Obtaining of Copper- and Nickel-Based Polymetallic Gradient Products by Wire-Feed Electron Beam Additive Manufacturing

The structure and mechanical properties of gradient transition zones of the copper-nickel system formed by additive electron beam technology have been investigated. Pure copper and nickel alloy Ni80Cr20 were used for printing. The data obtained testify to the complex and heterogeneous nature of structure formation when printing both by single-wire method and using double-wire controlled feeding of material into the melt bath. In the samples, the formation of defects of different scale from local inhomogeneities of the structure to pores and cracks is possible. The mechanical properties of the structural gradient zone are at a sufficiently high level and depend on the ratio of the system components.

Hardness and Microstructure Homogeneity of Pure Copper and Iron-Chromium Alloy Processed by Severe Plastic Deformation

Hardness and microstructure homogeneity of pure copper and iron-chromium alloy processed by severe plastic deformation (SPD) were investigated in grain refinement. Equal channel angular pressing (ECAP) is one of the well-known techniques of the SPD technique due to their up-scale ability and other methods. SPD was applied to pure copper and iron-chromium alloy at comparable temperatures up to four passes. The microstructure and microhardness were observed and measured in the transverse plane for each billet. The homogeneity observation was carried out from the sub-surface until in the middle of the billet. The result showed that the deformed structure appeared adequately after the first pass and had a higher hardness level. The first pass showed a higher inhomogeneity factor than the fourth pass due to the homogeneity microstructure. The hardness also showed homogeneous value along the transverse plane, and it was concluded that ECAP could achieve complete homogeneity in grain refinement

Высокотемпературная сверхпроводниковая магнитная система для изучения нейронной активности

The paper describes a high-temperature superconducting magnetic system (HTS SMS) to equip an experimental stand intended for neuron activity researches under constant and low-frequency magnetic fields up to 1 T. The design of the magnetic system together with its electromagnetic and cryogenic parameters is briefly discussed. The test results of the preliminary experiments conducted in liquid nitrogen at 77 K for two interchangeable magnets are given. The first magnet was manufactured in the form of a double pancake coil wound with 4 mm high HTS tape. The second magnet was made of pure copper wire with no frame and was impregnated with a thermally conducting epoxy resin. The advantages of the HTS pancake coil were demonstrated in comparison with the cryo-resistive solenoid. Low energy consumption of the HTS magnetic system will allow conducting continuous non-invasive monitoring of biological objects in a magnetic field.

Investigation of Wear Properties of Microtitanium and CNT Particulates Reinforced Copper Hybrid Metal Matrix Composite

Current engineering applications require materials that are stronger, lighter, and less expensive. Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and strength of composite materials. In the recent days, there is a huge demand for a lightweight material such as composites seems to be a promising solution to this arising demand. These materials have gained attention due to their applications in the field of automotive, aerospace, sports goods, medicines, and household appliances. This study represents the work done by various researchers and their methodologies. In contrast with most metallic materials, copper alloy has many remarkable properties, such as its excellent electrical and thermal conductivities, good strength, and formability, having outstanding resistance to corrosion and fatigue, and others. Due to their excellent properties, copper alloy is widely used in electrical, automotive, architecture, petrochemicals, transportation, and marine industry. In this work the different percentages of CNT and MicroTitanium are reinforced with pure Copper and are studied. The current work investigated the influence of the CNT and MicroTitanium on the wear behavior (tribological behavior) of developed hybrid metal matrix composite. The conventional liquid stir casting technique will be used for the fabrication of the composite materials. The composite was produced considering combination of0.5, 1, 1.5 percentages of CNT and 1, 3, 5 percentages of Micro-Titanium. The specimens were prepared as per ASTM standard size by turning and facing operations to conduct wear test. The specimens for investigation of wear were tested using pin on disk apparatus. Through the results, it is concluded that the hybrid MMC obtained has got better reduction in wear rate. The inclusion of CNT has played a major role in reducing the wear rate and addition of micro titanium has decreased the wear rate to some extent Keywords: Wear, Copper, Micro titanium, CNT, MMC