The production technology and properties of an aluminum alloy processed by equal channel angular pressing

Distribution of equivalent stress and equivalent strain was analyzed in the ECAP process based on material flow laws. Simulation results showed that severe plastic deformation occurred at the corner of the cavity, indicating a stress concentration at the equal channel angle. Distribution of stress and strain at the same section was not uniform. Equivalent stresses on the surface at the inside corner of the part were larger. Experimental results showed that forming speed and lubrication conditions had a great influence on quality of parts. The parts were in good condition with no wrinkle and rupture after ten ECAP passes. EBSD analyses showed that the original coarse grains were refined and uniformly distributed, and the average grain size of the cross section was about 620 nm after ten ECAP passes. With increasing the number of ECAP passes, the proportion of small angle grain boundaries decreased gradually and the ratio of large angle grain boundaries increased. Tensile strength and hardness increased sharply, while the elongation decreased sharply after the first ECAP pass. With succeeding the ECAP passes, the tensile strength, hardness and the elongation all increased slowly.