2007 年 48 巻 562 号 p. 1007-1011
Compressive torsion processing(CTP), in which compressive and torsional loadings are applied to cylindrical specimens simultaneously, has the great advantage of providing severe plastic deformation without a change in specimen shape. In this work, CTP is applied to pure aluminum to investigate the effects of processing temperature and specimen diameter on the grain refinement and microstructure homogeneity of a processed specimen. As a result, a lower processing temperature was found to be more effective for obtaining a fine grain size, but was not useful for obtaining homogeneous grain refinement. Increasing the specimen diameter was effective for obtaining homogeneous grain refinement. Grains less than 3 μm in size were observed in room-temperature processing, but the grain size increased with increasing processing temperature.