Synergy Of Formability Of AZ31B Ultra-thin Magnesium Foil Stripby Asynchronous Electro-rolling Mechanism Research

Compared with the traditional magnesium alloy processing technology,the combination of asynchronous rolling and electroplastic rolling can not only significantly weaken the texture of the structure,improve the deformation energy storage,reduce the critical shear stress of the non-basal slip system and promote the occurrence of recrystallization,but also improve its mechanical properties and surface quality,especially for metals that are difficult to deform.Based on the micro deformation mechanism in the rolling process and the shape coordination ability of the rolled sheet,this paper explores a process method for the forming of magnesium alloy asynchronous strip electro-rolled foil.Firstly,the influence of different rolling methods on the shape synergy mechanism of magnesium alloy during strip rolling was investigated.By comparing the average Schmid factor of each slip system in the rolling deformation zone of synchronous electric rolling and asynchronous electric rolling(with different diameter ratios of 1.15 and 1.20respectively),the ability of magnesium alloy slip system to participate in plastic deformation under different rolling methods was analyzed.The results show that the asynchronous electric rolling with the diameter ratio of 1.15 makes the non-basal slip system more fully resolved and participates in plastic deformation.The tensile strength of the rolled plate is 12%and 10%higher than that of the other two methods,and the number of edge cracks and the maximum edge crack depth are significantly reduced.Secondly,the influence of different effective current densities on the shape-property synergy mechanism of magnesium alloy during tension asynchronous electric rolling with different diameter ratio of 1.15 was investigated.By comparing the average Schmid factor of each slip system in the rolling deformation zone under different effective current densities,the ability of slip system of magnesium alloy to participate in plastic deformation under different effective current densities is analyzed.The results show that when the effective current density is 27.9A/mm~2,the non-basal slip system is more fully opened and participates in plastic deformation.The tensile strength and elongation of the rolled sheet are higher than those of the other two current densities 24%and-3.2%,4.83%and 4.7%respectively,and the inhibition effect on the number of edge cracks and the maximum edge crack depth is the most obvious.Finally,based on the rolling method and current parameters selected in the above experiments,the multi-pass asynchronous electric rolling process of magnesium alloy was explored,and the feasibility of continuous asynchronous electric rolling was proved.Because the non-basal slip system in the deformation zone is fully involved in the slip during rolling,the magnesium alloy with a hexagonal crystal structure can have five independent slip systems involved in plastic deformation per pass.Finally,multi-pass asynchronous electric rolling without intermediate annealing was realized,and 0.077mm magnesium alloy foil was successfully prepared.As a new rolling process,strip tension asynchronous electric continuous rolling has the characteristics of on-line annealing and high production efficiency.The rolling of AZ31B magnesium foil has been successfully realized.It provides an important reference for the industrial production of extremely thin magnesium foil.