超低W-W连接度W-Cu-Zn新型合金的制备及动态力学性能研究

钨铜合金由于其高密度、高硬度和良好的耐热性能，在兵器领域拥有极高的应用潜力，但是常规方法制备的钨铜合金动态屈服强度较低，动态延伸率极差，严重制约了钨铜合金在兵器战斗部领域的应用。针对上述问题，申请人在本课题前期工作中深入研究了钨铜合金组织结构与力学性能的关系，发现W-W连接度是影响钨铜合金动态延伸率的关键因素，而铜基体相的强度是制约钨铜合金动态强度的关键因素。本课题旨在采用钨粉化学镀铜与SPS放电等离子烧结相结合的方法制备具有超低W-W连接度的W-Cu-Zn系新型钨合金，通过降低合金中W-W连接度，避免动拉伸载荷作用下W-W界面分离引起材料失效，以此提高合金动态延伸率；在粘结相中添加Zn元素，利用Cu-Zn析出相的强化作用提高合金的动态屈服强度。拟深入开展合金制备工艺、W-W连接度控制工艺、析出相调控机理和材料动态力学性能等方面的研究，为军用新型钨合金的研发和工程应用奠定理论和实验基础。

Due to the high density, high hardness and excellent thermal resistance, W-Cu alloy has great potential applications in warhead materials. However, the W-Cu alloy prepared by routine methods usually exhibit relatively low dynamic yielding strength and very poor ductility under tensile loading, which severely restricted the applications of W-Cu alloy in military field. In previous study, we made in-depth analysis on relationship between microstructure feature and mechanical properties of W-Cu alloy and found that,the W-W contiguity is the key factor for the dynamic ductility of W-Cu alloy, and the strength of Cu matrix is the key factor for the dynamic yielding strength of W-Cu alloy.In the present study,a new method base on combination of electroless Cu plating on the surfaces of tungsten powders and spark plasma sintering (SPS) methods is proposed to prepare the W-Cu-Zn alloy. The W-W contiguity of W-Cu-Zn alloy is controlled at a very low ratio, so as to enhance the ductility of W-Cu-Zn alloy under dynamic tensile loading,and element Zn added in the matrix can form precipitation phase with Cu, which is used to increase the dynamic yielding strength of W-Cu-Zn alloy. On this base of ultra-low W-W contiguity and addition of Zn, the preparation techniques of W-Cu-Zn alloy,the control method of W-W connected degree, the precipitation theory of Cu-Zn intermetallic compound in matrix and the dyanmic mechanical behaviours are systematically investigated. The results will provide theory and experimental base for the development of new tungsten heavy alloy and its applications on key military materials.