Dislocation Arrangements in Cyclically Strained Inconel 713LC

INCONEL 713 LC is a cast polycrystalline superalloy used to produce turbine wheels of small internal-combustion turbines [

1

]. The dislocation structure, which is formed in the material during cyclic loading, is closely connected with fatigue damage of the material. The fatigue processes of numerous structural materials in the initial stage are characterized by heterogeneous dislocation configuration that becomes unstable during cycling. Localized bands with a specific substructure are formed. Due to the localized deformation the characteristic surface relief is developed and subsequently fatigue cracks are initiated [

2

]. In the studies of the dislocation structures of CSMX4 single crystal the specific dislocation arrangement corresponding to cyclic strain localization was observed only recently [

3

]. The aim of this contribution is to study the dislocation arrangement of INCONEL 713 LC cyclically strained in symmetrical cycling at room and high temperatures. The work is a part of a complex project directed to the relationship between the internal structure, the stress-strain response and the fatigue life of polycrystalline nickel base superalloys [

1

,

4

].