THE STRUCTURE-BASED DESIGN OF METAL-FORMING OPERATIONS

The work summarizes the recent experimental studies and theoretical co nsiderations on the nature of plastic deformation in metallic material s. Specifically, it concentrates upon the rules which the heterogeneou s deformation obeys and which differ radically from those of the homog eneous deformation. Formulation of such rules is based upon the experi ments which provide the very fundamental information about the criteri on of slip in crystalline materials, choice and sequence of operation of slip systems and conditions under which ''crystallographically dete rmined'' slip may be replaced by transgranular shear. The correlation of this form of slip with metal structure and global mechanical proper ties is given. The results of the studies allow to predict the onset o f heterogeneous mode of deformation and what is even more important, t hey 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 oper ation. It is shown, that the scheme and sequence of straining in a par ticular forming operation appears extremely important from the point o f view of the energy consumption of the process and the final structur e of the metal. The examples of ''energy saving'' metal forming operat ions, designed according to the concept, are presented.