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A quantitative approach to the determination of the phase composition in the Al-Mg (Cu)-Li alloys has been developed on the basis of the balance equations of chemical and phase compositions as well as the lattice parameter measurement of the α solid solution. It is shown that, for the Al-Mg (Cu)-Li alloys, the ratio between the fractions of the δ' (Al3Li) and S1 (T1) phases is determined by the ratio between the molar fractions of Li and Mg (Cu). By means of this technique it is shown that in Al-Cu-Li alloys the proportion of δ'-phase is much higher than ternary T1-phase, and the proportion of δ'-phase and a ternary phase (S1) are approximately equal in alloys of Al-Mg-Li system. The equations for the calculation of the contents of the S1 (Al2MgLi), T1 (Al2CuLi) and δ' (Al3Li) phases in the 1420, 1424, 5090 alloys (Al-Mg-Li alloys) and in the 1440, 1441, 1450, 1460, 1461, 1464, 1469, 2050, 2090, 2091, 2094, 2098, 2099, 2195, 2198, 2199, 2297, 8090 (alloys (Al-Cu-Li alloys) are given.

Phase composition, texture and mechanical properties of plates 80 mm thick from Al-2.8Cu-1.7Li-0.5Mg-0.5Zn-0.1Zr-0.06Sc alloy were investigated. It has been found that strength characteristics are maximum in median section (ultimate strength and the yield stress of 570 MPa and 540 MPa, respectively). In 0,25T section (where T is the plate thickness) these quantities make 530 MPa and 490 MPa, and in the short transverse direction of only 490 MPa and 440 MPa. Textural studies showed that on medium layer of a plate 0,3-0,35T thick is observed identical to a matrix and δ'-phase intensive single-component texture with an arrangement of the plane {011} parallel to the plate plane with domination of a "brass" texture component {110} .

The influence of preliminary deformation upon rolling of wedge specimens on the mechanical properties and the structural phase state of Al–Cu–Li alloys are studied by X-ray diffraction and hardness measurements. Strong dependence of the hardening effect upon aging on the reduction upon rolling has been revealed. Deformation weakly influences the hardness and significantly increases the hardening upon aging. Herewith, the hardening effect is nearly absent at the minimum deformation ratio of 1% and increases with its increase. It is demonstrated that the content of T1 phase increases from 2 to 4% in the range of a preliminary deformation ratio of 6–10% and the content of δ' phase is ~17% at a deformation ratio in the range 1‒6% and increases to 18–19% at a deformation ratio of 6–10%. The δ' phase in an alloy contains

The results of studying the phase transformations, the texture formation, and the anisotropy of the mechanical properties in Al–Cu–Li and Al–Mg–Li alloys are generalized. A technique and equations are developed to calculate the amounts of the S1 (Al2MgLi), T1 (Al2CuLi), and δ' (Al3Li) phases. The fraction of the δ' phase in Al–Cu–Li alloys is shown to be significantly higher than in Al–Mg–Li alloys. Therefore, the role of the T1 phase in the hardening of Al–Cu–Li alloys is thought to be overestimated, especially in alloys with more than 1.5% Li. A new model is proposed to describe the hardening of Al–Cu–Li alloys upon aging, and the results obtained with this model agree well with the experimental data. A texture, which is analogous to that in aluminum alloys, is shown to form in sheets semiproducts made of Al–Cu–Li and Al–Mg–Li alloys. The more pronounced anisotropy of the properties of lithium-containing aluminum alloys is caused by a significant fraction of the ordered coherent δ' phase, the deformation mechanism in which differs radically from that in the solid solution.

The heterogeneity of the phase composition, the texture, and the mechanical properties in various zones and directions of plates (thickness T = 80 mm) in a V1461 (Al–Cu–Li) alloy has been studied. It is noted that the strength characteristics are maximal in the median cross section (ultimate strength and yield strength are 570 and 540 MPa, respectively); in the cross section at 0.25T, these values are 530 and 490 MPa, respectively; in the height direction, they are only 490 and 440 MPa. The studies of texture show that an intense one-component texture, which is similar to the matrix and δ' phases, is observed in a medium plate layer of thickness (0.3–0.35)T; the {011} texture plane is parallel to the plate plane with the dominant “brass” {110}〈112〉 texture. Hardness is shown to increase from HRB70 after aging at 120°C for 20 h to HRB85 after three-step aging at 120°C, 20 h + 140°C, 24 h + 150°C, 24 h. It is shown that aging at 120 and 140°C is accompanied by the precipitation of the Θ' phase along with the δ' phase, and aging at 150°C also leads to the precipitation of the T1 phase.

To rare earth metals (REM) or lanthanides are related 14 chemical elements following in the periodic system of D. I. Mendeleev after lanthanum. Most often they are obtained by processing ore, which contains minerals in the form of a mixture of oxides, phosphates, carbonates or silicates of rare earth metals, as well as close to them in properties thorium, yttrium, scandium, titanium, niobium and tantalum.

The effect of a structural type (lamellar, fine, gradient) and additional surface alloying with hydrogen on the diffusion bonding of titanium alloy VT6 samples is studied. It is shown that the surface alloying of VT6 alloy parts with hydrogen allows one to decrease the diffusion welding temperature by 50–100°C, to obtain high-quality pore-free bonding, and to remove the “structural” boundary between materials to be welded that usually forms during welding of titanium alloys with a lamellar structure.

Special features of formation of structure of diffusion joints of a NiTi-base alloy with titanium alloy VT6 are studied. It is shown that diffusion welding produces a transition zone due to the diffusion of nickel and aluminum from the joined alloys. The presence of this zone lowers the mechanical properties of the joints.

The effect of high-temperature heating (1100°C) of semiproducts from TiNi-base alloys melted by different methods and containing different volume fractions of Ti2Ni intermetallic phase on the structure and functional properties is investigated. The results obtained are used to study the possibility of application of such high-temperature methods of treatment as diffusion welding to semiproducts from TiNi-base alloys.