CAD,CAE Of Large-size Explosive Pressing Die Under Superpressure

Large-size explosive pressing dies are used in the process of explosive powder compaction. It bears the peculiarities of large size, high employed pressure, eimited materials, which are adopted ultra-high tensile steel (σs≥ 1400Mpa) usually. The selection of materials is discussed in this paper. Some special design techniques with the help of CAD are presented in this paper. Moreover, the stress distribution and variation resulted from the external conditions in mould are analyzed by the method of finite element (FM) to meet the requirements of strength and rigidity. Also, the Kinematics simulation is studied, which used to analyze the movement interfering among mould components and in case of scratching.As the backbone of the making of die, the selection of materials has a great effect on the quality and life of die. The status of development and application of die materials are presented in this paper at the present time and, the studied are emphasized on the ultimate strength as well as impact toughness of several types of high strength steel with high performance. By the comparing the comprehensive properties, i.e., the metallurgic properties, heat processing, attributes for mechanical processing etc., three types of high strength steel, 300M,C300 and D6AC are locked for the key materials in pressure die.As the operating pressure of pressure die could reach the value of 200Mpa, the die concerned here are belonged to extra-high pressure vessel. Based on the design strength theory of powder metallurgic die and extra-high pressure vessel, the strength of key component, i.e., die sleeve, is computed theoretically and the results are contrasted with each other. The computed results shows that the mono-sleeve structure bears much more thick wall and much more weight ,which may cause many difficulties in forging, heat processing and nondestructiveexamination. So, the double-sleeve structure design of interfered fit are determined and shrink fit procedure are adopted.To meet the requirement of pressure process, the structure of die are determined preliminarily based on the theoretically computing. By the help of CAD technique, the model are constructed by the method of parameterization. The finite element code, i.e., ANSYS, is employed to simulate the active state of the die and it show that the design model has a good agreement with the theoretical computing results. As for some unsuitable components in the analysis, the size parameters are optimized.