Research On Numerical Simulation Of Aluminum Profile Forward Extrusion Process And Structure Optimization Of Die

Having the advantages of light weight, high strength, beautifulappearance, good comprehensive performance and so on, aluminumextrusion products are widely used. Extrusion process design play animportant role in realizing aluminum extrusion, however, in the processof production, the design of the mold and the determination of processparameters are mainly dependent on the workers’ experience actually.This traditional method is able to obtain acceptable product after manytimes of modifications and experiments, while, which largely restrict thedevelopment pace of aluminum profile industry. With the development ofcomputer technology, it becomes a key tool to study on the extrusion law,die design and structure optimization that use numerical simulationtechnology gradually.The numerical simulation method is used to research the steadyextrusion process for porthole die in this paper. Firstly, the structure sizeof the porthole die are designed according to the profile’s characteristicsand the design principles of the porthole die, which offer a die structuralfoundation for aluminum profile production; The finite element softwareHyperXtrude, which is based on ALE algorithm, is used to simulate theextrusion process. The key structural parameters of die, such as hole, leadflow hole, lead chute, double-step welding chamber and bearing length,etc., are optimization for the problem of nonuniform flow velocity ofextrusion process. The results show that the strength of the die can beguaranteed, the flow velocity of extrusion profiles is uniform and thedeformation is small.Secondly, the simulation schemes are formulated to research anddiscuss the effects of extrusion speed, die preheating temperature andextrusion ratio on extrusion process of simple profile. The results showthat selecting low extrusion velocity is favorable for the uniform of flowvelocity, the temperature distribution uniform and the reduction of diestress, on the premise that the production efficiency and profile temperature no exceeding550degrees the maximum temperature ofAA6063aluminum alloy are guaranteed; The lower of the die preheatingtemperature, the bigger of the extrusion pressure will be, which appearsextrusion stuffy car easily. While die is preheated to a higher temperature,the metal flow uniform can be improved, and the extrusion pressure, flowstress and die stress are decreased; When extrusion ratio is too small ortoo large, there are not beneficial effects to improve the metal flowuniform and service life of extrusion die. And taking the large profile asan example, the three process parameters on the effect of the complexprofile extrusion process is discussed, it found that the law is the same asthe simple profile.Finally, the effects of multi-hole die structures which include thewelding chamber structure and the distance of mold core on extrusionprocess are discussed. It concludes that three-step welding chamber caneffectively control the uniformity law of metal flow. Then by changingthe three heights of three-step welding chamber respectively, it’s foundthat the flow of metal is the best performance when three heights areequal, the forward die takes second place, and the back die is the worst.This illustrates that it’s very important to determine the height ofthree-step welding chamber, otherwise, it’s the opposite; With theincreasing of welding chamber step, the weld quality is improved, but itneeds more energy consumption to extrusion in practice. In addition, thedistance of mold core is too large or too small will produce the lateraldeviation, so as to the hardly guarantee of mold core stability, the diestrength and the accuracy of the profile size.