Effect of the conditions of high-temperature synthesis on microstructure and mechanical properties if Ni3Al intermetallide
With the help of optical microscopy, scanning electron microscopy, electron microprobe analysis, and X-ray diffraction methods, microstructure and phase composition of Ni3Al intermetallic compounds produced by self-propagation high-temperature synthesis under pressure have been investigated. Intermetallide structure is found to be consists of γ′-phase dendrite grains and g-phase intergranular layers. Plastic deformation of the synthesis product in the course of intermetallide formation leads to growth of anisotropic dendrite γ′-grains as well as occurrence of the zones with modulated (g+γ′) structure in intergranular layers. The structure changes observed are accompanied by increase of the yield stress of the intermetallic compound as well as its ductility decrease.