TEM and EBSD investigation of a Re-doped β-NiAl coating on a Ni-based single crystal superalloy

Abstract To figure out the microstructure and precipitation phases of a Re doped β-NiAl coating, the electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were both used. Re-doped β-NiAl coating was composed of outer coarser β-NiAl grains with nanometer sized γ-Re precipitates, inner tiny β-NiAl grains with submicron sized α-W phases and bottom interdiffusion zone (IDZ, consisted of strip TCP and β-NiAl phases). Moreover, these γ-Re and α-W nanoparticle phases were not only aggregated at β-NiAl grain boundary but also appeared within the grains.