Formation study of nanostructured Cr100−xCox (x = 10, 90) alloys

Cr90Co10 and Cr10Co90 mixtures were mechanically alloyed in order to obtain nanocrystalline alloys. The obtained powders were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The structural parameters such as the lattice parameters, the crystallite size, the microstrains and the defect density of the different phases were deduced from the Rietveld refinement of the XRD patterns using the MAUD program.For the Co-rich mixture the evolution with milling time of the SEM micrographs shows a tendency of particle agglomeration. However, in the case of the Cr-rich mixture, the particles tend to the fragmentation. The Rietveld refinement of XRD patterns of the Cr10Co90 mixture reveals the formation of disordered hcp and fcc Co(Cr) solid solutions. In the case of the Cr90Co10 mixture, only a disordered bcc Cr(Co) solid solution is obtained. The changes in the morphology and the structure of the two mixtures are explained on the basis of the mechanical and structural properties.

► We investigate the composition effect on the structural parameters of Cr–Co alloys.
► Cr100−xCox (x = 10, 90) mixtures are obtained by ball milling.
► The investigation is carried out by SEM and XRD.
► The structural parameters of the obtained mixtures are different.
► This difference is explained on the basis of mechanical and structural properties.