Physical meaning of creep damage parameters evaluated from distribution of grain boundary cavities on cross-section
Tada Naoya; Kitamura Takayuki; Ohtani Ryuichi
Abstract:In order to grasp the creep damage of polycrystalline heat-resisting alloys, creep damage parameters observed on the cross-section, such as the area fraction of cavities. A-parameter, fraction of cavities on grain boundary lines and the number of cavities in unit area, have frequently been used. Although they include the information of creep cavities, it is vague what they really represent in the spatial distribution of cavities. In this paper, the physical meaning of these parameters is investigated using a model distribution of cavities, and the dependences of parameters on the radius of cavities, on the number of cavities on each grain boundary facet, and on grain diameter are discussed. Key Words:creep damage parameter, grain boundary cavity, observation on cross-section, spatial distribution, physical meaning, probabilistic analysis