A Molecular-Dynamics Model for Thermal Failure of the BCC Crystal. I. The Elastic Constants.
The Physics of Metal and Metallography, Vol. 74, No. 6, 1992 Original Russian Edition Copyright © 1992 by The Physics of Metals and Metallography English Translation Copyright © 1992 by Interperiodica.
A. E. Galashev and I. G. Mukhina
Abstract —The stability of the sodium crystal and its failure mechanism are investigated by the molecular dynamics method. The superheating of the bcc crystal in the model is 0.09 Tm. One approaching the disordering temperature, T*, first the shear modulus, cT11 - cT12, and then cT44 go to zero, whereas cT11 retains a nonzero value even at T*. The bcc crystal begins to fail with the irreversible slip of the particles in the most populated plane (110). In the metastable region, the temperature dependence of the pressure derivatives of the second-order elastic constants, as determined from the calculated second and third-order elastic constants, has a sharp peak position corresponds to the disordering temperature.