Concentration dependence of W-Ta single crystals substructure for different crystallographic orientation of growth

The method of X-ray topography is applied to study the concentration dependence of substructure of W-Ta alloy single crystals with natural carbon impurities for three main orientations of crystal growth: [100], [110] and [111]. The dependence shown for <111> orientation differs essentially from that for two other orientations. This is conditioned by specific features of cellular morphology of {111} crystallization front. The structure formation features resulted from nonstationary nature of the process are revealed under conditions of tantalum monocrystal growth on a tungsten seed crystal and on growing W-Ta monocrystals of variable composition in [100] direction