The effect of irradiation with 20 keV argon ions on the mechanical properties, structure, and phase composition of quenched and then naturally aged, hot-pressed profiles (6 mm thick) from the D16 alloy of the Al-Cu-Mg system has been studied. It was found that short-term irradiation with Ar+ ions (E = 20 keV, j = 200 μA/cm 2 , F = 1×10 16 cm -2 , irradiation time 8 s) leads to transformation of the microstructure and phase composition of the alloy. The coarsening of the initial subgrain structure occurs near the sample surface. Both in the surface layer and at a distance of ∼ 150 μm from it, partial dissolution and fragmentation of complex intermetallic compounds of crystallization origin located along grain boundaries are observed, as well as a decrease in the size and change in the morphology of Al 6 (Fe, Mn) intermetallic compounds of crystallization origin are observed too: the distribution density of lamellar precipitations decreases, and equiaxial precipitations disappear. Under the influence of irradiation, the decomposition of the supersaturated solid solution is activated with the formation of a more stable phase S’. As a result of ion-beam treatment in this mode, the plasticity of the alloy increases while maintaining the strength properties.

The effect of accelerated Ar + ion beams with an energy of 10 keV on the microstructure and phase composition in 1469 alloy (Al-Cu-Li-Ag-Mg-Zr-Sc) initially subjected to severe plastic deformation (SPD) has been investigated by transmission electron microscopy. Irradiation has been found to result in the formation of a predominantly recrystallized nanocrystalline or fully recrystallized submicrocrystalline structure in the alloy, depending on the ion fluence. The irradiation liquidates the banded structure found in the alloy after SPD. Therefore, the structural elements (nanofragments, nanograins, submicrocrystals) are distributed uniformly in the volume of the irradiated sample. In addition, irradiation increases the volume fraction and the size bimodality of heterogeneously-generated T 2 -phase particles. The mechanism of nucleation and growth of excess phases has been proposed. The structure changes at a higher rate than it does during a long low-temperature annealing process, and structural changes are observed at a distance of ∼200 μm from the surface, which considerably exceeds the projected ion range (∼ 10 nm).

The effect of 20-40 keV Ar + ion irradiation on the mechanical properties and structural and phase state of hot-pressed profiles 6 mm thick made of an V95 alloy (Al-Zn-Mg-Cu system) after artificial aging has been studied. Irradiation (without causing heating) at fluences of 2∙10 15 cm −2 and 1 ∙ 10 16 cm −2 has been revealed to increase the relative elongation by 5%, without changing the strength characteristics. Electron microscopy examination has showed that irradiation has an effect on the state of the subgrain structure of the alloy. Irradiation at these fluences results in partial enlargement of the subgrain structure, and at higher fluence of 9.4∙ 10 16 cm −2 it completely transforms the structure into coarse-grained one. At a distance of 150 μm from the irradiated surface, there is a slight increase in the subgrain size. The irradiation changes the morphology of Al 6 (Fe, Mn) intermetallic compounds in both the surface layer and the sample volume; namely, it sharply decreases the bulk density of lath-shaped intermetallic compounds and increases the density of the equiaxed ones. The degree of influence depend on the irradiation mode.

Based on results of structural analysis and mechanical tests of initially cold-rolled 1-mm-thick sheets made of 1441 aluminum alloy, the efficiency of radiation annealing was proved, which was used instead of standard furnace annealing. It has been established that exposure of cold-deformed metastable alloy 1441 of the Al-Li-Cu-Mg system to beams of accelerated Ar+ ions (E = 20-40 keV) initiates the process of explosive rebuilding of the initial cellular dislocation structure in them with the formation of subgrains (at fluences of similar to 10(15)-10(16) cm(-2); a corresponding irradiation time from similar to 1 to 10 s; T <= 130 degrees C), as well as recrystallization and grain growth processes (at fluences of 1.75.10(16)-2.10(17) cm(-2)). In the course of irradiation, a reduction in size and partial dissolution of Al8Fe2Si and Al3(Z)r coarse intermetallic particles formed during crystallization and the formation of theta' (Al2Cu) and S-1 (Al2LiMg) strengthening phases also take place. It was established that the ion irradiation-induced fast processes occur in the whole volume of 1-mm-thick samples far beyond (by factor similar to 10(4)) an Ar+ projected range at temperatures significantly below (by 100-200 degrees C) the temperature of intermediate recrystallization annealing used in cold-rolling practice. The non-thermal nature of the fast-flowing initiating processes under irradiation has been shown. It was shown that of fast flowing radiation annealing, which may be qualified as a giant long-range effect under ion irradiation, is comparable with standard furnace annealing.

The effect of Ar+ ion irradiation and subsequent prolonged aging on the microstructure and phase transformations in a B-1461 alloy (Al-Cu-Li-Zn-Mg-Zr-Sc) subjected to megaplastic deformation (MPD) has been studied by transmission electron microscopy. A mixed structure, consisting of nanocrystalline and nanofragmented regions has been found to form in the alloy upon MPD. Subsequent short-term Ar+ ion irradiation (E = 20 keV, j = 300 mu A.cm(-2), F = 1.9x10(15) cm(-2)) forms dislocation tangles, increases the nonuniform distribution and the size of structural elements, as well as volume fraction of a T-2-phase (Al3CuLi5) nano and submicrocrystals heterogeneously nucleated at boundaries. Structural changes are observed at a distance of similar to 200 mu m from the surface, which considerably exceeds the projective ion range (similar to 20 nm). The structure of the B-1461 alloy after MPD and subsequent irradiation under the above conditions is unstable.

The structural and phase transitions in the Al–Li–Cu–Mg–Zr–Sc–Zn alloy subjected to megaplastic torsional deformation under high pressure in the process of low-temperature annealing at 150°C have been studied by electron microscopy. It has been shown that the character of the nanocrystalline structure formed in the annealing process is determined by the specific features of the earlier existing deformation structure and demonstrates structural heredity. The effect produced by the structural state of the annealed alloy on the level of mechanical properties (hardness, plasticity, elasticity modulus, stiffness) is discussed.

The effect of Ar+ ion irradiation on structural and phase transformations in a 1461 alloy (Al-Li-Cu-Mg) subjected to megaplastic deformationhas has been studied by transmission electron microscopy. Short-term irradiation (E = 10 keV, F = 2 x 10(16) cm(-2)) has been established to form a low-energy recrystallized submicrocrystalline structure at a depth (similar to 200 mu m), significantly exceeding the projective ion ranges (similar to 10 nm). The study confirms the important role of the radiation-dynamic effect during the ion irradiation of metastable media. The structural and phase transformations take place in the alloy at a depth of much higher than the projective ion ranges and at a higher rate compared with traditional thermal annealing.

The effect of 10-keV Ar+ ion irradiation on the mechanical properties and structural and phase state of hot-pressed thin profiles 1.5 mm thick and made of an V95 alloy (Al-Zn-Mg-Cu system) after artificial aging (T = 140 degrees C, 16 h) has been studied. Ion beam treatment of the alloy (j = 300 mu A center dot cm(-2), F = 1.9.10(15) and 1.1.10(16) cm(-2)) without heating the samples to significant temperatures (T < 35-50 degrees C) has not been established to change the ultimate strength and yield strength; however, it increases the relative elongation by 1-2 %. Transmission electron microscopy has shown that irradiation changes the grain structure and the morphology of particles of the crystallization origin in the entire volume of quenched and artificially aged V95 alloy samples (1.5 mm thick). The irradiation does not affect the size and the volume fraction of fine strengthening eta'- and eta-phase particles.

Structural and phase transformations in a commercial multicomponent aluminum–lithium alloy have been studied electron-microscopically upon storage after mega-plastic deformation by high-pressure torsion. It has been shown that the arising deformation structure of the alloy is unstable, and upon subsequent storage at room temperature it is transformed via a complex reaction of in situ recrystallization and decomposition of the supersaturated solid solution. The character of the transformation is determined by the regime of the previous mega-plastic deformation and by the duration of the storage.

This paper presents the results of a study of structural transformations and the main tribological properties (coefficient of friction and wear rate) of Al–2.2 Li and Аl–3.1 Сu–2.0 Li–0.1 Zr (wt %) alloys. Optical metallography and transmission electron microscopy have been used to examine the alloy structure after heating and friction. Tribological tests of the alloys in pair with steel are carried out by sliding friction using a pin-on-plate scheme during reciprocating motion of a sample. The sliding velocity is 0.07 m/s and the load is 294 N. Friction is carried out in air and in a nitrogen gas at room temperature. Alloying of the Al–Li alloy with copper (3.1 wt %) and zirconium (0.1 wt %) is shown to significantly increase the wear resistance, enhance the frictional hardening, and reduce the friction coefficient of the alloys. The positive effect of this alloying on the tribological properties of the Al–Li alloy is caused by friction-induced severe strain hardening. A high-strength nanocrystalline structure consisting of a mixture of matrix crystals and a metastable δ' (Al3Li) phase is formed in a surface layer to 10 μm thick. Planar dislocation slip is observed in both alloys. This sliding mechanism is assumed to be related to the low (f ~ 0.25) coefficient of friction of both alloys. Artificial aging carried out under different four regimes increases the hardness of alloys, but significantly reduces their resistance to wear. This paper offers an explanation for the effects obtained.

The structural and phase transformations in the Al–Li–Cu–Mg–Zr–Sc–Zn alloy have been studied by the electron microscopy after the aging for the maximum strength and in the nanostructured state after severe plastic deformation by high-pressure torsion. It has been shown that severe plastic deformation leads to the formation of a nanostructured state in the alloy, the nature of which is determined by the magnitude of deformation and the degree of completeness of the dynamic recrystallization. It has been established that deformation also causes a change in the phase composition of the alloy. The influence of the structural components of the severely deformed alloy on the level of mechanical properties, such as the hardness, plasticity, elastic modulus, and stiffness has been discussed.

The processes of radiation-dynamic nature (in contrast to the thermally-activated processes) in the course of short-term irradiation of 1 mm thick bands of cold-worked aluminum alloy 1441 (of system Al-Li-Cu-Mg) with Ar+ 20-40 keV were studied. An effect of in-the-bulk (throughout the whole of metal bands thickness) low-temperature radiation annealing of the named alloy, multiply accelerated as compared with common thermal annealing processes was registered (with projected ranges of ions of considered energies definitely not exceeding 0.1 mu m). The processes of recrystallization and intermetallic structure changes (occurring within a few seconds of Ar+ irradiation) have the common features as well as the differences in comparison with the results of two hour standard thermal annealing.

To confirm the hypothesis on the shock-wave nature of long-range effects upon corpuscular irradiation of condensed media presumably caused by emission and propagation of post-cascade shock waves, comparative experiments on ion beam modification and mechanical shock-wave loading of specimens of VD1 and D16 alloys of the Al–Cu–Mg system are performed. Direct analogy between the processes of microstructural change of cold-deformed VD1 and D16 alloys under mechanical shock loading and irradiation by beams of accelerated Ar+ ions (E = 20–40 keV) with low fluences (1015–1016 cm–2) is established. This demonstrates the important role of the dynamic long-range effects that have not yet been considered in classical radiation physics of solids.

The structural and phase transformations have been studied in aging commercial aluminum-lithium alloy Al-1.2 Li-3.2 Cu-0.09 Zr-0.11 Sc-0.4 Ag-0.3 Mg in the as-delivered state and after severe plastic deformation by torsion for 1, 5 and 10 revolutions under a high pressure of 4 GPa. Deformation-induced nanofragmentation and dynamic recrystallization have been found to occur in the alloy. The degree of recrystallization increases with deformation. Nanofragmentation and recrystallization processes are accompanied by the deformation-induced decomposition of solid solution and changes in both the nucleation mechanism of precipitation and the phase composition of the alloy. The influence of a nanostructured nanophase state of the alloy on its mechanical properties (microhardness, plasticity, elastic modulus, and stiffness) is discussed.

Structural and phase transformations in commercial aging aluminum–lithium Al–1.2 Li–3.2 Cu–0.09 Zr–0.11 Sc–0.4 Ag–0.3 Mg alloy have been studied after severe plastic deformation by high-pressure torsion (at a pressure of 4 GPa with 1, 5, and 10 revolutions of the anvil) and natural aging (roomtemperature storage) for 1 week and 2 years. It has been found that, in this case, the process of static recrystallization is achieved in the alloy, the degree of which increases with an increasing degree of deformation and time of storage.