Mechanical Properties And Bending Performance Of Magnesium/Aluminum Sheet

Magnesium alloy often exhibit the obvious tension-compression asymmetry during the plastic deformation in room temperature.Because magnesium alloy(hcp structure)sheet can only provide limited slip system at room temperature.Besides,the outward migration of neutral layer in magnesium alloy during the bending forming is due to different deformation mechanism in the inner and outer layer.The Mg/Al composite plate has a wide application prospect.Because it combined the magnesium alloy and aluminum alloy property,such as low density,high strength and excellent ability of plastic deformation.Consequently,we adopt the composite extrusion to the preparation of Mg/Al composite sheet.Firstly,we observe the interface in the Mg/Al composite plate by XRD and EDS for the sake of recognize the interface combination degree and the diffusion layer thickness.Secondly,we use the metallographic analysis,XRD,electron back scattering diffraction technology(EBSD)to explore the microstructural evolution in the process of extrusion.In addition,base on the early stage of the design plate compression mould and three-point v-shape bending die,we apply the mechanical properties(tensile and compression)tests to explore the relationship between the neutral layer of offset and the mechanical properties for composite sheet metal.Ultimately,the research content can be summed up in two aspects:1.Comparison the tension-compression asymmetry and bending behaviors of composite extruded plate which includes AZ31,AZ31/AZ31,AZ31/Al three different sheets.2.Study on the effect of sheet-set condition and component layer thickness on the mechanical property and bending behavior for Magnesium/Aluminum extruded sheet.The component layer thickness include AZ31(2.5mm)Al(0.5mm);AZ31(1.5mm)Al(1.5mm);AZ31(0.5mm)Al(2.5mm).Final results are as follows:1.It can be found that the combination between intermediate diffusion layer and magnesium,aluminium alloy layer is well(no obvious gap)and intermediate diffusion layer thickness is relatively appropriate,about 3.6 um in the observation of diffusion layer in Mg/Al composite sheet.2.When AZ31/AZ31 sheet compared with AZ31 sheet,although both of them displayed failure behaviors in the process of bending,the load of AZ31/AZ31 is obviously lower than AZ31 plate.As for the Al/AZ31 composite sheet,it display the best bend behavior and without failure behaviors from starting to end.3.The tension-compression asymmetry performance presents a declined trend with the increase of Al content in Mg/Al composite sheet.In addition,the sheet-set condition and component layer thickness have a strong impact on the mechanical property and bending behavior(include the shift of the strain neutral layer)for Magnesium/Aluminum extruded sheet,the bending load-displacement curve is the intuitive evidence.It worth to noting that the Mg(2.5mm)Al(0.5mm)composite sheet is fracture in both two sheet-set condition(Alin/Mgout or Mgin/Alout)and the crack initiation in the surface of magnesium layer,while others Mg/Al composite plates exhibit the better bending forming.