Effect Of Heat Treatment On The Microstructure And Mechanical Properties Of 6082 Aluminium Alloy Control Arm

High quality,low cost and no pollution will be auto market competition ability and the core of the enterprise economic benefit with the development of science and technology.It plays an important role that the rational use of materials,especially the important parts of automobile materials and give full the potential of the heat treatment technology.Auto control arm is the key components that pass the force to the body in particular the wheel track,its quality is closely related to the personal safety of users,the requirement of stiffness,strength and service life is very high.The parts of bar materails directly machined and casted have poor mechanical properties and can't meet the using demand of control arm,so it is mainly producted by forging technology.But often appears the insufficient strength or plastic problem in production due to the complicated shape of parts,formed difficultly and aluminum alloy forming characteristics,which is a common problems currently faced by domestic producers.In this paper,the high temperature plastic deformation behavior of 6082 forged alloy control arm was firstly studied.Analysis flow stress behavior characteristics and microstructure of alloy materials within a certain amount of deformation temperature and deformation rate,research the influence factors of the thermal deformation performance in order to provide a theoretical basis for the heat process of extrusion,roll and forge.Then the influence of solid solution and aging treatment on the microstructure and mechanical properties of the alloy was discussed,which provided the basis for the continuous improvement of the comprehensive performance of the control arm.High temperature compression experiments has been done by compression testing machine with self-made control temperature box.Then the true stress-strain curve of 6082 forged aluminum alloy was got,stress-strain constitutive equation and flow stress constitutive equation of the alloy were established,and the material constants of the alloy during high temperature deformation were calculated.The influences of deformation temperature and strain rate on the microstructure of the alloy during high temperature deformation was examined by optical microscope,the results show that the main softening mechanism of the 6082 forged aluminum alloy is dynamic recovery during high temperature plastic deformation and the grain size increases with the decrease of the deformation temperature and the increase of the deformation rate.The effects of different solution and aging process parameters on the microstructure of the alloy was reseach by field emission scanning electron microscopy(FESEM),and the precipitated phase composition of solid solution and aging were detected by XRD parameters was tested with compression test machine.The results shows that alloy mainly contains ?(Al),cicular and spherical Mg2 Si phase,rod AlFe(Mn)Si phase after solution and age treatment.The size,number and distribution of AlFe(Mn)Si precipitated phase does not change with the heat treatment and time in the process of heat treatment,its main function for mechanical properties is Mg2 Si,the optimum heat process parameters of 6082 forged aluminum alloy control arm is that solution temperature is 555?,solution time is 2 h,stranded time in the air is 5s,aging temperature is 170?,the aging time is 8h.