Caracterizacion microestructural de las aleaciones base cobre Cu ₉₅Co₅ y Cu₉₀Co₅Ni₅ obtenidas por aleado mecanico y sinterizacion

The magneto-resistant properties of nanostructured Cu₉₅Co ₅ y Co₉₀Co₅-Ni₅ alloys show their interesting in candidature for multiple applications. The alloys were obtained by mechanical alloying using a planetary mill with rotational speed of 155rpm under argon atmosphere for 30, 45 and 60h as milling time. The magnetic properties obtained at 300K as a function of milling time reveals that the Cu-Co-Ni alloys show super-paramagnetism behaviour. The XRD analysis indicates that the Ms decreasing is due to the reduction copper oxide and Co structural changes from Co-fcc to Co-hc. An additional strengthening on the grain structure by alloys consolidation have the formation of CuNi solid solutions and precipitations of magnetic domains Co nanoparticles under 1nm in grain size. The SEM observation of CuCoNi alloys with the comparison of CuCo alloys shows the less phase segregation and it is attributed to the complete solubility of Ni in copper.