Study On Finite Element Simulation Of Superplastic Gas Bulging For Fine-Grained Magnesium Alloys Sheets

Magnesium alloy is one of the lightest of those alloys used as the basis of constructional materials. Its specific weight is small, and only two thirds of the aluminum alloy, one thirds of the titanium alloy. It is excellent in strength/density ratio, rigidity/density ratio and dimensional stability. And magnesium alloy is characterized by electromagnetic shielding, transcalent and recyclable. Magnesium is widely used in the fields of aerospace, automotive, communication and electronic industry. So, Study on the forming of magnesium alloys, forming of simulation technology have important practical significance and economic value on the realization of magnesium alloy processing and the practical use of industrialization.However, magnesium alloys generally exhibit poor workability because of hexagonal close packed (HCP) structure. It is difficult to fabricate hollow shell magnesium alloys parts by conventional plastic forming. Therefore, there will be more practical significance on its practical application to the expansion of the scope of a more complex shape of magnesium alloy parts, whether or not it has superplasticity study under certain conditions using superplastic bulging forming.In this paper, the magnesium alloy hemisphere pieces, the box-shaped pieces and a ladder-shaped pieces of superplastic forming process was simulated by using finite element analysis software Marc. Optimization of the superplastic forming process of magnesium alloy hemisphere pieces, the box-shaped pieces and the ladder-forming process parameters. Analysis of the thickness distribution and strain rate distribution of the hemisphere, the box-shaped pieces and the ladder-shaped pieces in the superplastic forming in different regions at different stages were done. The impact of the mold structure, coefficient of friction, strain rate sensitivity index, forming pressure on magnesium alloy of the box-shaped pieces and the ladder-shaped pieces of superplastic forming was identified which laid a solid foundation for the study of the magnesium alloy superplastic bulging experiment.The numerical simulation studies help to determine the magnesium alloy sheet superplastic bulging forming process at reasonable parameters. And through the contrast with hemispherical part of the simulation and experiment validate the accuracy of the simulation, so the simulation can be the further guidance to the experiment.