Hydroforming Process Of LY16 Aluminum Alloy For Thin-walled Parabolic Curved Surface Part

In order to improve the thrust-weight ratio of airplane engine,a large number of components must be designed and manufactured with lightweight materials.Based on this situation,aluminum alloy materials are widely used in aviation engines.For the low plasticity and poor formability of aluminum alloy materials,especially for some complex surface and thin-walled parts,it's difficult to adopt traditional forming method and avoid wrinkles and ruptures due to the existence of large suspension area of sheet.Hydro-mechanical deep drawing process is a relatively advanced forming technology for complex surfaces,which can be used to improve the forming limit of sheet metal parts.The LY16 aluminum parabolic surface part of an aircraft engine fairing was studied as the research object,and the mechanical properties and forming limit were carried out on the LY16 aluminum alloy.In this research,two kinds of process schemes were put forward,including two steps of hydroforming procedure and three steps of hydroforming procedures.The method of numerical simulation was adopted for the two kinds of schemes to simulate the forming process.By using this method,it can be found that the three steps of hydroforming process scheme can satisfy the forming need.In this paper,the finite element numerical simulation is used to study the forming process.The influence of tool clearance of the first step and the loading path of the liquid in chamber were studied on the thickness distribution and the forming quality of the specimen.The influence of the liquid loading path of the second step was studied on the wall thickness of the specimen.The influence of the initial liquid chamber pressure was studied on the thickness of the specimen wall and the forming quality.The proper tool clearance,liquid pressure,and initial liquid pressure in chamber were decided for getting a better shape.The simulation results show that the defects can be avoided and the thickness of the wall is more evenly distributed.Three steps hydroforming die sets were established and were carried out for the deep drawing process.The blank-holder gap,liquid pressure in chamber and the loading paths were discussed on the forming quality and wall thickness distribution,Wrinkling and cracking defects of deep drawing process were analyzed in the hydroforming process.The correctness and accuracy of the numerical simulation result was verified,the reasonable process parameters and forming specimen were obtained by experimental works.