Research results of manufacturing composite filamentary nanostructure Cu-Ag alloys with silver addition from 5 to 15% wt. are presented in the paper. Manufacturing technology of these composites and variable solubility of silver in copper and copper in silver in the range of solid solutions. Suitable quantity and processing sequences of high deformation plastic working and heat treatment allows to obtain wires constituted from Cu and Ag fibres with nanometric transverse dimensions and in consequence provide to optimum superposition of high mechanical strength, high electrical conductivity and sufficient ductility of Cu-Ag alloys. The paper presents the method of continuous casting of alloys, selected physico-chemical properties and degree of deformation. Influence of chosen heat treatment method over electrical and mechanical properties of both casts and micro wires on mechanical and electrical properties of cast materials during converting them into micro wires with tensile strength higher than 1200 MPa and electrical conductivity higher than 40 MS/m are presented too. Research results of optical and scanning microscopy structure analysis were presented for casts and wires submitted to various thermo-mechanical strengthening.
The raw material for the production of Al-Mg-Si wires is wire rods, created in the Continuus Properzi line in temper T1 (cooled after forming at an elevated temperature and after natural aging). The general technologies for shaping the mechanical and electrical properties of Al-Mg-Si wire rods include two kinds: high- and low-temperature heat treatments. High-temperature heat treatment includes a homogenization process and a supersaturation process. Low-temperature heat treatment takes place after supersaturation and includes natural or artificial aging. This study shows how the amount of Mg and Si influences the mechanical and electrical properties of EN-AW 6101 wire rods after different kinds of heat treatments. As the general aim of this study was to determine the effect of the material’s temper on its mechanical and electrical properties, the research considered the initial parameters of the starting materials being examined. These parameters can be modified by selecting the chemical composition of the Al-Mg-Si alloy and the value of precipitation hardening obtained with artificial.
14 March 2014 in Metallurgical and Materials Transactions B
Currently, there is a worldwide search for new forms of materials with properties that are significantly improved in comparison to materials currently in use. One promising research direction lies in the synthesis of metals containing modern carbon materials (e.g., graphene, nanotubes). In this article, the research results of metallurgical synthesis of a mixture of copper and two different kinds of carbon (activated carbon and multiwall carbon nanotubes) are shown. Samples of copper–carbon nanocomposite were synthesized by simultaneously exposing molten copper to an electrical current while vigorously stirring and adding carbon while under an inert gas atmosphere. The article contains research results of density, hardness, electrical conductivity, structure (TEM), and carbon decomposition (SIMS method) for the obtained materials.
Eight hypoeutectic aluminium alloys with iron content within the range of 0.07-1.09% by weight, were examined. The structure, the mechanical and electrical properties of wires used for electrical purposes were studied. The batch material for the drawing process was wire rod obtained from the continuous casting and rolling line by Continuus-Properzi method. It has shown a linear relationship between mechanical properties of wire rod, a higher plasticity of wire after drawing process and an increase in thermal resistance of the material with increasing iron content. The findings enable to draw conclusions of basic and application characteristics, pointing to the possibility of using aluminium with higher iron content in the wire drawing process of small diameter and microwires for the production of automotive bundles, accumulator cables and winding wires.
Intensive research is underway worldwide to develop new conductive materials for applications in the power industry. Such tests aim to increase the electrical conductivity of materials for conductors and cables, thus increasing the current carrying capacity of the line and reducing the loss of electricity transmission. The scientific discovery of recent years, graphene, one of the allotropic types of carbon with very high electrical and thermal conductivity and mechanical strength, creates great opportunities for designing and producing new materials with above-standard operational properties. This project concentrates on developing technology for manufacturing aluminum-graphene and copper-graphene composites intended to be used to produce a new generation of power engineering conductors. In particular, we present the results of the research on the mechanical synthesis of aluminum-graphene and copper -graphene composites, as well as the results of the electric, mechanical, and structural properties of rods obtained after the extrusion process and wires after the drawing process.