S. L. Demakov

Effect of annealing temperature on the texture of copper wire

It has been found by textural analysis methods that, in the course of annealing with heating and cooling at a rate of 100 K/s, the textured state of an oxygen-containing copper wire of grade M00 deformed by drawing to 97% reduction changes, retaining the zonal structure. In the central zone, at a relative current radius from 0 to 0.3, the 〈111〉 orientation dominates to a temperature of 300°C. At the higher temperatures, the 〈100〉 orientation becomes dominant and remains up to 500°C. At relative current radii of 0.6–1.0 (peripheral zone) and 0.3–0.6 (intermediate zone), the dominant 〈100〉 orientation is retained to 300°C; at the higher temperatures, the dominance of the 〈100〉 orientation levels off. As the annealing temperature increases, the intermediate zone wedges out at the expense of growth of the central and peripheral zones. On the whole, the annealing at high temperatures (above 400°C) leads to the predominance of the 〈100〉 orientation; it is highly dominant for relative radii of 0–0.5.

Structural and phase transformations in a quenched two-phase titanium alloy upon cold deformation and subsequent annealing

Methods of X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and differential scanning calorimetry have been used to study the formation of the structure and phase composition upon the cold rolling of rodlike semi-finished products of the VT16 alloy quenched for martensite (Tq = Tpt − 10 K). It has been established that, with an increasing degree of elongation caused by rolling in the range under investigation, a more complete deformation-induced transformation occurs according to the scheme α″ → (α′ + βa) with the formation of a βa solid solution with an anomalously large lattice parameter because of the development of accommodation processes due to the difference in the specific volumes of the initial (α″) and arising (α′) martensitic phases. A correlation between the phase composition and the microhardness and elastic characteristics has been established. The temperature intervals of the occurrence of the processes of solid-solution decomposition have been determined upon the continuous heating in the quenched and cold-rolled states.

Interaction of a copper oxide particle with copper in drawing

The forming of copper near a copper oxide particle is determined during multiple-pass drawing. The interaction of the copper oxide particle with copper is studied by the calculation of the state of stress in a finite element formulation and using scanning electron microscopy data. The results obtained demonstrate that pores appear around copper oxide particles when strain accumulates in multiple-pass drawing machines. The pore length increases with the accumulated strain, which can result in breaks of a wire in a highly cold-worked state.

Phase diagram of the Co–Al–W system. structure and phase transformations near the Co3(Al, W) intermetallic composition range

Low-temperature portion of the polythermal section for the Co–Al–W system in the vicinity of the Co3(Al, W) intermetallic composition has been studied experimentally using electron microscopy and hightemperature X-ray diffraction analysis. Low-temperature structural phase transformations and temperature ranges of the existence of phases have been determined. The morphology of Co3(Al, W) intermetallic particles was studied as a function of the tungsten content in alloys.

Study of magnetic properties and structural and phase transformations in the Co-19 at % Al-6 at % W alloy

The Co-19 at % Al-6 at % W alloy prepared by two methods of melting in an inert atmosphere, namely, by arc melting followed by casting into a water cold copper mold and induction melting followed by casting in a ceramic (Al2O3) mold, has been studied. It was found that the phase composition of the alloy and its magnetic properties depend on the cooling rate of ingot after melting. Samples are ferromagnetic up to 800°C; the specific magnetization equal to σ= 10 emu/g is retained up to ∼700°C. The Curie temperatures of all phases found in the alloy have been determined. It was found that the formation of the Co7W6 phase in the alloy increases the coercive force of the alloy, whereas the saturation magnetization demonstrates a 1.5-fold decrease.

Assessing the Consequences of the Softening of Metal During Hot-Working by Using the Software Package QForm V8

This article examines the effect of the strain-hardening parameters of a deformable material on the strain distribution in a product obtained by upsetting. The study was conducted with the use of materials having different types of strain-hardening curves. Results obtained by modeling and an experiment show the uniformity of the strain distribution.

Severe deformation, structure, and texture of the metal in the production of capillary copper tubes

The structure formation in the production of capillary copper tubes is studied using the computational methods of deformable medium mechanics and structural and texture analyses. It is found that intense deformation develops in the real process at a percent reduction up to 99.998%, and the strain tensor components are shown to be nonuniformly distributed. The predominance of the tangential component of the strain tensor leads to the formation of grains with long axes located along the longitudinal and radial coordinate axes near the inner surface of a capillary tube. Texture analysis supports these conclusions.

Study of the martensitic transformation in the Co–9 at % Al alloy

Phase transformations in the Co–9 at % Al have been investigated after slow furnace cooling. It has been shown that the structure and phase composition of the alloy after slow cooling do not correspond to the equilibrium phase diagram of the alloy of this chemical composition. It has been established that the α → ε martensitic transformation does not require overcooling and occurs even during a slow cooling of the alloy. It has been found that the formation of 4H modulated martensite is a specific feature of the binary alloys of cobalt and is not connected with the rate of their cooling. The Curie temperatures for the B2, α, and ε phases have been determined.

Effect of annealing on properties of hot-rolled electrical copper

Experiments on the annealing of hot-rolled oxygen-containing copper in the temperature range of 300–700°C have been performed and the properties and the structure of the metal after this treatment have been investigated. The mechanical properties were studied by constructing tensile stress-strain curves and by determining the ultimate tensile strength, offset yield stress, percentage elongation, reduction of the area, hardness, and modulus of elasticity. The structural studies were performed using optical and electron microscopy. It has been established that the most substantial decrease after annealing at temperatures above 500°C is characteristic of the offset stress (by 62% for copper annealed at 600°C). The spheroidization of pores around the particles of copper oxides at the annealing temperature of 600°C has been revealed. It has been established that the annealing of the hot-rolled copper at temperatures of 500–600°C leads to an increase in the plastic properties of the metal due to the development of the mechanism of the spheroidization of pores and a decrease in the effect of stress concentrators.

Fiber vs Rolling Texture: Stress State Dependence for Cold-Drawn Wire

Abstract The texture of the cold-drawn copper wire was investigated along the radius using electron backscatter diffraction. The complex fiber texture of the central region of the wire was considered as the rolling texture consisting of a set of preferred orientations. The texture of the periphery region was revealed to be similar to the shear texture. The orientation-dependent properties of the wire were proven to be determined by the texture of the near-surface layers.