【作者】 刘筱玲；

【导师】 陈虬； 宋顺成；

【作者基本信息】 西南交通大学 ， 固体力学， 2003， 硕士

【摘要】 钨合金的高强度、高密度、良好的塑性等特征使高比重钨合金在兵器工业中成了现代穿甲弹弹芯的主要材料。进一步提高弹芯材料的强度和韧性，发展高强韧钨合金成为兵器工业的重要课题。本文主要通过对钨合金宏细观力学性能的测试与计算，研究了钨合金材料变形强化后的细观结构参量与静态宏观力学性能之间的关系。 对钨合金性能的测试主要内容包括宏观力学性能及细观各相及界面的力学性能的测试，并且利用人工神经网络BP算法对实验所得数据进行了处理及预测。预测结果表明，利用人工神经网络BP算法预测不同细观参量下钨合金的宏观力学性能是可行的。 本文利用Eshelby等效夹杂的概念和Mori-Tanaka平均应力概念，由钨颗粒相的形状、组分和两相力学参数给出了钨合金宏观屈服强度和抗拉变形行为的分析计算。计算结果基本上反映了不同变形量工艺处理的钨合金材料的细观量与宏观量的关系。 利用有限元方法对单向拉伸载荷作用下，不同变形量的93W合金进行了数值模拟计算，从钨合金的有限元计算可知，随着变形量的增加，钨颗粒长细比增大，颗粒极区的应力水平将会影响钨合金的性能，也即变形量的无限增大，并不能无限提高合金的性能，反而对合金性能有害。对于变形量较小的钨合金，首先在基体相中达到屈服，此时钨合金材料的屈服强度决定于基体相的屈服强度：而对于变形量较大的钨合金，钨颗粒中应力水平增加较快，将首先在钨颗粒相中达到屈服，此时钨合金材料的屈服强度决定于钨颗粒相的屈服强度。更多还原

【Abstract】 In this paper, relations between the macro mechanical properties of the tungsten heavy alloy (WHA) and its micro structural characteristics were presented.It was tested that young’s modulus, static yield strength and tensile strength of WHA and mechanical parameters of each phase including in the matrix phase and the tungsten phase, the W-W boundaries and W-matrix boundaries, and with the SEM, the micro structural of fracture was observed. The data of tests was dealt with BP Neural Networks and its results showed that BP Neural Networks was feasible to predict the trend of tensile strength of WHA with the change of the different shapes and volume fractions of W-phase.The hardening modulus of the matrix in plastic deformations was measured with MTS, and the macro-tensile strength of the tungsten alloys treated by different super-deforming technology was analyzed by using Eshelby method and Mori-Tanaka concept of ’average stress’. The fracture of the tungsten grains was supposed to be brittle. The results of analysis were comparable with the results of tests. The calculation with the finite element method simulating the different shapes of W-phase of 93 WHA also showed the same conclusions.更多还原