MICROSTRUCTURE/PROPERTIES RELATIONSHIP IN ULTRAFINE GRAINED ALUMINIUM PROCESSED BY ECAP TACHNIQUE

Experiments were conducted on pure ultrafine grained aluminium processed by severe plastic deformation using the equal ů channel angular pressing ů ECAP technique. By this technique bulk ultrafine grained material was prepared. The propertis of this material considerably differs from properties of material with standard grain size. It was found that microstructure of ultrafine grained aluminium after one pass by the ECAP die contains subgrains and these subgrains are changed by subsequent ECAP passes in grains separated by high angle grain boundaries. In this work special attention is given to the stability of microstructure and the relationship between microstructure and mechanical properties of ECAP material