Skip to Main content Skip to Navigation
Theses

Étude du mélange à l'état solide lors de la mécanosynthèse d'alliages Fe-X (X = CR, MN, V, MO) et étude de la mise en ordre d'alliages Fe-V élaborés par cette technique

Abstract : The evolutions of Fe-X (X=Cr,Mn,V,Mo) elemental powders mixtures during mechanical alloying have been characterized from the scale of the powder particle down to the atomic scale by laser granulometry, scanning electron microscopy, microprobe analysis, X-ray and neutron diffraction, Mossbauer spectroscopy and magnetic and susceptibility measurements. When the thermodynamic evolution of the system leads to mixing (Fe0.28Mn0.72), the combination of the elements is faster th an when it leads to unmixing (Fe0.30Cr0.70).In our milling conditions, the stationary state of Fe0.30Cr0.70 powders mixture is not a homogeneous solid solution but presents nanosized composition fluctuations. These results can only be explained in the light of a competition between a driven mixing mechanism and a thermal unmixing process. During mechanical alloying of Fe0.30Mo0.70 and Fe0.66Mo0.34 powder mixtures, an amorphous phase is formed at the interfaces between the Fe and Mo layers. This amorphisation seems to be due to the asymmetry of the diffusion coefficients of Fe and Mo added to a destabilization of the crystalline lattice linked to the driven mixing of the elements beyond a critical concentration. The ordering (A2-+B2) under annealing of Fe-V alloys synthesized by mechanical alloying has been studied by neutrons diffraction and Mossbauer spectroscopy. At 450°C, the order parameter of Fe0.53 V0.47 stabilizes at an unusual low value that can be attributed residual fragments of antiphase boundaries. Only high enough temperatures can lead to the elimination of these defects thanks to long range migration of vacancies. An A2+B2 two phase domain, predicted by the theory, has been observed in Fe0.37V0.63 alloy annealed at 450°C.
Document type :
Theses
Complete list of metadata

https://hal.univ-lorraine.fr/tel-01749949
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 12:34:03 PM
Last modification on : Thursday, March 25, 2021 - 3:01:43 AM
Long-term archiving on: : Friday, September 14, 2018 - 10:07:02 PM

File

INPL_T_2000_ZILLER_T.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01749949, version 1

Collections

Citation

Tiffany Ziller. Étude du mélange à l'état solide lors de la mécanosynthèse d'alliages Fe-X (X = CR, MN, V, MO) et étude de la mise en ordre d'alliages Fe-V élaborés par cette technique. Autre. Institut National Polytechnique de Lorraine, 2000. Français. ⟨NNT : 2000INPL135N⟩. ⟨tel-01749949⟩

Share

Metrics

Record views

71

Files downloads

77