Thermal expansion of vanadium and vanadium hydride at low temperature

Abstract

Interferometric dilatometry has been used to determine the thermal coefficients of expansion for α-vanadium and β-vanadium hydride (31 at.% H) between −160° and 70°C. At the lower temperatures, the coefficients both approximate 6 × 10 −6 per °C. At 70°C, the coefficient is 9 × 10 −6 per °C for the metal, but is nearly double that value for the hydride. The expansions of both materials have been expressed as fourth order polynomials by use of a computer program that minimizes the root-mean-square error. The stress state in the vicinity of a hydride platelet embedded in a vanadium matrix cannot be predicted from the information presently available.