Research On Numerical Analysis Of Hollow Profile Aluminum Extrusion Process And Optimization Of Die Bearing

People are looking for new ways of sustainable development, and the lightweight is being paid more and more attention since it is an effective way to reduce energy consumption. Due to its high strength, corrosion-resistance, low-density and good electrical conductivity, aluminium alloy is become the preferred material for lightweight, nowadays, it is widely used in traffic, construction, automotive, shipbuilding and other fields. Extrusion is an important way in Aluminum alloy process engineering, however, the structure of extrusion die and the process parameters have great influence on the products quality, in order to take parameter determination, designers should have rich practical experience, after many times of modifications and experiments, they can obtain acceptable product, this will serious restrict the development of our country in the field of aluminum profile. With the application of numerical simulation technology, People can find defects in the design in advance so that designer can correct it through the simulation results and obtain the acceptable solution.At first, the basic principle of arbitrary Lagrangian-Eulerian method is expounded and introduces the HyperXtrude which is based on arbitrary Lagrangian-Eulerian algorithm, describes the function, boundary condition, calculation process, the steady state assumption. In addition, taking a hollow aluminum profile which is hard to extrude as an example, simulate and analyze the extrusion process, in order to solve the problem of inhomogeneous flow velocity of extrusion process, the lower die structure is modified and the bearing length is optimized, the deformation of profile is effectively reduced after optimization.secondly, in order to respectively research and discuss the extrusion velocity, billet preheating temperature, die preheating temperature on the effects of extrusion process, the simulation schemes are formulated. The results show that reducing the extrusion velocity and improving the preheating temperature of die and billet can effectively reduce the extrusion pressure and the flow stress, if the extrusion velocity is high, the intensity of uneven velocity and die stress will increase, easily cause the die scrap. Improving the preheating temperature of die and billet, the uniformity of metal flow is improved, the preheating temperature of billet causes little impact to the temperature of die and profile. The highest temperature of profile and die will decrease and the temperature distribution will become more uniform, which has been achieved by preheating the die to a higher temperature.Finally, the influences of welding chamber depth and welding angle on extrusion process were analyzed, It conclude that, with increasing the welding chamber depth, the extrusion pressure, die stress, maximal offset of die mandrel increase,and there is an best depth for the welding chamber to make the metal flow more uniform than others, the change of welding angle can influence the stability of die mandrel and the extrusion force.Then,selecting the length of die bearing as the design variables, using the adaptive response surface method to optimize the length of die bearing,the optimization result show that the velocity of profile is more uniform than before,and the deformation of profile become much smaller.