THE STRUCTURE-BASED DESIGN OF METAL-FORMING OPERATIONS

The work summarizes the recent experimental studies and theoretical considerations on the nature of plastic deformation in metallic materials. Specifically, it concentrates upon the rules which the heterogeneous deformation obeys and which differ radically from those of the homogeneous deformation. Formulation of such rules is based upon the experiments which provide the very fundamental information about the criterion of slip in crystalline materials, choice and sequence of operation of slip systems and conditions under which ''crystallographically determined'' slip may be replaced by transgranular shear. The correlation of this form of slip with metal structure and global mechanical properties is given. The results of the studies allow to predict the onset of heterogeneous mode of deformation and what is even more important, they show the means due to which the mode of deformation may have taken under control. The very practical aspect of the work consists itself in the concept ''of the structure based design'' of metal forming operation. It is shown, that the scheme and sequence of straining in a particular forming operation appears extremely important from the point of view of the energy consumption of the process and the final structure of the metal. The examples of ''energy saving'' metal forming operations, designed according to the concept, are presented.