Abstract:Aiming to analyze the serious earing defects in initial extrusion process of aluminum controller housing, simulation was carried out by DEFORM-3D and the results showed a good agreement with the experimental work. Based on the simulation results, it is easy to find that the non-uniform velocity of metal flow is the main cause leading to earing defects. Therefore, a novel process scheme which tried to avoid the defects by using a punch with a group of resistance ribs at the bottom was put forward. For further study, the orthogonal experiment method was adopted to optimize the novel process. The width of the rib d, the thickness of the rib t, the length of the longest rib L and the inclination angle α were selected as design variables, and the height difference Dh along the top edge of the controller housing after extrusion which could reflect the earing was determined as the optimized objective. Finally, the optimized scheme was obtained. Compared with the initial process, the height difference Dh was reduced to 3.32 mm from 14.09 mm and the earing defects have been obviously improved in the optimized scheme.

Key words: controller housing; extrusion; earing defects; FE simulation; optimization