材料期刊网

The two-dimensional scattering patterns for micro-structural changes during creep observed by SAXS are different from that obtained by SANS technique. The changes in morphology and size characteristics of different regions of the secondary gamma' precipitates have been demonstrated by the variation of SAXS scattering intensity. The results show that the secondary gamma' precipitates have two types of feature sizes, which have similar trends of change during the creep process characterized by decreasing in the first and second stage and increasing in the final stage. As comparison shows, the larger gamma' precipitates have more noticeable changes. The elements of the secondary gamma' precipitates diffuse seriously in the second stage with the character of creep 15.h, the surfaces of gamma' phase are blurred, and interfaces of two-phase become clear again in the final stage. Due to the increasing size or the reducing number of the secondary gamma' phase, the total arcs of interfaces between the secondary gamma' precipitates and matrix phase then decreases.