Volume 8, Issue 1, February 2018

A method for the construction of initial atomic models of nanocrystals with extrinsic dislocations in grain boundaries for molecular dynamics simulations is developed. The method is used to determine atomic structures and energies of grain boundaries in columnar f.c.c. nanocrystals with [112] column axis.

The influence of excess free volume in the triple junctions of grain boundaries on their mobility is studied by the molecular dynamics method

Oscillations of kinetic temperature in harmonic triangular lattice with random initial velocities.

Monte Carlo results of Curie temperatures (TC) and estimated temperatures of the martensitic phase transition (Tm) for Ni2-xPtxMnGa (0 ≤ x ≤ 1,75) alloys as functions of Pt concentration (x)

By numerical modeling the simple approximate dependence of zinc’s damage f(t) from time t and the initial damage f0 under treatment of pulse high-energy electromagnetic field are obtained (С= 1,228*102 s–1, t0= 9,63 μs, are the proportionality coefficient and the threshold time respectively).

In this paper, we present a method for processing an acoustic emission signal using a discrete wavelet transform. The figure shows an example of an acoustic emission signal and strain hardening curve obtained from an aluminum alloy under tensile loading.

Method of CCT diagram plotting based on the numerical analysis of dilatometric tests results. Dependence of the CTE of austenite and its decomposition products from the range of cooling rates clearly defines critical cooling rate and phase transformation ranges.

The microstructure and local mechanical properties of zones of 12Cr18Ni10Ti steel and a titanium alloy VT1-0 with an intermediate copper insert joint were carried out. The stress–strain diagrams for zones of the joint are received using the original technique for determining coefficients of the “stress–strain” diagram.

Field neon image atomic clean and atomic smooth the surface of platinum single crystal before irradiation, with the corresponding stereographic projection. By irradiation of the single crystal Pt beams of charged Ar+ ions are able to obtain nano-structured state of the material under certain modes in the near-surface volume of the nano meter range.

Metallographic methods were used to study the viscous character of the deformation in the regions of strong localized flow, including Roaldite (Fe, Ni) 4N plates in the alpha (Fi, Ni) meteorite of the Sikhote-Alin meteorite.

Review of actuality research on effect of high constant magnetic field on phase and structural transformations are presented. Figure show fragment of phase diagram Fe-C under magnetic field 10 or 18 T.

In electro-technical textured tape, the formation of optimum narrow zones of plastic deformation across the texture axis decrease the size of magnetic domains 3-4 times. This leads to decrease the speed of motion of the domain boundaries and to considerable reduces by 25% of magnetic losses during magnetization reversal of the material.

Hydrogenation leads to the formation of a gradient state in the steel Fe-17Cr-10Mn-7Ni-1V-0.09С-0.65N (wt.%): thin (<15 μm) brittle surface layer is formed on the side surfaces of the samples, which cracks during plastic flow; the central parts of the samples are destroyed in transgranular viscous mode similar to the samples destroyed without hydrogen charging. The thickness of the brittle surface layer increases and the character of the destruction changes with increasing duration of saturation of the samples with hydrogen in tension: from brittle mixed (transgranular and intergranular) after saturation for 8 and 16 hours to fully intergranular for 32-50 hours of hydrogen-charging.

The transfer of applied mechanical stress from polymer matrix to nanofiller and? Hence, a properties of nanocomposites polymer/carbon nanotubes are defined by structure of aggregates (ring-like formations) of nanofiller, treated within the frameworks of fractal analysis.

The comparative research of wear resistance, hardness and elastic modulus of exemplars from titanic BT6 alloy with the mineral coating created when using the low-temperature technological operations and without coating is conducted. Considering features of measurement of physico-mechanical properties of thin modified layers, measurement of wear resistance was executed by method of a multi-cycle sliding friction by the sapphire sphere with monitoring of force of a clip and deepening of a tip in an exemplar. Creation of a mineral layer increased hardness of a surface of an exemplar from titanic alloy by 45-70%. The wear resistance of the surface of an exemplar modified by minerals increased by 4-5 times in comparison with wear resistance of a surface of titanic BT6 alloy without modification.

A fracture locus for the 10 vol.% V95/SiC metal matrix composite.

At step of deformation from e = 0.5 to e = 4.6, the stage of nucleation of the ω phase is observed only in area of the α-phase, which have a favorable crystallographic orientation. The formation of groups of planar defects in the ω phase is a mechanism for the compensation of elastic stresses during lattice transformation α → ω under conditions of high quasihydrostatic pressure. The figure shows the dark-field image in the reflex (001)ω of the deformed structure at angle of anvil of Bridgman φ=15 grad (e=1.5) of pseudo-single crystal of zirconium

The recrystallization mechanism after ECP was deduced to be similar to that operating during conventional static annealing. The microstructural changes were explained in terms of Joule heating and similar observations for static recrystallization.

TEM of Inconel 718 produced by SLM

Fig 1. The enthalpy release rate under linear heating TP – quenched samples with supersaturated solid solution 0 – sample in the initial state before ECAP 2 – sample after 2 ECAP pass Fig. 2. Particles' size distribution on the mesoscale (SEM) in the initial state and after 8 passes of ECAP Table 1. Changes in the distribution density of particles depending versus their sizes on different stages of processing (TEM)