Study On Extrusion Technology Of Magnesium Alloy Wheel

With the scarcity of natural resources and increasingly stringent environmental protection requirements, lightweight is being the vehicle industry's development trend. Magnesium alloy parts have been widely used on the vehicle because magnesium alloy have rich resources, light-weight and good mechanical properties. At present aluminum alloy wheel has been widely applied on the car, rather than it magnesium alloys are more advantages: it can reduce the quality and fuel consumption, in addition it has high elastic modulus and good shock absorption, when used as a wheel is more suitable for rugged road. The wheel requires higher capability, because it plays the role of bearing the loads and transfers power. At room temperature the ductility of magnesium alloy is poor, and difficult for plastic forming, die casting is easy to produce the shrinkage, looses structure and other defects,these defects reduce the mechanical properties of parts, and result in the limit of magnesium alloy's application in the wheel.This paper puts forward the extrusion and bulging technology. The organizational structure of magnesium alloy was improved and magnesium alloy's mechanical properties were enhanced through plastic deformation, and replace the aluminum alloy used in car's wheel. First, hot compression test of as-cast magnesium alloy AZ80A was achieved, the influences on flow stress of temperature, strain rate have been studied. The flow stress model was building according to the data obtained from the magnesium alloy hot compression test. Using the material model, the different extrusion technology process of magnesium alloy wheel was simulated by DEFORM-3D software. Analyze the metal flowing law and verify the feasibility of the extrusion technology. At last the forming technology was optimized based on simulation results.The extrusion mould and bulging mould was designed and maked, the extrusion and bulging test was carried on. Obtained processing parameter : extrusion temperature was preheated at 380~410℃, the metal flowing law 0.15 mm·s-1(extrusion speed was calculated by deformation degree), bulging temperature was at 200~250℃. By the experiment, magnesium alloy wheel was formed. Mechanical properties with the different parts of wheel product are detected , the results showed that: the maximum tensile strength of wheel are much better than as-cast sample ,and meet the operating requirements of wheel.