MEASUREMENT AMD ANALYSIS OF MICRO-CREEP DEFORMATION USING ELECTRON MOIRE METHOD

摘要

The local deformations in creep of pure copper and 321 stainless steel specimens were measured and analyzed using an electron Moire Method. This Moire method, using the electron beam lithography and the electron beam scan, makes it possible to measure the deformation in the directions parallel and perpendicular to the stress axis with high accuracy and to observe the scanning electron microscope image at the same time. The measurements show that the local deformation after the middle of the secondary creep is non-uniform, while the deformation up to the beginning of the secondary creep is comparatively uniform. As the creep deformation proceeds, the distribution of strain becomes non-uniform even in a same grain of the specimen. The analyses of the strain suggest that the no uniform deformation is caused mainly by the grain boundary sliding.