The Research Of High Polymer Powder Deep Drawing Forming On T2 Copper Micro Cup-shaped Parts

With the rapid development and application of micro-electromechanical systems and micro-mechanical systems, the demand for the micro parts become more and more high. The miniaturized parts greatly increased the difficulty of making manufacturing production and processing. In order to produce the acceptable quality of micro parts in high efficiency and stable production, we need to work out a new manufacturing method. The traditional plastic forming method played a huge role in micro parts production which developed the method of micro deep drawing, micro bending and micro extrusion. Flexible die forming process uses a flexible pressure-carrying medium to replace a rigid punch or die. Because of no needing die or punch in the forming process which will greatly reduce the mold manufacturing costs and improve production efficiency. At the same it does not contact with the rigid tool, so the parts formed have high accuracy and good surface quality.This dissertation proposes a new process method for fabricating micro parts based on the advantages of the flexible die forming. That is the high polymer powder deep drawing forming. This method has no special requirements on the gap of the traditional sheet metal forming. One die can be fabricated micro parts with different length of the blank, significantly reduce the mold manufacturing cost. Meanwhile, the parts formed by the process have high forming limit, good forming quality and high surface qualityIn order to obtain the true stress-strain curve, using the four thickness of 0.4mm, 0.2mm, 0.1mm and 0.05 mm of T2 copper conducted tensile test Using three different polymer powders polyvinyl chloride(PVC), ultra-high molecular weight polyethylene(UHMW-PE) and ethylene vinyl acetate copolymer(EVA) do the compressions test to get the stress-strain curve. ABAQUS software is used to simulate the entire deep drawing process. The results showed that the uses of PVC powder forming the cup-shaped parts are basically consistent with the experimental results. Designing and machining different molds in the experiment. Using polyvinyl chloride, ultra-high molecular weight polyethylene and ethylene vinyl acetate copolymer powder as pressure transmission medium to carry out the experiment. Finally found PVC powder has the best effect on forming the cup-shaped parts. And the amount of powder has effect on the whole experiment. With a thickness of 0.4mm, 0.2mm, 0.1mm and 0.05 mm of T2 copper as experimental material, polyvinyl chloride powder as a pressure transmission medium to carry out deep drawing experiment. Drawing ratio is the ratio of the diameter of the blank to the diameter of the cup-shaped part; it ranged from 1.8 to 2.2. through the experimental results found that when the blank thickness are 0.4mm, 0.2mm and 0.1mm, the forming effect is very good, the maximum drawing ratio can reach 2.2. When the blank thickness down to 0.05 mm, the cup can be basically forming but the yield is not very high. The thickness analysis of the cup-shaped parts found that the cup-shaped parts formed by the PVC powder medium thinning is less than the cup-shaped parts by the rigid tool when compared in the same bottom corner.