Atomistic simulation of the influence of pressure on dislocation nucleation in bcc Mo

Molecular dynamics simulations were carried out to investigate the pressure dependence of homogeneous defect nucleation behavior in bcc Mo. The crystal was sheared on the ( 1 1 ¯ 0 ) [ 1 1 1 ¯ ] slip system under different confining pressures. The defect nucleation stress was found to increase as the confining pressure increases. Dislocation loop was nucleated when sheared under hydrostatic compression, while Martensitic transformation was found to occur when sheared under sufficient hydrostatic tension. Atomistic details of the nucleation processes are analyzed and the influence of pressure on the nucleation dynamics of dislocations has been studied. Analysis was made with the help of the energetics of generalized stacking faults when the crystal was deformed statically under different hydrostatic pressure in a highly controlled manner.