Forging Process Numerical Simulation&Experiment Research Of AZ80Magnesium Alloy Wheel

CITIC Dicastal Co.Ltd is the largest Al-Alloy wheel manufacturer in the world.Forging process-one of3kinds main Al-Alloy production processes-is showed as:Heating—billet—Block forging—finish forging—trimmingWith the characteristics of low density, high specific strength, high specific stiffness,high thermal conductivity, and good dimensional stability, Mg-Alloy—which is praised as“the21th century’s green engineering material”—become a new technology and newresearch direction for our company，and be valued by company leaders.In this paper, using FEA simulation software, we have done the numerical analysis ofthe forging process of the AZ80Mg alloy wheel, and completed the following theoreticaland experimental research.1. The result of the numerical analysis, shows that:1) The temp. arrangement is area distribution: core metal has the highest temp.,because it doesn’t contact with die which leading to zero thermal transfer;The temp. of the billet surface is lower than the core metal, because of heatconduction after contacting with the die;2) The partial temp. of the deforming metal goes up in the wrought process, while inother most part, the temp. goes down. The forced areas of the billet are different. Thestress on the window is much higher, making the window the main deforming area, andthe defects appear more easily on the round angle of the window. Stress on other parts ismuch lower. The spoke and flange of the wheel appears less deformation during the wholeprocess, which means defects less happens in these districts.2. The distribution rule of billet metal flowing in the forging process of Mg alloywheel:1) in the initial period, the metal goes from windows to the spoke along the side ofbottom die window.2) With down-motion of the up die, metal flowing speeds up in the window, andmetal goes through plastic deformation and forms the spoke and flange. When the flange’s forming has done, the rest metal goes to spokes.2) In the final deformation, metal flows to the boarder and the rim of the wheel andbridge ring has completed. With the going-down of the up die, the metal goes back to thecavity to finalize the fulfilling the rim.3. With the help of the FEA simulation and experiment, this paper analyses theforging process of AZ80Mg alloy wheel, and confirm the proper process parameters,which includes: forming temp.380℃-400℃; working speed6-10mm/s; COF0.2; whenthe designed fillet radius of the window in the bottom die is bigger than15mm, the Mgalloy formed part can be done in a6000T press machine.4. Metallographic Experiment shows that:In spoke metallographic structure, crystal grains’ size is bigger in the horizontal andvertical direction. crystal grains of tiny size exist and reveal in equiaxed. In the rimmetallographic structure, the tiny equiaxed crystal grained and increased in number; thecrystal grain are refined through pressing, crushing, stretching, and dynamicrecrystallization in the forging deformation.