Research On Formability And Forming Limit Of Aluminum Alloy Sheet In As-Quenched State

Aluminum alloy has a series of advantages such as low density,high specific strength,strong corrosion resistance,easy to conduct heat and conductivity,good plasticity and processability,low cost and so on.It is the main structural material of the aviation industry.The as-quenched aluminum alloy is the intermediate state of heat treatment.The mechanical performance parameters and forming performance index for the reference of production are not all of the query in various manuals and standards.The specific parameters under different aging time are lacking.But the parameters which vary with the aging time will directly affect the quality of forming parts.Therefore,it is of great value to study the forming properties and forming limit of the aluminum alloy sheet in as-quenched state.In this paper,the 6061 and 7075 aluminum alloy sheet as the object of study.Aimed at the three aging time points which were the most concerned in the factory production: 20 min,40min,60 min,the test plan was designed.The mechanical properties of these two kinds of aluminum alloy sheets in different aging time were obtained by carrying out the uniaxial tensile test.And the influence of aging time on these parameters was summarized.The finite element simulation for FLD of the aluminum alloy sheet in as-quenched state under different aging time were carried out by using DYNAFORM finite element analysis software and combining the performance data from the uniaxial tensile test.The FLD for finite element prediction of two kinds of aluminum alloy sheet under different aging time were obtained.Using the M-K instability theory and combining with the Hosford yield criterion,the FLD of aluminum alloy sheet under different aging time was deduced by theoretical derivation.The FLD for theoretical prediction of two kinds of aluminum alloy sheet under different aging time were obtained.Finally,the forming limit verification test was carried out.The FLD of the two plates under the test conditions were obtained.The results were compared and analysed with those of the finite element simulation and theoretical deduction.The feasibility of finite element analysis and theoretical prediction was verified.The influence of the aging time on the forming properties and forming limit of sheet metal was summarized,which provided guidance and reference for the actual production of aviation industry.