Mobilité des défauts à différentes températures dans les superalliages base Nickel

Abstract
Nickel Based superalloys are multiphased materials consisting in long range ordered γ' cuboïdal precipitates (L1₂ structure) embeded in γ matrix chanels. In situ deformation experiments in a Transmission Electron Microscop have been performed in order to study the defect mobility. This technique allows the observation of the dislocations dynamics under controlled conditions of stress and temperature. The microscopic mechanisms controling the deformation of each phase (γ and γ') have been analaysed. The role of these mechanisms in the global deformation of the material is discussed.