Stage formation of quasi-crystals during mechanical treatment of the cubic Frank-Kasper phase Mg 32(Zn, Al) 49

Abstract

Using high resolution electron microscopy, the stage formation of the icosahedral phase during the process of mechanochemical treatment of the cubic Mg 3Z(Zn, Al) 49 crystals has been studied. It has been shown that in the initial stages the icosahedral phase forms locally owing to the formation of rotation defects and disorder of the crystal planes due to the action of plastic deformation. The size of the disordered regions in the icosahedral phase increases with increase in the time of mechanical treatment. An orientation correspondence has also been revealed between the initial cubic and icosahedral phases; this is apparently due to the similarity in the structural designs of the cubic and icosahedral phases.