Microstructure and Mechanical Properties of High Purity Aluminum Processed by Equal Channel Angular Pressing

The microstructure and mechanical properties of high purity aluminum processed by equal channel angular pressing (ECAP) after 1,2,4,8,12 and 16 passes were investigated by optical microscope (OM),transmission electron microscope (TEM) and tensile tests at room temperature.It is shown that grains could be remarkably refined with the occurrence of dynamic recovery and dynamic recrystallization during ECAP.The strength reached a maximum value after 2 passes,and then decreased with the passes,and finally approached to a saturated value.The elongation had a minimum value of 35.88% after 1 pass,then it increased with the passes and reached the similar value of annealing state after 12 passes.The strain softening was contributed to the dynamic recovery and dynamic recrystallization during ECAP process.