Theory Research On Continuous Extrusion Extending Deformation Process Of Copper Bus Bar

Comparing with traditional manufacturing technique, continuous extrusion technology for copper bus bar has many excellences, such as high productivity, low energy consumption, no contamination, no restriction in product length and high quality, so it is widely used in production.Copper bus bar continuous extrusion deformation process far is very complex, and the billet endures fierce 3D plastic deformation and shearing deformation. Friction condition and temperature rising rate of material, deformation temperature and deformation resistance, the state of metal under force and deformation manner, etc. determine the deformation process. If the technique parameters and the die structure are not chosen correctly, many defects will be caused, for instance curling, cracking and lacking material of the products, and the dies will be also spoiled easily.The paper strives to analyze the parameters of force and energy of continuous extrusion process by theory calculation and finds the relationships between extrusion force, energy consumption, deformation temperature and the parameters of die chamber; and forecasts the defects existing in the extrusion process by FVM numerical simulation soft ware MSC. Superforge, to adjust technique parameters and put forward ameliorate projects.The main job of this thesis including the following four parts:1. Combining continuous extrusion technology with forming technical characteristics, the necessity, feasibility and superiority to simulate the continuous extrusion extending deformation process for copper bus bar with FVM are expatiated.2. By reasonably simplifying the geometry model of copper bus bar continuous extrusion and the division of forming zone, the parameters of force and energy were analyzed. According to the transform principle of heat-work combined with test, the formulas of forming force and energy consumption concerning deformation temperature in each sub zone are deduced; by programming calculation, analyized the effects of friction, product width and thickness and billet diameter on extrusion force; gained the energy consumption and temperature in every deformation sub zone; investigated the pressure acted on billet by coining roll and the deformation pressure endured by stationary abutment.3. According to the plastic deformation characteristics of copper bus bar, FVM and analytic method were used to analyze the large and complicated deformation process, and basic theory of elastic-plastic material FVM was introduced.4. The simulation results are analyzed detailedly. By analysizing contact pressure distribution of billet surface and the metal flow velocity field, the chamber design is optimized and the forming process of copper bus bar is improved with the simulation results. The conclusions of the paper could provide theory basis for the forming of large demension copper bus bar, the optimization of die chamber and the design of large model extrusion machine.