2006 年 47 巻 8 号 p. 1886-1889
The slip systems along the ⟨111⟩ direction in bcc iron are investigated by the energy of the generalized stacking fault, or of the stacking fault between two adjacent crystallographic planes of perfect crystals, in order to obtain the knowledge of the slip phenomena in bcc single crystals. For systematic study, the 15 kinds of slip systems along the ⟨111⟩ direction from {110}⟨111⟩ up to {954}⟨111⟩, {972}⟨111⟩ and {981}⟨111⟩ slip systems are taken into account. The energy of the stacking fault is evaluated by the molecular mechanics method with the embedded atom potential of Finnis-Sinclair type as a function of relative displacement of one side of the two half-crystals across the fault plane in the ⟨111⟩ direction. The maximum values of the fault energies for the slip systems whose slip planes have angles of less than approximately 15 degrees to the {110} plane are nearly same as that for the most preferable {110}⟨111⟩ slip system. The maximum value for the {321}⟨111⟩ slip system is the greatest among the currently analyzed 15 slip systems. The maximum value for the {211}⟨111⟩ slip system is in the middle of those for the {110}⟨111⟩ and {321}⟨111⟩ slip systems, and those for the slip systems whose slip planes have angles between approximately 20 degrees and 30 degrees to the {110} plane are close to that for the {211}⟨111⟩ slip system. In general, there is not inverse correlation between the maximum value of the fault energies for the slip system and the interplanar spacing of the considered slip system, although there is inverse correlation between them within the three slip systems which have three lowest index planes, namely, the {110}⟨111⟩, {211}⟨111⟩ and {321}⟨111⟩ slip systems.
