single crystal stoichiometry was specified as B5.6C. This crystal has room temperature single crystal elastic constants of c(11) = 54 2.81, c(33) = 534.54, c(13) = 63.51, c(12) = 130.59, and c(44) = 164.79 GPa , respectively. Analysis of Cauchy's relationships, Poisson's ratios, and e lastic anisotropic factors for the single crystal elastic constants indicat es that it is more strongly anisotropic in elasticity and interatomic bondi ng than most solids. Room temperature isotropic elastic moduli of boron car bide show that its bulk, shear and Young's moduli are substantially higher than those of most solids, so that boron carbide belongs to the so-called " strong solids". Its Poisson's ratio is significantly lower than that of mos t solids. (C) 2001 Kluwer Academic Publishers.