Numerical Simulation Of Relative Density In Spinning And Assessment Method For Uniformity Of Powder Liner

As the most important energy source at present, petroleum has brought to the attention of the world, with the development of global industrialization. Then, shaped perforation technology, which is widely used in oil exploration and defense, has become a hotspot. As the key component of shaped charge, the processing quality of liner will have a direct impact on the jet. Powder Metallurgy Technology is the main processing method of liner, because of flexible composition and better. However, the liner would have the nonuniform defects of particle and porosity, if have inappropriate parameters of pressing process. These defects would make jet off-axis, and influence penetrating depth, even make jet breaking.In this paper, powder liner is studied. The finite element model for spinning process is established, and the influence of spinning parameters for relative density and powder flowability are simulated. The concept of areal density is proposed, and uniformity of areal density is detected. The main contents and results are as follows:(1) Continuum Finite Element Method of liner is established based on Metal Plasticity Mechanics, in the soft MSC.Marc. In this method, the influence of die friction, both in pressing and spinning, rotational speed of female die, and pressing force for relative density are simulated. The different influence for relative density between pressing and spinning are also simulated. The simulation results show that:relative density, both in pressing and spinning, decreasing with the increase of die friction, but the uniformity is improved; compaction is improved when add the rotation of female die; relative density increasing with the increase of rotational speed, but the uniformity decreased when the rotation of female increased; and the compaction effect is better when have larger pressing force.(2) Multi Particle Finite Element Model is also established in MSC.Marc. Powder flowability is simulated based on Multi Particle Finite Element Method. The results show that: powder has better flowability in spinning than in pressing, which means great significance for composite powder, and the flowability decreased with increase of friction coefficient.(3) In order to calculate the information of uniformity of areal density for powder liner, JSM-5600LV SEM is used to identify constituent, and MEF-3 metalloscope is used to record metallographic images, finally, Image-Pro-Plus is used to calculate after using MATLAB to denoise processing for metallographic images. The simulation results of axial porosity are verified the accuracy of the finite element model compared with experimental results and the error is only 4.97%. Finally, to improve the quality of liner, some suggests are given.In this paper, the influence of spinning parameters for relative density and powder flowability are revealed using numerical method, moreover, a assessment method for uniformity of Powder Liner is proposed, and it has important theoretical and practical significance for guiding production and improving processing quality for powder liner.