A thermal grooving study of relative grain boundary energies of nickel in polycrystalline Ni and in a Ni/YSZ anode measured by atomic force microscopy

Grain boundary grooves of nickel were studied in Ni polycrystals and Ni/YSZ (nickel/yttria-stabilized zirconia) anode microstructures an solid oxide fuel cell (SOFC) order to determine the relative grain energies nickel. Reliable material parameters are necessary for realistic simulations model coarsening grains SOFC anodes. However, reported values literature do not meet requirements accuracy experimental conditions differ strongly from within anode. In this work, measurement approach atomic force microscopy was optimized ensure required measuring grooves; thermal grooving experiments performed at T=750?C dry humid atmosphere. The resulting distributions measured dihedral angles identical polycrystal microstructure independent annealing time humidity. For first time, precise determined with high under operating mean value ?GB/?S is 0.475±0.013 high-angle boundaries, 0.217±0.010 low-angle 0.157±0.013 ?3 boundaries 0.019±0.002 twin boundaries.