L. A. Teplyakova

Distribution of slip tracks in single crystals of Ni3Fe alloy

The results of an experimental investigation of the distribution of slip tracks in a primary system in single crystals of Ni3Fe alloy, oriented for a single slip, are presented. Investigations were carried out over a range of scales which differed by three orders of magnitude. Histograms of the distances between slip tracks at different scale levels are constructed. Self-similar track distributions in the primary slip system over the range of scales investigated are established.

Band structure and packet-martensite structure. Comparison of evolution paths

We consider the similarities and differences between the band substructure and the packet-martensite structure in Ni3Fe alloyed with 38KhN3MFA steel. The variation of their quantitative characteristics with strain and with initial polycrystal grain size is analyzed. The main factors governing the morphological features and the behavior of the considered structures are found to be the laws governing the evolution of the dislocation-disclination ensemble.

Evolution of the dislocation structure and the stage of work-hardening of Ni3Fe alloy with [001] orientation

Using transmission diffraction electron microscopy, the dislocation structure of work-hardened iron nickel alloy with the compression axis in [001] orientation is studied over a wide interval of gradual strain. A connection is established between the change of the flow curve and the type of substructure formed. The quantitative characteristics of the observed structural types are determined and their behavior at different stages of the strain curve is traced.

Transformations of Dislocation Substructures under Fatigue Loading

Research literature on dislocation substructures formed in fcc metals and alloys under fatigue loading is reviewed. The materials are classified into three groups according to the types of dislocation substructures formed at the onset of fatigue loading and transformation sequences occurring on further loading. Quantitative results obtained from investigations of the evolution pattern of the defect subsystem formed under fatigue loading are examined.

Influence of the Substructure Type on the Carbon Redistribution in Martensitic Steel in the Course of Plastic Deformation

The phase and structure transformation of tempered martensitic steel in the course of plastic deformation is considered in the present paper. A close correlation between the evolution of the substructure type and the behavior of carbon is established. The carbon concentrations in solid solution and on crystalline defects of the material as a whole and in different dislocation substructures are investigated versus the degree of plastic strain.

The effects of test temperature on the work-hardening characteristics of Ni3Fe ordering single crystals oriented for multiple slip

Results are reported on the temperature dependence of work-hardening characteristic of Ni3Fe single crystals in the ordered and disordered states; there is a slight anomaly in the temperature dependence of the yield stress in stage II in both states, and the same applies to the relative hardening factor ΘΠ/G.

Direct crystal plasticity model: Application to the investigation of single crystal fragmentation under uniaxial loading

The mathematical formulation and the results of solving a boundary value problem of uniaxial loading of single-crystal aluminum samples are reported. A first-type direct model was used for the solution of the boundary value problem. The material response is determined within the crystal elastoviscoplasticity theory. The fragmentation of the initially homogeneous sample into zones with different internal structure evolution is shown.

Deformation-induced destruction of the long-range order in single crystals of Ni3Fe alloy

In the present work, x-ray diffraction and electron microscopy are used to investigate the state of a Ni3Fe single crystal during plastic deformation. It is demonstrated that the observed destruction of long-range atomic order is accompanied with splitting of superdislocations and generation of single dislocations. The change of the long-range order parameter for single crystals deformed in the [001] direction estimated from the degree of splitting of superdislocations is in good agreement with x-ray measurements of this parameter. The destruction of long-range order for intermediate deformations ε < 40% is well described by the model of mechanical mixing of the alloy, the main role in which is played by the mechanisms of plane defect generation by shears along slip planes.

Anomalous mass transfer and phase and structural changes in ?-Fe when acted upon with electron pulses

The phase composition and the defect structure of armco-iron irradiated with a relativistic electron beam is investigated using electron microscopy and x-ray structural analysis. Specimens with a chromium coating and without it were irradiated.

Laws of substructural and phase transformations in the plastic deformation of martensitic steel

Substructural and phase transformations in the course of plastic deformation in tempered 34KhN3MFA steel are considered. A relation is established between the type of substructure and the phase state of carbon. A direct relation is established between the carbon content in the solid solution and the crystal-lattice distortion. The carbon concentration at dislocations and fragment boundaries is determined.