[en] The charactr of disordering in alloys of the composition Ni_1-xHfAl, NiAl_1-xHf (x=0.01) was studied and the way to locate minoe additions of hafnium over NiAl sublattices as determined. The models of actual hafnium distribution over NiAl sublattices for equilibrium and nonequilibrium states (quenching from 1573 K) are suggested. Enthalpies of ordering are determined, vacancy concentration is calculated. The results are discussed from the viewpoint of defect formation and stability of NiAl lattice at high temperatures

[en] Some methods of physico-chemical analysis are used to disclose that lanthanum doped NiAl alloys have the type of defects and mechanism of defect formation similar to those stated for intermetallic compound NiAl. Lanthanum introduction into the NiAl lattice hampers disordering processes, in this case 0.2 at.% La substitution for aluminium produces the most strengthening effect (procedure of defect formation displaces at 250 deg to the range of higher temperatures)

[en] Defect formation processes were studied in an NiAl intermetallic compound and solid solutions of nickel based on NiAl (CsCl structure type). The investigation has been carried out with the use of the method of true heat capacity, X-ray analysis, pycnometer density measurements. Comparison of experimental and design ratios of intensities of two X-ray reflections (100) and (110) of the NiAl lattice and the results of pycnometric determinations bear out the vacancy mechanism of weakening of NiAl at elevated temperatures. An analogy has been revealed in the character of variation of thermal capacity, intensity of X-ray reflections, pycnometric density of NiAl alloys containing 51,52 and 53 at. %Ni and of an equiatomic alloy, after different hardenings. A model was suggested for the weakening of non-stoichiometric NiAl alloy, this having served as a basis for calculating the energy of formation of vacancies in alloys rich in nickel

No abstract available

[en] The influence of niobium- and molybdenum small additions on the Fe-Co-Cr system alloy aging has been studied versus the iron, cobalt- and chromium content. The temperature of 898 K is shown to be the optimum one for aging as namely at this temperature a maximum coercive force increase has been observed as compared with other temperatures. Niobium addition improves the alloy magnetic properties, whereas molybdenum stabilizes the high-coercive state. The alloy aging upon various heat treatments is investigated. Two step (913 K+863 K) and three step (1523 K+898 K+863 K) integrations have been studied. It is pointed out on the whole that holding the alloys at integrated temperatures considerably enhances the coercive force of the Fe-Co-Cr system alloys as compared with treatment at a single temperature

No abstract available

[en] Energy variations in Fe-26% Cr-15% Co-1% Nb-1% Al alloy have been studied during the process of aging after different kinds of heat treatment using the method of true heat capacity. During aging in the 600-800 K temperature range, the exothermal effect, which is probably conditioned by the short-distance order formation is indicated. The endothermal effect is fixed in the 800-930 K temperature range. During aging at 1073 and 898 K it is divided into two endoeffects representing different stages of aging of high-temperature solid solution

[en] Kinetics of oxidation of the solid Ni-Al solutions and alloys doped by Cr and Mo has been investigated at temperatures equal 1273, 1373 and 1473 K. To increase of the Al content in the NiAl alloy is shown to result in growth of trend to oxidation. The additions under study have been found to decrease the thermal stability, the Mo addition in particular

[en] Effect of minor additions of 5d-transition elements (Hf, Ta, W) on NiAl resistance to oxidation at 1373 K is investigated. Boundary concentrations of additions stabilizing NiAl properties are found. Interconnection of alloy substructure with heat resistance dange is discussed