The development of grain-boundary misorientations, with an evolving axial texture, during directional solidification was examined by applying electron back-scattered diffraction techniques to Ni-based superalloys (CMSX4, CMI86LC). A preferred grain-boundary misorientation distribution, for a sharp (001) axial texture in CMI86LC was associated with a clustering of misorientation axes in the vicinity of (001). This was accompanied by an enhanced distribution of coincidence site lattice boundaries. An increased incidence of low-angle boundaries was attributed to the existence of preferred misorientation axes and to accommodation by secondary intrinsic grain-boundary dislocations. A more diffuse (001) axial texture in CMSX4 was associated with a significant proportion of misorientation axes which deviated from (001), and a marked reduction in the proportion of CSL boundaries.

Directional and Single-Crystal Solidification of Ni-Base Superalloys II - Coincidence Site Lattice Character of Grain Boundaries. M.G.Ardakani, N.D’Souza, B.A.Shollock, M.McLean: Metallurgical and Materials Transactions A, 2000, 31[11], 2887-93