Numerical Simulation And Experimental Research On Near-net Forging Formation Of 2A12 Hard Aluminum Alloy Conical Shell

The high-performance and high-strength aluminum alloy conical shell is one of the key structural parts of a certain projectile,and its forming effect plays a decisive role in the overall performance of the projectile.At present,high-strength aluminum alloy conical shell parts are facing the difficulty of precision forming and good performance.The 2A12 duralumin alloy conical shell part studied in this project includes two parts,an arc-shaped cone and a thin-walled shell,which play an important role in bearing,connecting and sealing on the elastic body,It is a part that needs to be mass-produced.There are some engineering problems such as low production efficiency,serious waste of materials and poor performance of machined parts by using traditional machining method.With the increasing demand of the weapon and ammunition industry for the forming quality and performance of the parts,the machining method of mechanical chip is no longer suitable for the production of the parts.Near-net forging technology refers to the forging technology which can be used as mechanical components after a small amount of processing or no processing to reach or close to the shape and size of the finished parts.It is "new process+new material+new equipment+new technology" "Comprehensive integration technology.As a precision forging forming method,precision hot die forging can achieve near net forming of 2A12 high-strength aluminum alloy parts.Through the numerical simulation of the precision hot die forging forming process of the conical shell parts and the experimental research on the forming process,a feasible and reliable near-net forging forming process plan is obtained,which can guide the actual production of the conical shell parts and similar parts Sexual meaning.In this paper,the precision hot die forging process of 2A12 duralumin conical shell used for projectile body was studied by means of finite element numerical simulation,forging process test,metal streamline analysis,micro structure observation and microhardness test.The main work and conclusions are as follows:(1)According to the structural characteristics and dimensions of the 2A12 hard aluminum alloy conical shell parts,the forming process analysis,process plan design,and numerical simulation test are carried out.The results show that the optimized scheme of ?50 mm bar band saw cutting?hot forward extrusion?hot composite extrusion?hot reverse extrusion preforming ? hot upsetting extrusion can effectively prevent the occurrence of defects such as fold,destruction,flash.At the same time,the forming load required by the optimized scheme is low,the service life of the die is increased,and the forming quality of the conical shell forging is excellent.(2)According to the forming process plan,die design and manufacturing,and forging process tests are carried out.The results show that the forging process test is carried out according to the optimized scheme,and the taper shell forgings with full metal filling and main dimensions meeting the design requirements are successfully produced.In the process test of precision hot forging forming of the conical shell,the maximum forming force required by each process is close to the forming force obtained by the numerical simulation test.(3)Through the metal streamline analysis,metallographic microscopic analysis and microhardness test of the formed forgings.The analyses shows that the conical shell forgings have good metal streamlines,high structure density,and the average increase in hardness reaches 39.5%.Therefore,the use of precision hot die forging can obtain 2A12 duralumin alloy cones with excellent mechanical properties.Shaped shell forgings.(4)Comparative analysis shows that the use of precision hot die forging method to process the conical shell parts,the utilization rate of the material reached 85.8%,and the nearly net forging forming of the 2A12 hard aluminum alloy conical shell parts is realized.For the mechanical chip processing method,the material utilization rate has increased by 52.3%,and the production efficiency has increased by 25 times.