Structural and thermal study of nanostructured Cr80Co10Si10 mixture

• Amorphous and bcc-Cr(Co, Si) solid solution are obtained after 24 h of milling.
• DSC gives evidence of relaxation and crystallization of the disordered mixture.
• The crystallization of the powder results in the formation of a ternary σ phase.
• The activation energy of crystallization was calculated.

Structural evolution during milling process of Cr80Co10Si10 (wt.%) mixture was followed by the combination of the scanning electron microscopy (SEM) and X-ray diffraction (XRD). The structural parameters of different phases were deduced from the Rietveld refinement of the XRD patterns using the MAUD program. The thermal stability of the obtained powders was investigated by the differential scanning calorimetry (DSC). The Rietveld refinement of XRD patterns shows that the obtained mixture after 24 h of milling consists in nanocrystalline bcc-Cr(Co, Si) solid solution and amorphous-like phase. The DSC scans give evidence of exothermic reactions corresponding to structural relaxation, grain growth and crystallization of the disordered mixture. The annealing of the 24 h-milled powders induces the crystallization of the amorphous part of the mixture. The activation energy determined from Kissenger’s model is found to be 259.36 ± 11.16 kJ/mol.

This work deals with the structural study and thermal stability of the nanostructured Cr80Co10Si10 alloy obtained by ball milling. The obtained mixture was characterized with scanning electron microsope, X-ray diffraction and differential scanning calorimetry. The structural parameters are determined from a detailed analysis of the X-ray diffraction profiles using Rietveld method. The Kissneger’s formalism is used to estimate the activation energy of the crystallization.Figure optionsDownload as PowerPoint slide