Research On Dimensional Accuracy Of 5A03 Aluminum Alloy Prepared By Single-Point Incremental Hot Forming

With the continuous updates and iterations of technology,there has been a growing demand for high-performance,lightweight,small-batch,and diversified products.Singlepoint incremental forming has attracted attention due to its advantages such as simple forming tools,no need for special die,low cost,and high flexibility.However,at room temperature,the plastic deformation ability of difficult-to-process aluminum alloy sheet metal is poor,and when using incremental forming technology to form target parts,it is often prone to problems such as severe local thinning of parts,low dimensional accuracy,and even inability to form.Currently,more and more scholars are focusing on the hot incremental forming of sheet metal and have verified that heating can effectively improve the forming quality of target parts,but geometric accuracy of the parts remains an important issue that restricts its development.This paper is based on 5A03 aluminum alloy and explores the influence of different forming strategies and process parameters on the dimensional accuracy of single-point incremental hot forming parts.Firstly,uniaxial tensile tests were conducted on 5A03 aluminum alloy at different temperatures and strain rates.Through macroscopic and microscopic analysis of the 5A03 aluminum alloy after thermal stretching,it was determined that the mechanical properties of the sheet were relatively better at 250℃.Additionally,taking into account the influence of temperature and strain rate,a constitutive equation for high-temperature tensile behavior of 5A03 aluminum alloy was constructed based on the modified Misiolek model.Furthermore,a finite element model for single-point incremental forming of 5A03 aluminum alloy was established using ABAQUS simulation software.An experimental setup for electrically assisted single-point incremental forming was also constructed.An evaluation method for dimensional accuracy of the formed parts was determined.Through experimental analysis under the same set of process parameters,the accuracy of the finite element analysis results for single-point incremental forming of 5A03 aluminum alloy was verified,with a relative error of less than 10% between simulation and experiment.This indicates that the established finite element model for single-point incremental forming of 5A03 aluminum alloy sheet can accurately reflect the material’s deformation characteristics.Moreover,the influence of forming tool motion strategy on the dimensional accuracy of the target part cross-sectional profile was investigated using ABAQUS simulation software.Analysis of the simulation results showed that when the forming tool motion trajectory and direction were set to dispersed downward points,with the first and third passes formed clockwise from top to bottom,and the second pass formed counterclockwise from bottom to top,the dimensional accuracy of the target part crosssectional profile was relatively better.Single-factor experimental results showed that as the forming tool-head diameter and step-down increased,the dimensional accuracy of the target part cross-sectional profile first improved and then deteriorated.As the feed rate increased,the dimensional accuracy of the target part cross-sectional profile gradually deteriorated,but the magnitude of the deterioration was small.Finally,the interaction effects of different process parameters on the dimensional accuracy of the target part cross-sectional profile were investigated using the BoxBehnken response surface method.Based on the fitted multivariate quadratic response surface regression equation,the best set of process parameters for dimensional accuracy of the target part’s section profile was obtained as follows: The tool-head diameter was12 mm,the step-down was 1 mm,and the feed speed was 650 mm/min.The profile information of the formed parts was collected using a 3D scanner,and the relative error between the predicted accuracy value of the model and the actual accuracy value was less than 10%,further verifying the accuracy of the optimization results.