Effect Of Microstructure Characteristics And Size Effect On Mechanical Properties Of Industrial Pure Aluminum Sheet

With the increasing demand of energy density of lithium batteries,the thickness of aluminum sheet for has been reduced to less than 10?m,and its electrical conductivity and tensile strength are required to be higher and higher.In this paper,industrial pure aluminum sheet of lithium batteries is taken as the research object.And this paper analyzed the effects of the main alloying elements Fe,Si content and Fe/Si ratio on its conductivity and strength,in order to explore the optimum composition control range of the content of Fe/Si and analysis the influence of"size effect"on material properties.It is found that with the increase of impurity elements?Fe+Si?,the conductivity of aluminum sheet decreases sharply,and the tensile strength increases.With the same content of total Si/Fe,the conductivity of the sample increases gradually with the decrease of Si/Fe ratio,and the tensile strength of the material decreases accordingly.When Si/Fe is small,the number of the second phase is large,and most of the second phase compounds are Al₁₂Fe₃Si phase,which is hexagonal system.However,when Si/Fe is large,the number of the second phase in the structure of aluminum plate decreases obviously,and the main second phase compound is Al₉Fe₂Si₂ of monoclinic system.The damage rate of solid solution strengthening on electrical conductivity is obviously higher than that of work hardening on electrical conductivity.When the thickness of the material reaches grain size categories,the effect of size effect on the properties of the material becomes more significant:with the decrease of thickness,the elongation of the material decreases gradually,and the tensile strength decreases significantly.The trend of yield strength/elongation,deformation and stress distribution inside and outside of the grain can be simulated by using finite element software Abaqus and its compiled subroutine.The experimental results show that the yield strength and elongation of the material will increase with the increase of the thickness of the model,the yield strength and elongation of the material will also increase with the decrease of the grain size in the model,and the different grain orientations have great influence on the yield strength and elongation of the material.