Large Width-to-thickness Ratio Copper Bar Continuous Extrusion The Physical Analog Production Practices

The copper conductive bus bar be playing an important role in the industrial power transmission. The traditional production processes of copper bus bar were the extrusion, rolling or extrusion-rollingusion. However, the traditional processes were multi-process, with expensive equipment. The traditional production processes almost be replaced by Continuous Extrusion technology, because of these technical advantages of Continuous Extrusion as energy saving, high efficiency, short process and near net shape, equipment inexpensive, good performance of production, etc. But the productions made by Continuous Extrusion were defect as cleft edge, color, uneven lateral grain size, and thickness of the size difference because the uneven metal flow in the process of large expansion, for the copper bus bar were produced by large width-to-thickness and large cross-section by Continuous Extrusion.Currently, the maximum size of the copper bus bar produced by TJ550type CONFORM equipment was204.5mm X15mm,and the expansion ratio was9.30,the width-thickness ratio was13.6. In this thesis, for204.5mmX7.5mm copper bus bar research, the die structure was studied by the Physical Model and field trial combining for the copper bus bar with large width to thickness ratio and large cross-section by CONFORM. The plasticine was used be model material in the physical modeling, the plexiglasses was be made to the tooling die by the ratio1:1.The die structure initially identified according to the law of plasticine flow in the plexiglasses, the actually die was designed and manufacturing for the field experiment by TJ550type CONFORM equipment. The die was be made appropriate correction according to the field trial.The law of die designed was got by these research for the copper bus bar with large width-to-thickness ratio and large cross-section by CONFORM equipment, include the structural parameters of dumbbell-shaped, the changes of bearing lengths width,baffles height and baffles angle along the width direction of the product. Three kinds of extrusion die with high expansion ratio and width-to-thickness ratio have been designed according the rules proposed above. Field trial was carried out by using a TJ550type CONFORM equipment producing copper bus bar with a specification of204.5mm×7.5mm, of which the expansion ratio reaches9.30, and width-to-thickness ratio reaches27.27Results of trial production shows the defect of edge crack has been eliminated, and the inhomogeneity of surface color and transverse thickness of product has been decreased.Finally, there is a forecast about the use of conform technology in the production of large overall for copper\aluminum siding profiles in this thesis.