Structural and Analytical Evaluation of the Strain Intensity and its Components During Cross-Roll Piercing at Different Feed Angles

Resumo

Strain intensity and its components during cross-roll piercing at different feed angles were evaluated using a combined structural/analytical method. Commercially pure aluminum ingots of 60 mm diameter and 300 mm length were pierced to produce shells of 64.6 ± 0.5 mm diameter and 21.3 mm wall thickness at feed angles of 10, 12, 14, 16, and 18°. It was established that the shear component of strain intensity responsible for the formation of helical fiber macrostructure is predominant. The distribution of strain intensity through the wall thickness is characterized by a significant gradient that decreases as the feed angle increases. The feed angle is an effective factor that controls the process and determines the magnitude of strain intensity (its shear and linear components) and its uniform distribution throughout the wall thickness.