| Magnesium is the lightest structural metallic materials, magnesium alloy not only has high specific strength and specific stiffness, but also has good thermal performance, electromagnetic shielding and mechanical processing properties of shock absorption, and the product easy to be recycled. Determine the characteristics of magnesium alloys in the automotive, electronics, aerospace and other fields widely used. Therefore, magnesium alloy box-type parts of the shaping law, the practical processing of magnesium alloys and industrialization have important practical significance. However, magnesium alloy sheet at room temperature ductility is poor. Only magnesium alloy heated to a certain temperature, deformation in the thermoplastic state, the hardening process of constantly being back, and then offset by the crystallization process. Magnesium alloy sheet at this time in a low strength and high plastic softening state, this state can achieve good formability.Based on the above theory AZ31B magnesium alloy box-shaped parts (rectangular and curved) deep drawing process of thermal numerical simulation. Finite element analysis software Dynaform, Deep drawing process of AZ31B magnesium alloy was simulated. rectangular and curved parts of magnesium alloy and forming the thickness distribution has been analyzed, the results found that the punch corner and the corner punch area is too deep drawing of magnesium alloy Cheng Zhongcheng largest regional force and deformation, and the straight edge punch fillet and the straight edge corner parts of the punch the punch than the circular edge of the corner fillet and punch a bigger regional force and deformation of this area is the drawing sheet of the most vulnerable to rupture defect area. Summarized by stamping simulation speed and friction coefficient on the impact of deep drawing process to determine the friction coefficient and drawing speed. BHF is a very important process parameters in deep drawing, this paper presents incremental step type and valley type of variable blank holder force curve load simulation program. Incremental step of the type of variable blank holder force BHF role of small moments and small to large BHF BHF buffer time into the change of the impact of deep drawing, analysis of changes in peak and valley type of blank holder force moment of peak conversion changes on the impact of deep drawing.results in the formation and quality are more than under constant blank holder force obtained deep drawing box-type parts.This chapter first carried out the design drawing die, designed heated blank holder, using heating rods so that the blank holder reaches a certain temperature, the heating rod end series of temperature control devices, and digital temperature control by heating temperature setting to achieve setting and control. Hot Drawing achieve the purpose. Obtained in the simulation of the 2 types of variable blank holder force curve after loading optimal curve, the corresponding variable blank holder force system and its structural design. |
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