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[en] For heat resistant nickel base alloys (EhI437B, EhP741, EhP962, ZhS6KP) with a volume share of hardening intermetallic γ-phase lying in the range of 15-60% are taken as examples to examine the effect of high temperature deformation and recrystallization on the nature of resulting microstructure. It is established that the most essential factor affecting the formation of microstructure is the relationship of deformation temperature and/or recrystallization annealing temperature to the temperature of complete dissolution of γ-phase (T_c.d.γ) in the alloy. At temperatures above T_c.d.γ (a single-phase γ-state of the alloy) dynamic recrystallization on deformation and static recrystallization on post-deformation holding at heat or repeated heating are progressing. At temperatures below T_c.d.γ (two-phase (γ+γ')-state of the alloy) the nature of the structure resulting from deformation and recrystallization is dependent on a γ'-phase volume share at a given temperature

[en] ANKB-2 ampholyte containing copper, nickel and yttrium was investigated by infrared spectroscopy. It was esrtablished in result of analysing obtained spectra that copper, nickel, yttrium interact both with carboxyl ampholyte group and heterocycle nitΩgen with formation of coordination compounds of chelate type

[en] Relationships of dislocation structure evolution to morphological changes of gamma'-phase at the secondary and transient stages of creep at 1000 deg C have been investigated theoretically and experimentally for heat resisting nickel base alloys. The dislocation structure which is formed at interphase boundaries under deformation of two-phase alloys is under consideration along with dislocation-induced stress fields. These latter are shown to be reponsible for formation of lamellar structure of the initial creep stage and to promote perfecting of lamellar shape at the secondary stage in the alloys with negative lattice discrepancy

[en] The stability of the monocrystal microstructure in dependence on the deformation (active tension, creep rate, shift under pressure) and postdeformation thermal effects is studied by example of three heat resisting nickel alloys (EhI437B, ZhS32 and VKNA-type) with the voluminous share of the strengthening γ-phase ∼15-95%. Formation of the substructure due to the dynamic recrystallation was observed by the high-temperature deformation in the single-phase γ-area (the EhI437B alloy, active tension) in the monocrystals. Deformation in the two-phase (γ+γ) area leads to formation of significantly different structures, depending on the temperature and way of deformation

[en] On monocrystals of the KhN77TYuR alloy of three different orientations extented in the 1373-1473 K temperature range up to various strain degrees, peculiarities of high temperature softening including dynamic recrystallization have been studied. The structure of dynamically and postdynamically recrystallized grains is metallographically investigated. Hardening curves are plotted in true coordinates for monocrystals of all orientations. A strong effect of deformation temperature and orientation on the beginning of dynamic recrystallization is pointed out. The criterion of the beginning of dynamic recrystallization independent of the monocrystal orientation is shear stress occuring in the slip plane

[en] By means of electron microscopy, X-ray structure analysis, measurement of microhardness one investigated into the effect of the moderate (under creeping) and the intensive (shift under pressure) deformation on the structure and hardness of <001> monocrystals of nickel-base superalloy containing 0.16%C, 19% γ-alloying elements (Cr, Co, Mo, Re), 21% γ' - and carbidoforming elements (Ta, Nb, V, W, Al). One studied the peculiarities of recrystallization and phase transformations in the alloy upon various type deformation and heating. Deformation under creeping at 1000 deg C was determined to result information of lamellar γ/γ' - structure. At subsequent heating up to 700 deg C extra amount of γ'-phase was formed with no variation of dislocation structure. Under 1100-1200 deg C γ'-lamellas were dissolved and the dislocations were redistributed. Under 1220 deg C and higher in the volumes with complete dissolving of γ'-phase the alloy was crystallized. Shift under pressure at room temperature in monocrystals with lamellar and cubic γ'-phase resulted in variation of morphology of hardening particles. Recrystallization took place in gamma-phase at the absence of γ'-particles upon both the moderate and the intensive deformations

[en] Tantalum and niobium base MC primary carbides linked with matrix via cubic orientation ratios are precipitated in monocrystals of nickel base high-temperature high-alloyed superalloy with <001> growth axis orientation and 0.16% carbon content at crystallization alongside with main strengthening γ'-phase. MC carbides at crystallization, thermal treatment and creep test undergo transformations with formation of M₂₃C₆ and M₆C globular carbides

[en] Short communication

[en] The structure and strength properties of monocrystals with the growth axis <100> of two heat resisting nickel-base alloys after various modes of high-temperature treatment of the melt have been investigated. By the methods of electron microscopy, X-ray diffraction analysis and metallography, the influence of temperature of the melt on structural perfection of the monocrystals, parameters of cellular-dendritic structure, morphology and dispersion of strengthening γ'-phase, degree of coherence in γ/γ' phase interface and their interrelation with long-term rupture strength of the alloys studied, has been analyzed