56 research outputs found

    Influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper

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    In this study, the influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper after casting and cold deformation was investigated. It was shown that the increase in the casting speed from 0,09 m / min to 0,22 m / min resulted in refinement of the macrostructure and reduction of the crystal cross-sectional area from 3,221 mm2 to 1,2 mm2, which resulted in an increase in microhardness after casting by 8 %, while in the state after cold working, an increase in microhardness by 3 % and ultimate tensile strength by 2,5 %

    Influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper

    Get PDF
    In this study, the influence of the speed of downward semi-continuous casting on the crystal size and mechanical properties of recycled copper after casting and cold deformation was investigated. It was shown that the increase in the casting speed from 0,09 m / min to 0,22 m / min resulted in refinement of the macrostructure and reduction of the crystal cross-sectional area from 3,221 mm2 to 1,2 mm2, which resulted in an increase in microhardness after casting by 8 %, while in the state after cold working, an increase in microhardness by 3 % and ultimate tensile strength by 2,5 %

    The effect of the rolling process on selected properties of magnesium copper with microadditives

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    The article presents the results of rolling magnesium copper castings with microadditives of P, Al, Ti, and Zr. The castings were made in the process of static casting into rods with a diameter of 20 mm. The obtained castings were shaped with a 3 % draft into bars of square cross-section and rolled on a shape mill with 20 % drafts on average. Mechanical properties were determined in a static tensile test at selected degrees of plastic deformation (57,2 %, 76,9 % and 91,3 %). At the final stage of cold working of the wire rods with a total draft of 91,3 %, the microstructure and electrical conductivity were examined. The research indicates a strong influence of microadditives on the strengthening of castings in the rolling process and their electrical conductivity

    The effect of the rolling process on selected properties of magnesium copper with microadditives

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    The article presents the results of rolling magnesium copper castings with microadditives of P, Al, Ti, and Zr. The castings were made in the process of static casting into rods with a diameter of 20 mm. The obtained castings were shaped with a 3 % draft into bars of square cross-section and rolled on a shape mill with 20 % drafts on average. Mechanical properties were determined in a static tensile test at selected degrees of plastic deformation (57,2 %, 76,9 % and 91,3 %). At the final stage of cold working of the wire rods with a total draft of 91,3 %, the microstructure and electrical conductivity were examined. The research indicates a strong influence of microadditives on the strengthening of castings in the rolling process and their electrical conductivity

    Effect of plastic deformation on the structure and texture of CuSn6 alloy

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    This paper presents the results of study in the structure and texture CuSn6 alloy deformed in the RCS (repetitive corrugation and straightening) process. Investigated the influence of process parameters on the above property. The obtained results were correlated with the results of the alloy subjected to cold rolling

    Atomic scale investigation of Cr precipitation in copper

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    The early stage of the chromium precipitation in copper was analyzed at the atomic scale by Atom Probe Tomography (APT). Quantitative data about the precipitate size, 3D shape, density, composition and volume fraction were obtained in a Cu-1Cr-0.1Zr (wt.%) commercial alloy aged at 713K. Surprisingly, nanoscaled precipitates exhibit various shapes (spherical, plates and ellipsoid) and contain a large amount of Cu (up to 50%), in contradiction with the equilibrium Cu-Cr phase diagram. APT data also show that some impurities (Fe) may segregate along Cu/Cr interfaces. The concomitant evolution of the precipitate shape and composition as a function of the aging time is discussed. A special emphasis is given on the competition between interfacial and elastic energy and on the role of Fe segregation

    Grain refinement of deoxidized copper

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    This study reports the current status of grain refinement of copper accompanied in particular by a critical appraisal of grain refinement of phosphorus-deoxidized, high residual P (DHP) copper microalloyed with 150 ppm Ag. Some deviations exist in terms of the growth restriction factor (Q) framework, on the basis of empirical evidence reported in the literature for grain size measurements of copper with individual additions of 0.05, 0.1, and 0.5 wt pct of Mo, In, Sn, Bi, Sb, Pb, and Se, cast under a protective atmosphere of pure Ar and water quenching. The columnar-to-equiaxed transition (CET) has been observed in copper, with an individual addition of 0.4B and with combined additions of 0.4Zr-0.04P and 0.4Zr-0.04P-0.015Ag and, in a previous study, with combined additions of 0.1Ag-0.069P (in wt pct). CETs in these B- and Zr-treated casts have been ascribed to changes in the morphology and chemistry of particles, concurrently in association with free solute type and availability. No further grain-refining action was observed due to microalloying additions of B, Mg, Ca, Zr, Ti, Mn, In, Fe, and Zn (~0.1 wt pct) with respect to DHP-Cu microalloyed with Ag, and therefore are no longer relevant for the casting conditions studied. The critical microalloying element for grain size control in deoxidized copper and in particular DHP-Cu is Ag

    Microstructure and Properties of Multifibre Composites

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    In the study microstructure and properties of composite multifibre copper-base wires are presented. A decision was made to produce wires with “soft” fibres (Al) and “hard” fibres (Fe). In the study the phenomenon occurring on the border of Al-Cu was also analysed. The produced Cu-Al and Cu-Fe composites presented ordered microstructure with the fibres uniformly distributed in the copper matrix. The composites underwent plastic consolidation to the degree which provided satisfactory mechanical and electrical properties. During the drawing the fibres deformed proportionally with copper matrix therefore their content in the cross section remained unchanged

    Mechanizm i kinetyka wydzielenia w wybranych stopach miedzi

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    The required functional characteristics expected from copper alloys have a major impact on the technological production process, therefore there is a strong need to acquire knowledge on changes of properties with technological process including heat treatment and plastic working. The studied in this work copper CuTi4. CuFe2. CuCr0.7 and CuNi2Si1 alloys was selected to present differences in hardening phases .The samples were quenched, cold deformed (rolling), and aged. Detailed microstructure analysis and its influence on electrical and mechanical properties was presented in the work. Quenched CuTi4, CuFe2, CuCr0.7 and CuNi2Si1alloys have different mechanism and kinetics of precipitation during aging. These processes are complex and depend on the heterogeneity of distribution of alloying elements in copper matrix, the process parameters and cold strain value.Wymagane cechy użytkowe których oczekuje się od stopów miedzi wywierają zasadniczy wpływ na ich technologiczny proces wytwarzania. Wynika stąd konieczność rozeznania zakresu zmian własności użytkowych wynikających z zastosowanego wariantu obróbki cieplnej i plastycznej. Stopy miedzi CuTi4, CuFe2, CuCr0.7 i CuNi2Sil poddane badaniu w niniejszej pracy dobrano w ten sposób aby różniły się fazami umacniającymi. Próbki poddano przesycaniu, odkształceniu na zimno (walcowanie) oraz starzeniu. Przesycone stopy CuTi4, CuFe2. CuCr0.7 oraz CuNi2Sil różnią się mechanizmem i kinetyką wydzielania podczas procesu starzenia. Procesy te są złożone i uzależnione od niejednorodności rozmieszczenia składników stopowych w osnowie miedzianej, historii wytwarzania i przetwarzania stopów, parametrów przesycania i starzenia jak tez wielkości odkształcenia na zimno
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