Optimization Of Continuous Extrusion Forming Process Parameters Of AZ31 Magnesium Alloy

Magnesium alloy is the lightest metal material, which is known as green material of environmental and resources sustainable development in the twenty-first Century. However, the magnesium alloy is close packed six party crystal structure, its plastic deformation ability ispoor at room temperature, using the traditional processing method has a long process and a small amount of deformation, multiple heating is required and the rate of finished products is low. Continuous extrusion technology is the advantages of short flow, energy saving,environmental protection and high efficiency with the friction force as the driving force. Therefore, the continuous extrusion extending forming of magnesium alloy is researched with the numerical simulation method, forming process parameters of continuous extrusion are optimized, which has an important role in guiding to setting up the parameters of magnesium alloy in the continuous extrusion process.In this paper, in type 400 and type 500 continuous extrusion machine as the prototype, the continuous extrusion process of magnesium alloy is simulatedby using the DEFORM-3D software,, the influence of different process parameters on the forming law of expansion is discussesed, the following conclusions are got:(1) According to the orthogonal experiment,the two specifications magnesium alloy plate by the 400 type continuous extrusion forming are carried on the numerical simulation, the mean-square deviation of the velocity is calculated, The relatively optimal parameters were acquired:the optimal parameters of 80mm*8mm magnesium alloy plate forming;the optimal parameters of 120mm* 8mm magnesium alloy plate forming are the wheel speed5 r/min, tool and die preheating temperature 400℃, flow passage length 50 mm.(2)Basing on the results of two kinds of magnesium board in the orthogonal test, the test results were analyzed by the range analysis and the variance analysis, it was concluded that the parameters influence on extending forming flow uniformity order and significance, effect of extrusion wheel velocity is the most significant, the effect of flow passage length is second, the effect of tool and die preheating temperature is not obvious.(3)Influence of multi-parameters factors on continuous extrusion extending forming of magnesium alloy by orthogonal design is same with the single factor. the influenceregularity. With the increase of extrusion wheel velocity, the flow uniformity is worse,with the increase of flow passage length and mould preheating temperature,flow uniformity is better, while reaching a certain numerical,the flow uniformity reduces.(4)The simulation results of stress and strain field of the representative test is analysed in orthogonal scheme scheme. The results show that, in the expansion area along the thickness direction, the strain increases gradually from the upper to lower surface area; in the vertical, the maximum occurs in the edge of cavity entrance, the two peaks of stress appeared in the two dividing areas of dierespectively.(5)the parameters which significantly influence the flow uniformity, The influence regularity of the extrusion wheel velocity and flow passage length on the extending forming of 160mm* 8mm magnesium alloy sheet whit 500 continuous extrusion machine as the prototype. With the increase of extrusion wheel speed, the metal flow uniformity is better, the torque of the extrusion wheel reduces, the temperature of the blank and the cavity increases, the stress and strain value increases, recommendations on the selection of extrusion wheel speed is 6r/min; With the flow passage length increases, the metal flow uniformity increases first and then decreased, the blank and mould temperature increases, the torque of the extrusion wheel increases, recommendations on the selection of the flow passage length is 60mm.