Density and Thermal Expansion of High Purity Cobalt over the Temperature Range from 140 K to 2073 K

The results of an experimental study of the density and thermal expansion of cobalt over the temperature range 140 K to 2073 K are presented. The measurements were carried out by the dilatometer and gamma-ray attenuation methods with errors of 0.05 to 0.26 pct in terms of density and 0.7 to 7.9 pct in terms of thermal expansion coefficients. The relative density changes were determined during allotropic transformation (0.28 ± 0.04) pct and during melting of cobalt (4.56 ± 0.15) pct. The behavior of the thermal expansion coefficient in the vicinity of the Curie point was investigated. Approximation dependences on temperature for the investigated properties were obtained, and reference tables were calculated. A review of the existing literature data on the volumetric properties of cobalt and comparison with the results of this work were carried out.