Investigations On Precision Forming Technology And Manufacture Of Aviation Large Die Forgings

The manufacturing level of large die-forging is a vital driving force for the development of national aviation industry,and is also a manifestation of national manufacturing capabilities.In the United States,Russia,France and other developed countries,the manufacturing technology of the overall aviation die forgings is regarded as the core secret of national security.The 800 MN large die forging press that was completed in 2013 is strategic equipment related to national security and economic development.It is also the basic equipment for the aviation industry,especially the “big aircraft project”,which provides conditions for the manufacture of large aviation die forgings.Titanium alloy and 300 M steel large die forgings are very important for the development of large national aircraft.In the previous research,the microstructure and plastic forming of titanium alloy and 300 M steel were generally studied as two independent directions and obtained a certain degree.The effect of this type of research neglects the coupling relationship between the deformation behavior of the material during the actual deformation process and the microstructure evolution,which has certain limitations.In this paper,two typical die forgings of TA15 titanium alloy long beam forgings and 300 M high-strength steel landing gear forgings are used as research objects,and advanced thermal simulation and other physical testing methods are used to thermally process large-scale aviation components with titanium,high-strength steel and other materials.The properties of the material were studied under high temperature conditions,and the real stress and strain data of the materials required for the large forgings were obtained.Based on these data,the constitutive model of the TA15 and 300 M alloys was constructed,and the dynamic model was applied to the crystallization.In the finite element simulation of large-scale aviation forgings,the microstructure evolution of large forgings during hot forming is predicted.By combining the relationship between the microstructure and the macroscopic properties of the materials,the preform and forging processes are successfully optimized.Finally,through the development of typical test pieces,the key technologies of breakthrough have been further applied and promoted,and a complete set of die forging technology has been formed,which provides guarantee for the development of national key aircraft models and is crucial for the development of national aviation industry.