230 research outputs found
Regularities and mechanisms of formation of submicro-, nano-, and ultrafine-grained structures and mechanical properties of metals and alloys under different treatments
Within the recent two decades, ultrafine-grained (UFG) (grain size 1-10 μm), submicrocrystalline (SMC) (grain size on the order of or less than 0.1-1 μm), and nanostructured (NS) (grain size on the order of or less than 0.1 μm) metals and alloys produced by large (mature) [1-4], severe plastic (SPD) [5], and megaplastic deformation (MPD) [6] have been intensively investigated and ever increasingly used in medical and engineering applications. In all these cases the process of deformation takes place under high applied pressures and degrees of the resulting plastic deformatio
Study of the evolution of the Cu/Nb interphase boundary by the molecular dynamics method
The evolution of atomic structure of the interphase boundary for composites from immiscible Cu/Nb elements is studied by the molecular dynamics method. It is established that the planar interphase boundary is stable at temperatures up to 1200 K. Atomic dissolution of elements is not revealed in the entire examined temperature interval, and the components are mixed on the interphase boundary of finite curvature in the form of clusters and nanolamellas; moreover, the amorphous state is not formed in the process of migration of the interphase boundaryyesBelgorod State Universit
Studying grain-boundary stresses in copper by the molecular-statics method
Grain-boundary stresses in copper for 60 symmetrical tilt grain boundaries with different orientations of the grain-boundary plane and tilt axis have been calculated by the molecular-statics method with the use of embedded-atom-method potentials of interatomic interactionyesBelgorod State Universit
Self-diffusion parameters of grain boundaries and triple junctions in nanocrystalline materials
Suggested methods describe the process of self-diffusion along grain boundaries and triple junctions in polycrystals without using geometric models of the grain boundaries structure. The calculation method introduced diffusion characteristics along grain boundaries derived from the results of molecular dynamic simulations of nanocrystalline materialsyesBelgorod State Universit
Near-threshold femtosecond laser fabrication of one-dimensional subwavelength nanogratings on a graphite surface
Superimposed one-dimensional quasiperiodic gratings with multiple periods Λ≈110–800 nm well below or comparable to the pump laser wavelength of 744 nm, and ridge orientations perpendicular to the linear polarization of infrared femtosecond laser pulses, were fabricated after multiple near-threshold laser shots on a planar surface of quasimonocrystalline graphite in ambient airyesBelgorod State Universit
Influence of implants surface properties on bone tissue formation in the ectopic osteogenesis test
We studied the influence of the characteristics of oxide porous coatings on osteogenesis and integration of new bone tissue and titanium implant surface in the ectopic osteogenesis test. Implants with coating with pore size 2-20 μ exhibit better osteogenic and osteoconductive characteristics than implants with homogenous surface and smooth relief (pore size 0.5- 5.0 μ). Physical characteristics of the surface of the material along with chemical composition of the coating are essential for the formation of bone tissue and its integration with the implan
Transformations in the grain boundary ensemble of M1 copper subjected to equal-channel angular pressing during recrystallization annealing
The grain structure of M1 copper subjected to equal-channel angular pressing (ECAP) and subsequent annealing at 593K for 1 h is studied by means of transmission electron microscopy and scanning electron microscopy with the diffraction of backscattered electron
Investigation of the structural-phase state and its role in the formation of heat-resistance properties of 12% chromium steel
Results of investigations into the structural-phase state of EK-181 ferritic-martensitic low-activate steel after thermal treatment including quenching, intermediate tempering, and subsequent long tempering under loading at temperatures of 923 and 973 K are presentedye
Sub-100 nanometer transverse gratings written by femtosecond laser pulses on a titanium surface
One-dimensional transverse (perpendicular to the laser polarization) gratings with periods Λ ≈ 50-60 nm were observed on a titanium surface within 150 nm wide, micrometer-long regular surface modification longitudinal stripes fabricated by multiple 744 nm Ti:sapphire femtosecond laser shots, occurring at a repetition rate of 10 HzyesBelgorod State Universit
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