Study On Forming Of Isothermal Extrusion For Drum Aluminum Alloy Shell

The drum Aluminum alloy shell is the big end of Torpedo which has complex shape,high precision size and high performance requirement. It has been manufacture by the way ofcasting processing with steel as raw materials. The old method is high energy consumption,high production cost, does not meet the energy saving requirement is not suitable for massproduction. Steel products can not meet the needs of future empennage service due to highweight. For these questions, this paper use of 7A04 aluminum alloy as raw materials ininstead of steel materials, which with lighter weight and higher strength, research foraluminum alloy shell isothermal extrusion forming process.This parts has special shape: in the center of the cylinder is a through-hole. The diameterof the top of the shell is smaller than the middle, and there is a straight part in the top.Research on this kind of special structure and complex parts for extrusion forming is verymeaningful.According to the characteristics of the structure of the parts, the forming process wasanalyzed and extrusion part drawing was determined. Use the 3D finite element numericalsimulation software DEFORM to establish the simplified model, analysis the simulationresults of forming the top of the shell and the straight part through the way of shrink mouth.The flow law of metal during isothermal extrusion was analyzed based on the establishmentof simplified model. The influence of different extrusion temperature and extrusion speed andfriction factors on the strain-effective and load of metal variation curve with simulation steps,which promotes the technological parameter reference for the aluminum alloy empennagecylinder forming. Combined with the simulation results and comprehensive other factors toconsider: under the condition of the extrusion temperature is about 480℃,the friction factor is 0.2,and the extrusion speed is 15mm/s for forming is more reasonable.On the basis of the research, the mould was designed and optimized, and theexperimental research was carried out. The result showed that: formulation process schemewas feasible, designed mould was appropriately applied, metal flow was uniform and theeconomic benefits was high,which laid the foundation for engineering applications of thesimilar parts.