Research On Forming Mechanism And Key Technologies Of Hybrid Impact Hydroforming

In aerospace and automobile industry fields, the demand of structural lightweight is increasingly urgent, so complex structure parts of special material is becoming more and more widely applied. For some large components with small size feature, it is hard to use hydroforming to form these components completely, and it is especially hard to assure the shape and strength of the small size feature at the same time. Impact hydroforming is an advanced manufacturing technology that uses liquid shock wave converted from the release of high-energy liquid to achieve parts’elastic-plastic forming, and it can provide high pressure at a short time to form components, so the forming velocity is apparently higher than traditional hydroforming. Meanwhile, the forming process will lead to high strain rate, and the formability of some materials sensitive to strain rate will be changed, especially to the lightweight alloy material with poor plasticity, so the applied range of these material in national defense is broadened. Therefore, the study on impact hydroforming is very meaningful.In this paper, the principle and characteristics of impact hydroforming was introduced first, and the key problems of mechanism under impact hydroforming were discussed. It involves the dynamic problem and the material model selection the process. In terms of the research on the impact hydroforming equipment, the paper mainly focuses on the design of the energy source structure in the impact hydroforming equipment and the structure optimization. Two sets of impact hydroforming test tooling have been designed to meet the needs of the impact test.Meanwhile basic on the principle of ellipse expansion, the drawing method of the diagram of sheet forming limit under impact hydroforming has been presented. The tube impact forming test has been done, basic on the tube forming tooling.Finite element model of the whole process was established in the finite element software ABAQUS/Explicit. Using fluid solid coupling technique to simulate the impact energy and the whole process of sheet metal forming, the simulation mold is truly enough after comparing the simulation results and the experiment. Two different radium of the channel was compared by using the simulation mold.