2425 応力依存異方拡散現象による耐熱合金劣化損傷機構の検討(S13-3 高温材料・構造の強度と破壊(3),S13 高温材料・構造の強度と破壊)

概要

論文の詳細を見る
In order to make clear the fracture and degradation mechanisms of nickel based superalloy, we studied the atomic diffusion behavior of the Ni-based superalloy by using the molecular dynamics simulation. Diffusion constant of Al and Ni atoms are increased drastically by tensile strain. In addition, X-ray diffraction technique was used to characterize the microstructure of Ni based superalloy CM247LC after a creep test at 900℃ and 216MPa. For a fatigue sample and 80% creep damaged one, the 110 L1_2 superlattice reflection peak of Ni_3Al (□' phase) vanished. From these results, we suggest that the ordered L1_2 structure of Ni_3Al changes to the disordered fcc structure by stress dependent anisotropic diffusion under high temperature creep condition.
2007-09-07