Study On Thin Aluminum Fins Forming And Opimization

As an important part of the heat exchangers,the fins’ shape and area mainly determine the efficiency of the air-conditioning.With the continuous progress of energy saving and automotive lightweight processes,the development of thinner fins is pressing.However,due to the reduced thickness of the aluminum foil,the cracking in the flange hole is prone to appear in the multi-position progressive die stamping process,what seriously impact the processing efficiency and product quality.Based on the forming limit diagram(FLD)experiment,finite element modeling and response surface method,this paper took the 8011-H22 l aluminum fins for an example to study on forming aluminum fins and process optimization.The work done consists following aspects: 1)FLD experiment for the aluminum foilsTraditional FLD experiment method requires the specimen to mark grid in aluminum foils by electrical erosion.However,due to the thickness of aluminum foil is too thin,the electrical corrosion will impact the FLD results.In this paper,no damage UV printing technology was applied to marking grid in specimens,and successfully launched a FLD experiment for 0.11 mm 8011-H22 aluminum foils.Then based on the "Strain Acceleration" failure criteria,a complete FLD was obtained by the finite element simulation of FLD experiment,what laid a theoretical foundation for the analysis and optimization of the aluminum fins forming process.2)the simulation and analysis of aluminum fins formingThe finite element model of forming aluminum flange hole by the multi-position progressive die stamping was built.The deformation and reduction in each forming process were analyzed,and the comparison between the FEA results and the actual production verified the accuracy of the model.Based on that,the factors on forming results,including thickness of aluminum foil,punch stroke settings,friction between sheet metal and molds and die spacing,were discussed and summarized.3)the optimum design on the process of forming aluminum finsBased on response surface method(RSM),the multi-response model between the punch stroke of 5 drawing steps and the reduction of foils was established to analyze the interaction between the different steps by conducting a Box-Behnken DOE.And on this basis,the response surface method is optimized to get optimal combination of stroke settings by desirability function approach.The FEA results show: the forming quality of flange holes after optimizing was significantly improved compared to that before optimizing,which reached the expected goal.