Research On The Superplasticity Of Aluminium Alloy 5083

Railbound vehicle's lightweight requests to use the light alloy. However, The light alloy is generally difficulty to precisely form components due to its lower plasticity at room temperature. Superplastic forming is one of the best methods to precisely manufacture light alloy components.Through experiment of unidirectional tensile at high temperature, the flow stress and elongation of the 5083 anti-rust aluminum alloy sheet is studied with changing temperature and strain rate. The results show that the flow stress of the alloy reduced with increasing deform temperature and increased with increasing strain rate and the elongation reduced with increasing strain rate. The higher the temperature, the more significant of the decreasing tendency that the elongation corresponding to the reducing of strain rate.The Arrhenius equation incorporating the effects of stress, strain rate and temperature of the material is derived. A revised Arrhenius equation is derived by compensation of strain and strain rate. Comparisons between the experimental and predicted results were carried out and confirmed that the developed constitutive equations can accurate response the experimental result in a certain temperature range and the majority of regional flow stress.For most materials, cavitation often precedes failure and excessive cavitation can impose significant limitations on the industrial usage of superplastically formed components. The volume fraction of AA5083 is tested separately in unidirectional tensile and bulging. The effect of hydrostatic pressure on cavitation is studied through exerts back pressure. It is found that hydrostatic pressure has significant inhibition on cavitation and can reduce the cavitation density massively.To simulate superplastic forming of AA5083, a commercial non-linear FE code MSC.Marc has been used. Compared with experimental result, good uniformity is achieved.