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.
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.
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.
Modern manufacturing technologies of flat cold-rolled products made of aluminium and its alloys are based on raw materials produced with the use of continuous casting technology. One of the most frequently used integrated production processes, based on continuous casting of metal, is twin roll casting method (TRC). In TRC method liquid metal flows into the area formed by two water-cooled rolls, solidifies and next is deformed (rolled) which allows to obtain strip with several millimetres thickness. Thanks to this, it is possible to eliminate hot rolling stage from the typical production technology, and directly subject obtained sheets to cold rolling process.This paper presents results of cold rolling strain dependency on the mechanical properties of tested aluminium alloys from 1XXX, 3XXX and 8XXX series, produced in the laboratory conditions with the use of TRC method. Furthermore the rolling loads and basic mechanical properties, determined in an uniaxial tensile, were examined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.