Study On Microscopic Performance Of Radial Forging Body And Finite Element Simulation Of Crystal Plasticity

The development of modern war has higher requirements for the performance of the barrel which is the main mechanical part of automatic weapons objectively. Barrel radial forging is a process of plastic forming in which the preferred orientation of the metallic materials grain will form texture. On the macro perspective, the existence of texture is the aeolotropism of the material which has an impact on the reliability and longevity of the barrel.This article was started from the micro structure analysis of the barrel and did X ray diffraction experiments on the material of the barrel. Through the analysis of the diffraction patterns, the important information such as the crystal system, symmetry and space group were ensured. Applied the information we had got from the analysis of the diffraction patterns into the Multex which is a texture analyzing software to process and calculate the incomplete pole figure and achieved the pole figures of material deformation and the figure orientation distribution functions. Using the principle of crystallography to analyze the orientation distribution function diagram, we got the information of the textures of the barrels. Through combining texture analysis results and the law of Schmid and analyzing the slipping of the slip systems in the three directions of the grains under the reflection of different textures to discuss the deformation mechanism and the anisotropy mechanical properties of the body centered cubic metal.Conclusion could be draw from micro level analysis that the forged barrel the yield strength in the direction of the tangential stress and radial stress are weaker than the axial direction and later will explain it.On the basis of the theory of crystal plasticity finite element, the crystal plasticity constitutive relation of the material was imported into the crystal plasticity finite element model by the User-defined material mechanical behavior of ABAQUS. The polycrystalline geometric model was built by the Voronoi algorithm in Matlab. The polycrystalline finite element model in the process of the barrel forging was established according to the geometric parameters of the barrel and the process parameters in the process of forging. With the grain orientation information gotten from the simulation, the pole figure was made in the Matlab. Compared with the pole figure of the experiment, the rationality of the polycrystalline finite element model was verified.Apply this model into extraction and analysis of the changes happened during the process in which the grain orientations of the CPFEM model were forged by hammers with different forging press angle. Through the pole diagram the condition of the material textures and the change of the grain orientations were analyzed. With the pole figures, the influences of the hammer forging press angle on the material deformation were discussed.