The paper presents a metallographic study of aluminum alloy welds produced by friction stir welding. The weld structure is described for two alloys: Al-Cu and Al-Mg. It is shown that friction stir welding provides a fine-grained structure of the weld. The phase composition of the weld metal for the studied alloys is defined. Differences in the structure and distribution of second-phase particles in the weld metal are shown. The weld zone of Al-Cu alloy consists of equal size grains, with intermetallic particles located along the grain boundaries. The weld structure of Al-Mg alloy is banded, with alternating layers consisting of different size grains.

A molecular-dynamic simulation of the behavior of unclosed nanostructures obtained by self-scrolling of nanosized bilayer Ni–Сu films with different internal structure compositions is performed. In the course of selfscrolling of a nanosized film in the absence of any external action, its edges undergo weak decaying harmonic oscillations. Peculiar effects of the initial film internal structure on the oscillation characteristics are found out. It is shown that by varying the initial film composition or saturating it with structure defects, one can deliberately change the oscillation amplitude or frequency, or both of them simultaneously. The layer composition is changed in such a manner that the geometrical dimensions of the simulated nanostructure remain practically unchanged. The observed peculiarities are appealing for research and development of accessories and hardware for nanodevices of different types and applications.

The behavior of nanodimensional bilayer structures (plates) of finite length consisting of nanometer-thick crystalline Ni and Cu films has been studied by means of molecular dynamics simulation. The inter-atomic interactions were described within the framework of the embedded atom method. It is shown that, in the absence of an external action, the nanostructures perform mechanical oscillations with the amplitude and frequency determined by the length and thickness of the plate. The dependence of the parameters of oscillations of the nanodimensional structures on their dimensions is established. The results can be used in designing components of nanodevices for various applications.

Behavior of unclosed nanostructures is investigated in the course of their formation from bilayer films of a Ni–Cu system with crystal structure. The investigation is performed on the basis of the molecular dynamics method using a many-body potential of interatomic interaction. It is shown that the edges of an unclosed nanostructure produced from a bilayer metal film can perform free harmonic oscillations. The dependence of the oscillation amplitude of the nanostructure on the size of the initial film is investigated. Optimum geometrical parameters of the initial film are determined in order to form unclosed nanostructures oscillating with maximum amplitude. The results obtained are promising for the development of components for nanodevices of different types and applications.

The behavior of open nanostructures formed on the basis of double-coating films of Ni and Cu has been examined within the bounds of molecular dynamics method. Interatomic interaction was described within the bounds of the method of embeded atom. The dependence of vibration amplitude on original film sizes was studied and geometrics at which nanostructure oscillates with maximum possible amplitude were determined. The obtained results are of interest for development of components of nanodevices of different functions.

An important problem during automatic calculation of nesting plans is the selection of parts orientations. The widely used selection of orientation from the specified list can result in decreased nesting quality. A clusterization algorithm is suggested, which uses the analysis of local geometrical characteristics of details for orientation selection

The molecular dynamic method was applied to inquire into the behavior of a loaded-off composite material in the region containing undeformable inclusions. Calculations showed waves of atomic displacements to occur and propagate along the interfaces with incompatible strains. It was revealed that in a loaded-off material relaxation processes brought about the formation of a block structure where the angles of block misorientation could be as high as tens of degrees.

Molecular dynamics techniques are used to show that heat can be transferred ballistically in threedimensional crystalline materials at temperatures on the order of Debye temperatures.

Generation of nonlinear solitary waves in a system described by many-body interatomic interaction potentials is modeled for the first time. The behavior of a free surface of Ni and Al crystallites under high-rate loading is studied. Calculations show that solitary pulses produced by high-rate loading increase in amplitude by about a factor of 1.5 at the free surface of Ni and remain almost unchanged at the free surface of Al. The nature of this effect is associated with differences in the skeleton-skeleton interaction of Ni and Al.

The nonlinear response of a material under a high-energy process acting on groups of atoms or individual atoms of a free surface is studied. The dissipation of the energy transferred by soliton-like pulses at structural defects, such as regions with high vacancy density, grain boundaries, and the free surface, is investigated. A method of describing the “longrange action” during ion implantation in metallic materials is proposed.

Hugoniot adiabats and isoentropic unloading curves for Ni and Al and their ordered NiAl and Ni3Al alloys are calculated within the framework of a method based on the electron-density functional theory. The residual temperature and volume of a completely unloaded material are determined under various initial states on the Hugoniot adiabat. The results of calculation of the adiabats for pure metals are in conflict with known experimental data by no more than 15%. It is s shown that the thermodynamic parameters which characterize the alloys considered under the conditions of a shock-wave experiment are close to the corresponding values for pure Ni and are not the lumped averages of the corresponding characteristics of pure metals.