THE EFFECT OF UNLIMITED CUMULATION OF LARGE PLASTIC STRAINS ON THE STRUCTURE-SOFTENING PROCESSES OF 99.999 AL

The influence of very large deformations on the structure-softening processes in 99.999% pure aluminium was investigated. Very large strains were exerted by the cyclic extrusion-compression method in the range of true strains from 0.9 (1 cycle) to about 90 (100 cycles). It was found that a steady state appears above a true strain of 0.9, caused by the attainment of a balance of strain-hardening processes and dynamic softening processes. It was observed that after finishing the deformation, static recrystallization proceeds. The formation of new grains in the areas of band structure is a very characteristic feature of all structure-softening processes. © 1990.