高密度钨合金性能的计算机数值模拟研究──钨含量对合金性能的影响

摘要:

提出了一个钨合金的组织结构模型，在一定的假设条件下用有限元方法和计算机数值模拟研究了钨合金力学性能和钨含量的关系。结果表明；随钨含量增加，合金屈服强度提高，但弹性变形量和延伸率均降低。当钨含量＜85％（质量分数，下同）时，合金抗拉强度随钨含量增加而增加；当钨含量＞85％时，合金抗拉强度随钨含量增加而降低，在钨含量为85％附近达到最大值。在低钨含量合金中（＜90％），高应力主要集中在钨颗粒中，随钨含量增加，粘结相中应力水平降低；在高钨含量合金中钨颗粒和粘结相中应力水平基本相同，随钨含量增加，粘结相中应力水平

Abstract:

A microstructural model of heavy tungsten alloys is offered. On the basis of this model and several assumptions, the effects of tungsten content on micro-mechanical behavior and macro-mechanical properties of the heavy tungsten alloys under tensile deformation are analyzed using computer numerical simulation. The tungsten content is assumed to be within the range of 80 wt% to 95wt %. The results show that the yield strength of the heavy tungsten alloys increases with the tungsten content, while both the elastic deformation and the elongation decrease. The variation of tensile strength with tungsten content is not monotonic. For tungsten contents<85 wt%, the tensile strength increases with the increase of the tungsten content, while the tensile strength decreases strongly for tungsten contents >85 wt %. At a tungsten content of 85 wt %, the tensile strength is a maximum. This behavior is explained in terms of the stress distribution between the tungsten grains and the matrix phase. In the alloys with low tungsten content (<90wt % ), the high stress concentrates in tungsten grains. As the tungsten content increases, the stress in matrix phase decreases slightly. In the case of high tungsten content, however, the maximum stresses in tungsten grains and matrix phase are the same, and higher tungsten content results in higher stress in matrix phase.