Dynamic Properties And Analysis Of Adiabatic Shearing Localization Of Tungsten Alloy Matrix Material

Tungsten alloy is a kind of material composed by the tungsten grain and the matrix material; it becomes the main material of long rod projectiles because of its excellent properties such as its high density, high strength and good toughness and so on. Tungsten grain is one material that has high strength and body-centered cubic structure, and it distributes in the matrix that is soft and has the surface-centered cubic structure. Most of the tungsten grain dissolved into the matrix when the tungsten alloy is sintered. In this paper the matrix material of tungsten alloy used in tests contains Ni and Fe and Ni to Fe is 8 to 2 and the tungsten is about 25 percent. In this paper, we combine experiments with theories. Dynamic compressing experiment has been performed for the matrix material of the tungsten alloy in order to study its dynamic properties. At the same time we have studied the forming process of adiabatic shear band of tungsten alloy and its matrix material.In this paper, the dynamic compressing experiments for the matrix material of the tungsten alloys which have been three different deforming(0%, 32.6%, 44.6%) processed have been performed by the experimental technology of separated Hopkinson pressure bar and many accurate datum have been obtained. Also the three materials have been compared with each other and analyzed. The results show that the optimized values are in a certain range to optimize the materials by changing their deforming technology. The parameters of constitutive model of Johnson-Cook have been fitted based on the datum. Then proceed to the next step, adiabatic shear band of these three matrix materials has been analyzed with finite element method. The result shows that the relations between stress and strain are different because of the differences of technical process of the three materials, but they are in great commonness in the material experiment and in great coherence in the distribution of time and space, which can been seen from the space distributing figures of plastic strain.In this paper, the adiabatic shear band in tungsten alloy material has been analyzed with finite element method, and also the influence of thermodynamics parameter on shear-localized of tungsten alloy has been analyzed. The constitutional model of Bodner-Partom no-yield surface has been adopted, which makes calculation of numerical value more convenient. Finally, the forming and localization course of shear band of tungsten alloy material have been analyzed. The influence of thermodynamics parameter of density, static yield stress, specific heat coefficient and heat conducted coefficient on shear-localized of tungsten alloy has been contrastively and individually analyzed through changing magnitude of each parameter. The result has shown that static yield stress and specific heat coefficient have bigger influence on the shear-localized of tungsten alloy.