Accumulation of Deformation in the Winding Circuit

The formulas and an approximate analysis of the results of the accumulation of deformations in the operations of winding the wire into a spiral and unwinding it to its original state are given. The results of the experiment on winding a thin silver wire on the mandrel and unwinding it to its initial state are presented. The experiments on stretching the wire took place before and after the loading. It was revealed that under the test conditions the notional yield limit increases abruptly, relative elongation is reduced and tensile strength changes slightly. Comparison of load-extension diagrams before and after testing is given as well.     Keywords: wire, hardening, silver, stretching, winding, deformation, stress, mechanical properties

Finite element modeling of the upsetting of an anisotropic cylindrical workpiece

Anisotropic material deformation is modeled with the application of the finite element method. Hill's yield criterion is used for simplified conditions of the upsetting process. The largest flow stress direction is determined to be parallel to all the three coordinate axes by turns. It is discovered that the base of the cylinder can take an oval shape when the flow stress directions of various values lie in the base plane. In this case, the smaller axis of the oval corresponds to the largest flow stress direction. When the flow stress directions of various values lie in the longitudinal section plane of the workpiece, its shape remains cylindrical. The deformation load is higher in this case. © 2017 Author(s)

The properties of coke breeze briquettes produced by ram briquetting

The paper reports on the results of briquetting coke breeze with a binder in a closed cylindrical press-die. Liquid glass is used as a binder. Approximating curves for the "compaction ratio vs. compaction pressure" dependences are plotted from experimental data. The mechanical properties of the briquettes are determined, namely, drop damage resistance and breaking stress. The results are presented as approximating dependences in the form of a power function. © 2017 Author(s)

Evolution of surface defects in platinum alloy wire under drawing

The shape and chemical composition of particles polluting the surface of ultrafine wire made of the platinum Pt92.5Pd4Rh3.5 alloy has been revealed by electron microscopy and microspectral analysis. The phenomenon of the appearance of pores in the particles, which are elongated in the direction of drawing, has been discovered. The problem of calculating the stress-strain state is stated by the finite element method. After solving the problem, it is demonstrated that the appearance of additional defects is related to the proportion of stresses in the scheme of metal forming by drawing. © 2017 Author(s).The work was done within the State Task, theme No. 01201375904, and financially supported by the RF Government, No. 211 (contract No. 02.A03.21.0006)

Briquette compacting in container with a small taper angle

The aim of the study is to determine the strain state of a briquette during the compacting process. Modeling is performed with the use of a software system for the compaction process. Gurson's yield condition for a plastically compressible continuum is applied. A comparison of the known experimental data is made, and it shows good qualitative convergence results. © 2018 Author(s)

Anisotropy of additively manufactured Ti-6-4 lattice structure

Selective laser melting (SLM) is an additive manufacturing technique, where several aspects resulting in the anisotropy of properties is combined. This study provides an analysis of selective laser melting of the diamond lattice structure of Ti-6Al-4 in terms of anisotropy of Vickers microhardness depending on the location and direction of indentation. A statistical review of microhardness values is presented. © 2019 Author(s)

Flow capacity of the capillary copper tube as its figure of merit

The use of capillary copper tube is popular for manufacturing of gauges and evaporators of refrigeration units. Its main feature is a small inner diameter (no more than 0.9 mm), which makes it difficult to measure it along the whole length of the tube, thus, indirect test methods are used for its determination. Main problem in manufacturing of quality tubes is providing the necessary flow capacity. This article features these under-investigated issues by determining correlation between technological parameters and figures of merit of the capillary copper tubes. Specifically, it was found how flow capacity changes by the influence of such parameters as heat treatment (annealing), tube channel diameter and length of the treated product. © 2020 Published under licence by IOP Publishing Ltd.The work has been performed with financial support of the Government of the Russian Federation, Act No. 211, Contract No. 02.A03.21.0006