Study On The Modal Analysis And Casting-extrusion Compound Forming Technology Of Magnesium Alloy Wheel

Wheels are main load-bearing and high-speed rotating components.It is very important significance for saving energy and reduction emission, using magnesium alloy to manufacture wheels with light weight. The design methods for magnesium alloy wheel are in the state of half experience and half theory,and are not reliable criteria for wheels designs.Casting is main forming technology for magnesium alloy wheels.and the casting properities is poor.It is difficult to guarantee the performance uniformity and stability by casting.The mechnical properities of forged magnesium alloy are perfect for wheels. But because of bad deformation ability,it is difficulty for forging.There are need many processes for wheels foging and the forming efficiency is low. It also is difficulty to reduce the costs. So, the new design methold and forming technology are need urgently for magnesium alloy wheels.Aiming at the deficiency design method、low peroperities of casting spoke、bad peroperities of uniformity and reliablty of casting technology and low efficiency and many processes of forging technology for magnesium alloy wheel forming. the present study researched on the modal analysis and casting-extrusion compound forming technology for magnesium alloy wheels.On the base of results of the forming verification testingand and properities testing,studied the new design methold and forming Principle and technology.for magnesium alloy wheels.Firstly, the results of the dynamic/static characteristics studing of magnesium alloy wheels using numerical simulation technology are references foe materials selection and the structures optimization. The basies of reduction strength and equivalent static toughness were used for mateiral selection. The AZ91D magnisium alloy was selected as wheels manufacturing material. Optimized the structure of wheel by using design criteria by using modal analysis and equivalent static toughness matching. The results of materials and structure parameters are reference for magnesium alloy wheels forming by casting-extrusion technology.Secondly, based on dynamic material model, this trail-manufacture experiment established a two-demensional processing map of AZ91D magnesium alloy using the thermal and force simulation experiment. The processing map are the reference for parameters selection. Studied the process of dynamic recrystallizatin during compression and established the dynamic recrystallization critical stress model of AZ91D. Studied the forming microstructures and mechanical properties response by plane strain compression tests. Providing the reference for microstructures and microstructures and mechanical properties controlling for magnesium components.Thirdly, the rule of defects formation of AZ91D was studied during process of low pressure casting by numerical simulation technology.The results of optimized parameters of low pressure casting model and process were the reference for dies dedsigning and forming process parameters selection. Using deformation homogeneity factor as evaluation index, studied effect on the deformation uniformity by deformation temperature、deformation velocity、deformation amount and structure factor. The model of relationship between deformation homogeneity factor an deformation temperature、deformation velocity、 deformation amount and structure factor was extablished. Providing the reference for billet structure desiging and deformation uniformity controlling for magnesium alloy components forming.The prent put forward method of lacation plastic deformation to improve the properties of the casting components for using, enhancing production efficiency and material utilization, reducing the production costs.The structure of magnesium alloy wheel was optimized using design criteria of modal analysisand matching equivalent static toughness. Compared with the traditional semi-empirical and emi-theory design methold, the prent methold is more scientific and reasonable. Established the model of relationship between deformation homogeneity factor an deformation temperature、deformation velocity、deformation amount and structure factor. Using the model, the billet strcture design became moe scientific.The magnesium alloy components forming became easier to be controlled. The formed structure mechanical properities uniformity and stability can be guaranteed. Put forward csting-extrusion compound technology for magnesium ally wheels,solved the problem of traditional forming process, improved the production efficiency, reduced the manufacturing cost of magnesium alloy wheels.At last, Designed the forming devices and studied the verification test for AZ91D magnesium alloy wheelusingcasting-extrusion compound thchnology.the properities of formed wheelare welland laid the foundation for engineering applications for magnesium alloy wheel using casting-extrusion compound forming technology.