Stacking faults and phase transformations study in ball milled Co100

Stacking faults and phase transformations study in ball milled
Co100-X Crx(x = 0, 20, 50) alloys
S. Louidi1,2,*, F. Z. Bentayeb2 , J. J. Suñol3 .
1
Département des Sciences de la Matière, Facultés des Sciences, Université 20 Août 1955,
B.P 26 Skikda, Algérie.
2
Laboratoire de Magnétisme et de Spectroscopie des Solides LM2S, Département de
Physique, Faculté des Sciences, Université Badji-Mokhtar, B.P 12, 23000 Annaba, Algérie.
3
Dep. De Fisica, Universitat de Girona, Campus de Montitlivi, Girona 17071, Spain.
*
Corresponding author:[email protected]
Abstract :
The structural evolution and the phase transformations occurred during milling process of
Co100-xCrx (x = 0, 20, 50) alloys are investigated by X-ray diffraction. Microstructural
parameters such as the crystallites size, the microstrains, the stacking faults, the dislocation
density and the phase fraction were determined from the Rietveld refinement of the X-ray
diffraction profiles. The results show the formation of nanostructured alloys which depend on
the initial composition of the mixture. In addition, X-ray diffraction indicates that the ball
milling induces the fcc to hcp phase transformation in the first stage of milling and the reverse
hcp to fcc phase transformation at the end of milling. On the basis of Warren's model, these
allotropic transformations were explained by the presence of dislocations and the
accumulation of stacking faults in the hcp and the fcc structures.
Keywords: X-ray diffraction ; Rietveld refinement ; Stacking faults ; Phase transformations