Controlled crystallization and the structure of an eutectic nickel-niobium carbide alloy

Methods of light and scanning electron microscopy are used to study structures of the directionally crystallized eutectic Ni-10 % NbC alloy obtained by zone electron-beam melting in a crystallization rate interval from 0.5 to 12.0 cm/h with 100 K/cm temperature gradient in the melt near the crysrallization front. Trifolia in combination with fibres are basic structural elements of alloys of this kind. The dependence of distances between trifolium centers (lambda) on crystallization rate (V) is described by the expression lambda2V=1.16x10-5 cm3/h. Structural carbide phase defects are studied, induced by instability of directed crystallization parameters