Structural Mechanism of Close-Packed Polytypes Formation at Displacive Type Phase Transformation in Alloys

Abstract
Statistics of one-dimensional disordering of polytypes formed under phase transformation of a displacive type of Co-alloys was studied. Discovered polytypes with a short-range order in close-packed atomic layers allowed to propose a mechanism of their formation by noncoherent displacements in the initial polymorphous modification along close-packed planes. Signifiant dependence of polytype structures not only on alioying of an alloy but on the kinetics of a polymorphous transformation is considered as an indirect interaction of atomic layers via the impurities subsystem.