%0 Journal Article
%T Electron microscopy characterization of mechanically alloyed and hot consolidates Cu-Cr<sub>3</sub>C<sub>2</sub> particles
%A L¨®pez
%A M.
%A Camurri
%A C.
%A Vergara
%A V.
%A Jim¨¦nez
%A J. A.
%J Revista de Metalurgia
%D 2005
%I Consejo Superior de Investigaciones Cient¨ªficas
%X Mechanically alloyed copper-ceramic composites have been obtained with the purpose of studying their use as copper-based material for electrical equipment. For high-temperature applications, dispersion-strengthened copper alloys are attractive due to their excellent combination of thermal and electrical conductivity, mechanical strength retention and microstructural stability. In this work, powder mixtures of pure copper with 2 vol % Cr3C2, milled during 4, 6, 10, 12 and 15 h in a high-energy planetary balls mill under argon atmosphere, were consolidated by hot isostatic pressing, applying a pressure of 100 MPa at 1073 K for two hours, to obtain materials with a fine microstructure. The Cu-Cr3C2 alloys were studied by scanning electron microscopy (SEM), electron microprobe (EPMA) and transmission electron microscopy (TEM). Mechanical properties and electrical conductivity were also studied. The average tensile strength and electrical conductivity were found to be 500 MPa and 50 % IACS, respectively. The Cr3C2 ceramics show good stability during hot consolidation. Contributing to a further strengthening of the alloy during the hot consolidation, uniformly-distributed Fe-carbide particles of nanometric size precipitated in the copper matrix. Fe-Cr oxycarbides formed in the interphase between Cr3C2 particles and the copper matrix cause the low ductility of Cu-Cr3C2 alloys. Said particles are attributed to impurities/contamination generated from the milling process. Se obtuvieron aleaciones compuestas de Cu-Cr3C2, aleadas mec¨¢nicamente, para estudiar futuras aplicaciones en componentes el¨¦ctricos. A altas temperaturas, las aleaciones de base cobre reforzadas por dispersi¨®n, son atractivas por su excelente conductividad t¨¦rmica y el¨¦ctrica, propiedades mec¨¢nicas y estabilidad microstructural. En este estudio, mezclas de polvo de cobre puro con un 2 % en vol. de Cr3C2, obtenidas mediante molienda en un molino de bolas planetario de alta energ¨ªa, durante 4, 6, 10, 12 y 15 h, se compactaron isost¨¢ticamente en caliente a 1.073 K durante 2 h con una presi¨®n de 100 MPa en arg¨®n, para obtener un material con una microestructura fina. Las aleaciones de Cu-Cr3C2 se estudiaron mediante microscop¨ªa electr¨®nica de barrido MEB y de transmisi¨®n MET, adem¨¢s de microsonda electr¨®nica. Tambi¨¦n, se caracterizaron las propiedades mec¨¢nicas y la conductividad el¨¦ctrica, obteni¨¦ndose valores de 500 MPa y 50 % IACS, respectivamente. Las cer¨¢micas de Cr3C2 presentan una buena estabilidad durante la compactaci¨®n en caliente. Se observ¨® la precipitaci¨®n de part¨ªculas de tama o nanom
%K Mechanical alloying
%K copper-ceramics
%K composites
%K properties
%K Cobre-cer¨¢micas
%K compuestos
%K aleado mec¨¢nico
%K propiedades
%U http://revistademetalurgia.revistas.csic.es/index.php/revistademetalurgia/article/view/219/375