Research On The Micro-mechanism Of Single Point Progressive Forming Plastic Deformation Of Magnesium Alloy Sheet

Magnesium alloy was the most obvious feature is qualitative light,environmental protection green metal structure material,its specific strong,the specific mode of the application of lightweight,high strength plate has gradually become a highlight of material industry at home and abroad,has increasingly become the focus of industrial competition.With the application of single point progressive forming technology in sheet metal plastic forming,it is gradually applied to magnesium alloy forming.However,the current study is limited to simple basic experimental studies,mostly on light alloy material such as magnesium alloy shape on the macroscopic,the research of magnesium alloy material shape of the technological process and forming quality.In order to really make forming process not only can "forming",also can realize the "integrity",in order to make the forming parts at the same time meet the requirements of dimensional accuracy and performance,analyze from the microscopic view.In this paper,the finite element software ANSYS/Is-dyna,the numerical simulation on the single point incremental forming of magnesium alloy,analysis the technological parameters of temperature,tool radius and feed on magnesium alloy plate in incremental forming stress the influence regularities of the variation of the stress,the thinning rate,and based on the results of numerical simulation of incremental forming to carry out the relevant experimental study.At the same time using the Marc software simulation analysis and microscopic experiment analysis,microstructure change of single point incremental forming of magnesium alloy simulation analysis research,analysis of the microstructure of magnesium alloy under different parameters change,explore the microscopic mechanism of single point incremental forming of magnesium alloy plastic deformation rule,to develop reasonable forming process and determine the parameters of the optimal value to improve the quality of forming parts and provide theory basis for precision.The results show that the forming temperature,the size of the tool head and the feed amount have obvious influence on the micromechanical mechanism of the single point of magnesium alloy.The forming temperature has significant effects on the formability of magnesium alloy sheet,with temperature rise,plate grain increased,under the condition of forming temperature is 250 C,sheet showed good plastic formability,dynamic recrystallization occurs obviously enhanced;When the tool head radius is within the range of 5-8mm,the thickness of the forming parts varies uniformly,the thickness of the wall thickness is small,the average grain size has a large trend,and the grain size is relatively uniform when the radius is 5mm.Feed on forming a reduction ratio and grain size,feeding in 0.2?1.0 mm,the maximum shear stress and the maximum reduction ratio gradually increasing trend along with the increase of feed,gently incremental reduction ratio,with the increase of the feed,the average grain size increases,feeding is 0.7 mm,plate shape,reduction ratio,degree of grain refinement is best.The comparison of AZ31 magnesium alloy and 6061 aluminum alloy shows that the grain of magnesium alloy is smaller than that of aluminum alloy.When the temperature is 200??350?,the grain size of magnesium alloy is relatively large.The influence of the radius and feed amount of the tool on the aluminum alloy was relatively large.