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.

The research paper presents the impact of the scandium additive and various conditions of the heat treatment on copper mechanical, electrical and heat resistance properties. The performed research works included manufacturing of CuSc0.15 and CuSc0.3 alloys through metallurgical synthesis with the use of induction furnace and following crystallization in graphite crucibles at ambient temperature. Additionally, a CuZr0.15 alloy was produced as a reference material for previously synthesized Cu-Sc alloys. During research, the selection of heat treatment for the produced materials was conducted in order to obtain the highest mechanical-electrical properties ratio. Materials obtained in such a way were next subjected to thermal resistance tests. Parameters of thermal resistance test included temperatures from the range of 200-700 °C and 1 h of annealing time. The research has shown that CuSc0.15 and CuSc0.3 alloys have higher heat resistance after their precipitation hardening compared to the Cu-Zr alloy. The paper also presents microstructural research of the produced materials, which showed that alloying elements precipitates are mainly localized at the grain boundaries of the material structure.

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.Keywords: silver-copper alloys, continuous casting, drawing, micro-wires, filamentary micro-composite, nanostructure, high conductivity, high strength Praca dotyczy badań nad kształtowaniem zespołu bardzo wysokich własności wytrzymałościowych i elektrycznych drutów i mikro-drutów ze stopów CuAg5 i CuAg15. Technologia wytwarzania drutów ze stopów Cu-Ag wykorzystuje zjawisko obustronnej zmiennej rozpuszczalności składników stopów w stanie stałym. Jak wykazały przeprowadzone badania, odpowiednie połączenie przeróbki plastycznej materiałów o strukturze odlewniczej z międzyoperacyjną obróbką cieplną umożliwia uzyskanie korzystnej kompozytowej mikrostruktury silnie wydłużonych włókien Cu i Ag o nanometrycznych wymiarach poprzecznych. Optymalizacja parametrów technologicznych pozwala na uzyskanie drutów i mikro-drutów Cu-Ag o wytrzymałości na rozciąganie w zakresie 1000÷1300 MPa przy równocześnie wysokiej przewodności elektrycznej wynoszącej 70÷85% w skali IACS.W artykule pokazano metodę uzyskania stopów Cu-Ag oraz wyniki badań wybranych własności fizykochemicznych, schemat odkształcenia oraz badania wpływu wstępnej obróbki cieplnej materiałów w stanie odlanym na zmianę własności elektrycznych i mechanicznych zarówno odlewów jak i drutów po przeróbce plastycznej. Zamieszczono także wyniki obserwacji strukturalnych przy zastosowaniu mikroskopii optycznej i skaningowej odlewów oraz ewolucję struktury po przeróbce plastycznej oraz po różnych etapach międzyoperacyjnej obróbki cieplnej.

The modern high voltage power overhead lines operate with high temperature low sag (HTLS) conductors due to possibility of the current capacity increase. HTLS conductors are material and technological advanced solutions. The main advantage of HTLS conductors is a special designed operation conditions which cause the transformation of tensile stresses from the external aluminium base layers to the core. The conditions of this transformation are called “knee point” because a rapid change of the conductor sag - temperature relationship is observed. Prediction of conditions of the “knee point” temperature (KPT) is a key problem during overhead line design. The KPT is a function of different factors like conductor materials properties, conductor design, span parameters, sagging procedures and overhead line exploitation conditions. The paper presents an original theoretical model for HTLS conductors KPT calculations and shows some examples and comparisons of the different conductor designs and parameters.

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.

This paper presents the research results of copper Covetic metallurgical synthesis along with the characterization of cast material and the processing of casts into wires. The Cu-C composite production method was based on patent applications of Third Millennium Metals. Obtained materials were tested for their chemical composition (including Secondary Ion Mass Spectrometry (SIMS) analysis for carbon presence), mechanical properties and electrical conductivity. Measurements were also performed for wires which were first cut from obtained casts and next cold drawn into final wire form. Produced wires were tested for their mechanical and electrical properties. Electrical conductivity of wires was measured with the use of high precision Thompson's-Kelvin's bridge type device. A key objective of the research was to determine if Covetic copper has higher electrical conductivity than pure oxygen free copper.Keywords: Covetic, copper, carbon, graphene, Cu-C W ramach artykułu przedstawione zostały wyniki badań metalurgicznej syntezy miedzianego stopu typu Covetic, analizy uzyskanych odlewów oraz badań drutów uzyskanych w procesie ciągnienia. Metoda syntezy stopu Cu-C oparta została na patencie firmy Third Millennium Metals. Uzyskane odlewy przebadane zostały pod kątem ich składu chemicznego (wraz z analizą obecności węgla metodą SIMS), podstawowych własności materiałowych oraz przewodności elektrycznej. Ponadto badaniom własności wytrzymałościowych i elektrycznych poddane zostały druty, które otrzymane zostały poprzez ciągnienie z uzyskanych odlewów. Przewodność elektryczna drutów mierzona była na z wykorzystaniem mostka Thompsona -Kelvina. Celem przeprowadzonych badań było ustalenie czy miedziany kompozyt typu Covetic posiada, w formie odlewów bądź drutów, wyższą niż czysta miedź przewodność elektryczną.

All over the world, intensive research is being conducted on the development of new conductive materials to be used in power engineering. The objective of this research is to increase electrical conductivity in wire and cable materials, and consequently, to increase line current-carrying capacities and reduce losses in electric energy transfer. Today, the expectations in the power engineering sector concentrates on conductive materials with electrical conductivity higher than conductivity of base materials, i.e. aluminum. The scientific discovery of the recent years, graphene, one of carbon allotropic variants with a very high electrical and thermal conductivity and mechanical strength, creates great possibilities to design and manufacture new materials, with super-standard functional properties. Graphene, can be a new kind of “alloy additive” to aluminum, which can significantly change their electric and another properties.This article focuses attention on the possibilities of graphene and aluminum synthesis. The researches was made over the different methods of producing these materials, in particular: chemical synthesis consisting in the combination of liquid metal with graphene into a form suitable for further processing in the processes of forming into wires. The article presents the results of mechanical properties and structural studies of aluminum-graphene composites.

The paper shows a new idea of aluminium alloys. New alloys with specially selected alloying element i.e. silver have electrical conductivity similar to pure aluminium at ambient temperature and better than pure aluminium electrical conductivity at increased temperatures. Al-Ag alloys for electrical applications (mainly for electrical conductors) due to high electrical conductivity at increased temperatures at the level of the maximum conductor working temperatures give possibility of better current capacity of conductors. The experimental results of basic mechanical properties and the electric conductivity versus temperature relation are shown in the paper as well as examples of the tested material operational properties. The summary gives theoretical analysis based on examples of the potential applications of Al-Ag alloys (new conductor designs) which provide the benefits of the new solutions in comparison to traditional conductors.