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The effect of iron and silicon addition on the structure and properties of aluminium wire rod obtained in the laboratory horizontal direct chill casting process has been analysed. In addition, the impact of laboratory wire drawing process has been examined. The addition of iron and velocity of casting increase the strength of aluminium wire rod in as-cast condition while the electrical conductivity drop acceptable. Moreover, the laboratory wire drawing process causes work-hardening wires and increase drawing tension as a result of fragmentation of structure and growth of grain boundaries. It has been shown that iron is beneficial for mechanical and technological properties of aluminium.

Currently we can observe a worldwide trend to find new materials with extraordinary properties. In particular these researches are aimed to find a method to improve electrical conductivity, mechanical properties, corrosion resistance and rheological behavior of known materials. This effect can be achieved by a synthesis of modern carbon materials with metals. In this paper authors presented research results of synthesis process for Cu-graphene and Cu-CNT’s composites obtained by the mechanical synthesis in cold drawing process. The article presents also the results of electrical conductivity measurements and structural analysis of carbon particles presence in copper matrix. The research has shown that obtained composites have electrical conductivity lower than used copper base material. Additionally, the structural analysis has shown that after the drawing process carbon materials particles are mechanically pressed into Cu in the matrix, and these particles do not participate in the current flow, creating an actual barrier for electrons transport.

The paper examines the influence of axial tension on the linear electrical resistance of single-layer aluminum alloy conductors and showed that when the tension is applied the linear resistance stabilizes at a lower level in comparison to conductors with no tension or with low value of tension. The effect of pressure forces occurring in the interwire contact area was also examined and it was found that the hardness of the material and the range of deformation locally increases as the average pressure at maximum compression force increases. [ABSTRACT FROM AUTHOR]

The present paper is dedicated to the search for an alternative material based on an aluminum (Al)-few-layer graphene (FLG) composite for use in electrical applications. Due to its excellent properties, graphene has the potential for use in many applications, especially in electronics, electrical engineering, aerospace, and the automotive industry. One area where the properties of graphene can be exploited is in overhead power transmission, where the main challenge at the moment is to reduce transmission losses. The utilization of conductors that exhibit superior electrical conductivity is instrumental in ensuring the mitigation of transmission losses. The utilization of graphene or other carbon allotropes is appealing due to their elevated electrical conductivity, substantial mechanical strength, and considerable heat resistance, which can enhance the properties of the composite, thereby increasing its resistance to operational conditions, particularly long-term exposure to temperature, a parameter closely related to the current carrying capacity of the OHL. This article presents the findings of research on the production of a composite based on aluminum powder and graphene, as well as the identification of its electrical and mechanical properties. The primary challenge in this research lies in the development of a method to synthesize carbon materials with aluminum using powder metallurgy, with particular attention paid to the mixing and compacting process, which is of significant importance in ensuring the appropriate distribution of carbon material in the composite. The research carried out has determined the influence of the graphene content (0.1-1 wt.%) on the electrical conductivity (max. 35.4 MS/m) and mechanical properties of Al-FLG composites (UTS = 156 MPa).

Traditional ACSR overhead wires, which consist of a high-strength steel core and several layers of aluminium wires, are currently the most popular overhead line conductor (OHL) design globally. Operating conditions, particularly operating under varying stresses from Karman vortices, lead to the fatigue cracking of wires of the outer layer, followed by wires of the inner layers. Karman vortices are formed by the detachment of a laminar wind stream flowing around the conductor, which causes vibrations in the conductor called wind or aeolian oscillations. Aluminium wires are manufactured using standard batch material drawing technology. Although the fatigue strength of such wires is not standardised, there are various criteria for evaluating this characteristic, as well as established limits on the number of cycles needed to break the first wires of the outer layer. Fatigue strength also strongly depends on the geometric structure of the wire and its operating conditions. The article analyses the influence of the mechanical condition of aluminium wires used in ACSR cables on their fatigue strength. We then present results from aluminium wire fatigue tests conducted on a specially constructed test rig. In addition, fatigue cracks were interpreted using scanning microscopy.

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.

The properties of copper in its solid state are strongly affected by the crystallization conditions of the liquid material. ETP grade copper (Electrolytic Tough Pitch Copper) contains oxygen, which causes Cu 2 O oxide to crystallize in the interdendritic spaces during solidification process which due to the shape of continuous casting mould and the feed of liquid copper during the crystallization process in strand casting might cause a high risk of macrosegregation of oxygen in the copper structure. In the current paper the implied interactions of the dendritic structure of the copper strand in terms of homogeneity at the cross-section of its electrical, mechanical and plastic properties determined based on the samples taken parallelly and perpendicularly to the surface of the dendritic boundaries were analysed. The obtained results were confronted with scanning electron microscopy (SEM) images of the fractures formed during uniaxial tensile test. It has been observed that when the crystallites were arranged perpendicularly to the tensile direction the yield strength (YS) was lower and the fractures were brittle. On the other hand, when the crystallites were arranged parallelly to the tensile direction the fractures were plastic and elongated necking was observed along with the higher YS and total elongation values. The differences in values vary in terms of the applied direction of the tensile force. A characteristic positioning of the Cu 2 O oxide particles inside the fracture depending on the crystallite alignment and the direction of the applied tensile force has been observed.