Numerical Simulation Of The Continious Extrusion Process For Rectangular Cross Section Part

Driven by the friction of the grooved wheel and the coining roll, the metal is rolled to the extrusion channel continuously, and will be extruded from the die to form the parts. During the whole process of continuous forming, the friction is set as the driving force, which avoids the harmful effects of friction in the conventional forming process, and therefore, gets many advantages for the continuous extrusion, such as high productivity, low energy consumption and high quality of the parts. So,it has been widely used in the production of wires, tubes and clad materials. But,for the complexity of the continuous extrusion, defects will be produced in the workpieces if the technological parameters and the sizes of the die cavity are not correct. Considering this situation, numerical simulation is conducted for the continuous extrusion process of a rectangular cross section aluminium busbar to get the deformation and flow information, and to provide the theoretical guide for the design of process and diesIn view of the deformation characteristic of continuous extrusion, the paper divided its deformation process into four stages, namely rolling, curving, extrusion and extrusion-out. And then, with the help of the simulation software, the continuous extrusion process of a rectangular cross section aluminium busbar was simulated and the deformation and filling information at each stage was obtained. At the same time, the deformation history and the filling change of the grooved wheel at different places of the billet were mastered by tracing the node, analyzing the cross sections and torque of the grooved wheel from unsteady deformation state to steady deformation state, by which the total deformation laws of metal were knownThe research result shows that:after the billet separates from the coining roll, it will be curved by the friction force of the extrusion groove and detaches the groove bottom, which makes the pressure stress and friction force at the bottom disappear; the metal filling in extrusion channel is inhomogeneous. The channel near the shoe is filled more, and the channel near the grooved wheel is filled less. The inhomogeneity at the abutment nearby shows more obvious; After the billet touches the abutment, with the friction force of the grooved wheel, the upsetting deformation occurs near the abutment, which makes the contact area and contact force between the billet and the grooved wheel increase rapidly. And the shear deformation zone is formed near the die, but the deformation resistances of abutment and die are just limited around them; when the billet is extruded pass the reduction strap of the die, it has the tendency to move upward due to the inhomogeneous distribution of the velocity. But then the tendency is weaken by the calibrating strap and finally disappears.