Metal flowing behaviors during diplopore extrusion of square tube with porthole die

Applying welding plane meshes repairing technology based on reverse engineering and commercial FEM soft Deform-3D, a three dimensions finite element method for simulating the whole diplopore extrusion process of square tube with porthole die, including bonding stage, were developed. The effects of the portholes configuration scheme on the metal flowing behaviors, extrusion load, tube temperature and forming quality were analyzed. The results show that, the area ratio of the center to the side porthole (Q1/Q2) is an important factor affecting the flow uniformity, seam position and straightness of the tube. When the area ratio (Q1/Q2) ranges in 0.93-1.03, the straightness of the extrusion tube is satisfied. The diameter ratio of the porthole circumcircle to the extrusion container (Dc/D) has little effect on the temperature-rising, but has great effect on the extrusion load. When the diameter ratio is 0.82, the extrusion load is at minimum. When the diameter ratio is larger than 0.82, the extrusion load increases obviously.