Research On High Temperature Flow Behavior Of Squeeze Casting 6082 Aluminum Alloy

As a typical 6000 series aluminum alloy,6082 aluminum alloy is widely used in aeronautical and automobile industry as structural parts due to its high specific strength,good machinability and excellent forging performance.These parts are usually produced by forging,but for complex parts,forging will have more processes,which increases the cost of the mold,reduces production efficiency and utilization rate.Besides,during the forging process,abnormal growth of recrystallization occurs during heat treatment.In this paper,6082 aluminum alloy is used as the research material.A method that the forging stock fabricated by squeeze casting is forged only once has proposed to provide an effective production plan for the production of steering knuckle control arm.This method also provides a certain reference and guidance for actual production.The effect of squeeze casting parameters on the microstructure of 6082 aluminum alloy was studied.The high-temperature unidirectional compression experiments of 6082aluminum alloys fabricated by different squeeze casting pressures were performed.By analyzing the true stress-strain curves at a temperature of 350?-500? and a strain rate of 0.01 s^-1-10 s^-1,the flow behavior at high temperature was analyzed and the effect of squeeze casting pressures on flow behavior was explained.The results show that the 6082aluminum alloys fabricated at a higher squeeze casting pressure exhibit higher flow stress.When the compression conditions are the same and the strain rate is not too much high,the gap of the flow stress caused by the different squeeze casting pressures decreases with deformation temperature increasing.Finally,the constitutive equations were established for the forging simulation.Based on the high temperature compression experiment,the corresponding processing maps were constructed.By studying the microstructure evolution during deformation,the relationship among the microstructure,the processing maps and squeeze casting pressures were systematically explained.The processing parameters were optimized and microstructures can be well predicted.Thereby reliability of processing maps was verified.The results show that as the temperature increasing or as the strain rate decreasing,the softening mechanism of the 6082 aluminum alloy gradually changes from dynamic recovery to dynamic recrystallization,the 6082 aluminum alloys fabricated under high squeeze casting pressure are more likely to occur dynamic recrystallization and the grain size is smaller.High temperature can weaken this phenomenon.When the squeeze casting pressure is in the range of 50-100 MPa,the optimum processing parameters are proposed within the temperatures ranging from 430?-500? and at strain rates of 0.1s^-1-1 s^-1.Taking the steering knuckle control arm as the research object,the structural characteristics are analyzed,and the data of the research are used to design the squeeze casting and forging route.The forging process was simulated in Deform-3D,and the feasibility of the process parameters and the route were verified.