Interlamellar residual stresses in single grains of NiO-ZrO2(cubic) directionally solidified eutectics

Phase-to-phase residual stresses due to thermal expansion mismatch were measured in lamellar NiO-ZrO2(cubic) directionally solidified eutectics (DSEs). The triaxial strain tensors for both phases were measured using single-crystal X-ray diffractometry techniques on isolated grains of the DSE. From the strain tensors, the stress tensors were calculated, taking into account the full elastic anisotropy of the phases. The resulting stress tensors indicated that very large compressive stresses accumulated in ZrO2 whereas large tensile stresses were amassed in NiO parallel to the lamellae during the solidification process. The large magnitudes of the stresses indicated that the interfaces between the lamellae were very well bonded and did not facilitate slip or other stress-relieving processes.