Simulation For Hot Extrusion Of Cone Component And Research For Optimization Of Designing Of Dies

In this paper, the major research object is the 2A12 aluminum alloy cone component with thin wall and centrosymmetric structure. Its general size is rather big but the wall is relatively very thin. The bottom edge of top ring has different lengths inside and outside so that defects may appear in the process of forming. The small hollow circular truncated cone on the front is difficult to form. The component also has some requirements on its strength. This paper finally adopts hot extrusion forming process and does some research, optimization and practices on the method at last.After analyzing the shape and structure of the component, the shape and size of forming product is designed according to which original blank and die and combined extrusion are determined. On the basis of materials property and past experiences, the ranges of extrusion process parameters are determined, such as extrusion speed, extrusion temperature and friction coefficient.DEFORM-3D software is used in numerical simulation of the extrusion process after model building. The forming results of different blanks, extrusion temperature, extrusion speed and friction coefficient are analysed and compared to explore metal flowing regularities, distribution of stress and strain and load variation. According to the results, the most reasonable parameters are determined.The results show that: The requisite load of ducting blank is 500 kN smaller than columnar blank with same size and the distribution of strain is smoother. When the thickness is the same, the smaller the radius of ducting blank is, the smaller the load is and the worse the characteristics of forming product are. With the rise of temperature, the properties become more and more smoother and the load becomes more and more smaller. The load of 480℃ is 1250 kN smaller than 400℃. With the increase of speed, the flowing of metal becomes more and more uneven while the load becomes more and more bigger. The load of 25mm/s is 670 kN bigger than 6mm/s. The component can’t be formed when the friction coefficient is smaller than one value. When the value is bigger than this, the bigger the friction coefficient is, the larger the load is and the more uneven the distribution of stress is. The load of 0.3 is 1600 kN bigger than 0.15.The die stress of extrusion forming process was analyzed before and after optimizing by the results of numerical simulation. The results show that: it can decrease the maximum of the general effective strain by 100 Mpa and the value of the top part substantially while it can also make the distribution of the effective strain smoother after changing the front part of into cone. This can protect the damageable part of top die and increase the service life. The stress maximum of the whole die is in the bottom die and among the allowable range. The practical experiment is done according to the definite process method. The forming product is smooth while the shape and size meet the requirement. It also has satisfactory strength and high performance in the test of mechanical properties. All these prove the accuracy of the simulation results and the validity of designed dies.