Thermal expansion of transition metal carbides of the fourth-sixth groups

The thermal expansion is studied of monocarbides (MeC) and lower carbides (Me2C) of transition metals of groups 4-6 in the temperature range from room temperature to 2000 and 500 deg C, respectively. The thermal expansion coefficient (TEC) of Me2C reduces on transition from lower carbides of metals of group 4 to carbides of metals of group 6 due to the strengthening of bonds between the metal atoms in the carbides. When considering monocarbides of transition metals ''double periodicity'' has been discovered in the dependence of TEC on the atomic number of the metal component. This is associated with the repulsive contribution to the binding energy from screened Me-Me bonds