Semi-empirical evaluation of linear coefficient of thermal expansion of metals

The paper considers various semi-empirical methods of the linear coefficient of thermal expansion (CTE), a, calculation. Debye-Grüneisen model was used as a basis and adjusted by taking account of thermodynamic (molar heat capacity, enthalpy) and elastic (Young, bulk, and shear moduli, Poison ratio) characteristics of metals. The formulas for numerical calculations of CTE are derived using: (1) elastic longitudinal modulus, (2) microscopic constants, and (3) enthalpy. CTE were calculated for 25 metals, Ge and Si, and five hexagonal single-crystals in directions perpendicular and parallel to the principle crystallographic axis. Theoretical values of a show good agreement with the experimental ones. (paper)