Analysis Of Forging Process And Preform Shape Design For Aircraft Main Supporting Joint Part

The preform design is one of the most important parts of forging process.Applying reasonable preform design can not only optimize the order of filling inside the cavity,but also enhance the uniformity of forming and microstructure distribution,which are beneficial for controlling and improving the quality of forgings.In this dissertation,the equipotential field method combining with response surface method was used to optimize aircraft main supporting joint part with the aluminum alloy,and the result is satisfying.The main contributions of this work are as following:(1)Based on the finite element simulation technology and the physical and chemical test results of the billet and forging,the traditional forging process of aircraft main supporting joint part was studied and the effect of blocking process and one-heat forming on the quality of product was discussed.It reveals that cross upsetting with rolling process can achieve fine and uniformed microstructure,which ensures the microstructure property and mechanical property.One-heating process will lead inhomogeneous deformation which further cause the inhomogeneous microstructure and non-uniform mechanical property.Thus,a preform process was proposed to optimize the deformation and microstructure uniformity.Subsequently,the quality of product was controlled and improved efficiently.(2)The equipotential field method was applied into the preform design of aircraft main supporting joint part forging.According to the electrostatic field simulation analysis,the electric field distribution between the forging and the billet was obtained and the distribution regularity of electric potential surface was analyzed.As a result,the reasonable potential range for the bullet was determined.(3)The multi-objective optimization for the preform process of aircraft main supporting joint part forging was designed based on response surface method.The response surface prediction model was constructed by setting the electric potential value and volume ratio of pre-forging and final forging as variables and the filling rate and deformation uniformity as response objectives.The variable range design values were optimized and applied into finite element simulation.Finally,the optimal design for pre-forging was determined.