Correlation between hardness and elastic moduli of the ultraincompressible transition metal diborides RuB2, OsB2, and ReB2

The ultraincompressible transition metal diborides RuB 2 , OsB 2 , and ReB 2 were synthesized by arc melting the elemental metals and boron under an argon atmosphere at ambient pressure. The hardness and Young’s modulus were measured using nanoindentation with a Berkovich diamond indenter. The bulk modulus and shear modulus were derived based on an isotropic model and then plotted as a function of hardness. A strong correlation is observed between the hardness and shear modulus for these transition metal diborides. © 2008 American Institute of Physics. DOI: 10.1063/1.2946665