Numerical Simulation Of Extrusion Process Of Hollow Profile And Die Structure Optimization

Extrusion die plays a vital role in extrusion processing industry. The quality and service life of extrusion die are key factors that to determine the feasible of extrusion process and development of new product. Porthole die is one kind of extrusion die to produce hollow profile, and its structural parameters directly affect the quality of products. Due to the complex shape of product and high extrusion pressure, the porthole die could be damaged easily. Therefore, to ensure product quality and improve its service life, the rational design should be consider for extrusion die.In this paper, the software HyperXtrude would be adopted to simulation the extrusion processing for hollow profile and obtained the simulation results. The first case study addressed a practical problem of wall thickness attenuation during extrusion to produce a complex thin-walled hollow AZ61magnesium profile. A HyperWorks FEM software package was employed to aid in identifying the causes for the wall thickness attenuation. There are a number of known measures that may be take to lessen or eliminate non-uniform material flow during the extrusion process, including the modification of the shape, size and location of feeder ports and welding chamber and the adjustment of local bearing lengths. Five adjustments to optimize the structure of porthole die were proposed, such as the restrictive block, the height and shape of welding chamber and the interspacing between the mandrels. The wall thickness of the extrudate predicted using FEM simulation was very close to experimental measurements. Comparing the five adjustments for extrusion die, adjusting the shape of porthole could balance the metal flow and press well, thus can increase the wall thickness.At the same time, the second case for 6063 aluminium alloy hollow profile was investgated by the software HyperXtrude, too. Also studied the metal flow in different directions and the pressure distribution of welding room. The reason for defects was metal flow of different direction in the cross section. The adjustment was the restrictive block. The simulation results showed that the restrictive block could minimize the velocity difference inside the profile, so can decrease the phenomenon of concave. Comparing with the actual extrusion profiles, the forming of the profile concave amended by the restrictive block. The simulation results demonstrated the feasibility of using FEM simulation as a useful tool to solve industrial problems encountered in the production of complex profiles.