Research On Stable Rolling And Near-net Shape Forming Methods Of Super-large Profile Aluminum Alloy Ring For Aerospace

Super large profile aluminum alloy rings have important applications in Aerospace Launch equipment,such as the transition ring of launch vehicle fuel storage tank.These rings have the characteristics of super large size and special profile,which are difficult to form.In addition,the deformation temperature range of aluminum alloy materials is narrow,and the rolling process is more complex than steel parts.At present,for super large profile aluminum alloy rings,the ring rolling process is mainly used to form rectangular section forgings,and then a large number of cutting processes are used to obtain the special profile.This manufacturing method not only has low material utilization and processing efficiency,but also destroys the integrity of metal streamline and weakens the mechanical properties.Near net rolling forming is an important development trend of high-performance manufacturing of this kind of rings.However,the near net rolling process of super large profile aluminum alloy rings has large size changes,complex profile and low strength of aluminum alloy materials,which makes it difficult to control the stability of the rolling process and to form the special profile.Therefore,this paper studies the stable rolling conditions and near net rolling forming methods of super large profile aluminum alloy rings.In view of the difficulty in controlling the stability of super large profile aluminum alloy ring in the rolling process,this thesis first reveals the influence law of guide mechanism parameters on ring rolling stability by means of finite element simulation,and puts forward the optimal range of guide mechanism parameters to ensure the motion stability in the ring rolling process;In order to prevent the plastic instability of the ring caused by excessive guiding force in the rolling process,this paper puts forward the rigid stability mathematical model of the super large profile aluminum alloy rings through theoretical analysis,and obtains the rolling instability criterion of the super large profile aluminum alloy rings.The validity of the model is verified by finite element simulation and physical experiment.The theoretical model provides a theoretical basis for the control of guiding force in the stable rolling process of super large profile aluminum alloy rings.In view of the difficulty in forming the near net special profile of super large profile aluminum alloy rings,this thesis reveals the evolution law of geometric dimension parameters of super large special profile aluminum alloy ring in the rolling process by means of finite element simulation and theoretical analysis,and puts forward the theoretical model of geometric evolution of super large profile aluminum alloy ring and the optimization design method of ring blank.Based on the above research results,combined with the thermal deformation characteristics of aluminum alloy materials,the ring parameters and stable rolling guiding force after each ring billet heating in the rolling process are designed.Through finite element simulation,the near net rolling process of super large profile aluminum alloy ring is simulated and analyzed,the variation laws of ring temperature field,strain field and rolling force under this technical scheme are revealed,and the feasibility of near net rolling forming of super large profile aluminum alloy ring is explained.Through the above research,this subject has established the stable rolling conditions and near net rolling forming methods of super large profile aluminum alloy rings.The research results enrich the rolling theory of super large profile aluminum alloy rings,and can provide theoretical and technical support for the high-performance manufacturing of super large profile aluminum alloy rings for aerospace carrier equipment in China.