Experimental investigation of cold metal shaping of circular tubes into a semicircular section

This article investigates a new method of cold metal forming of aluminum tubes into semicircular sections, experimentally. For this purpose, some circular tubes were prepared and compressed between a rigid platen and a semicircular die in the lateral direction. The dies were machined by a CNC apparatus from the hardened steel; so, the dies are considered as a rigid body in comparison with the specimens. Four tubes with different outer diameters were shaped into the semicircular section profiles to study effects of tube diameter on the final product geometry and value of forming energy. For all the specimens, diagrams of forming energy versus lateral displacement were sketched. Also, the final shapes of the produced profile cross-section were compared. The results showed that final cross-section of the produced profiles is more similar to the desirable shape when tube diameter decrease; and undesirable curvature is considered in the specimens with larger diameters.