钨丝／Zr基金属玻璃复合材料的界面反应与扩散

The Interface Reaction and Diffusion of Tungsten-Fiber/Zr-Based Bulk Metallic-Glass Matrix Composites

摘要:

采用渗流铸造工艺制备了钨丝增强不同Nb含量的Zr基金属玻璃复合材料，利用X-Ray衍射、扫描电镜以及电子探针考察了复合材料界面反应和界面扩散情况，研究了基体合金中的Nb含量对复合材料界面反应和界面扩散的影响。结果表明：对Zr55Al10Ni5Cu30基复合材料，渗流时，钨丝与液相中的Zr发生界面包晶反应，生成W5Zr3界面相，并使界面位置向液相方向移动。在Zr55Al10Ni5Cu30合金的基础上添加Nb，发现Nb优先在钨丝界面偏聚，降低了Zr在钨丝界面的偏聚和活度，抑制钨丝与液相中的Zr包晶反应的发生，没有生成W5Zr3界面相，界面处只存在简单的扩散层。同时发现Zr元素在钨丝中的扩散系数降低，此时界面位置向钨丝方向移动。

Abstract:

Zr-based metallic-glass matrix composites, which were reinforced by continuous tungsten fibers, were prepared by melinfiltration casting. The interface reaction and diffusion were analyzed by using X-Ray diffraction, SEM and EPMA. The influence of Nbcontent of the matrix alloy on the interface reaction and diffusion was also investigated. The results illustrate that for the Zr55Al10Ni5Cu3matrix composites an interface eutectoid reaction between W fiber and Zr in the liquid phase takes place and a W5Zr3 phase is formed athe interface. The interface moves to the direction of the liquid phase. For the matrix alloy containing Nb, the addition of Nb in the liquidcauses a significant change of interface reaction. Nb in the liquid phase exhibits a preferential adsorption at the surface of the W fiber, thusreduces the adsorption of Zr atom in the liquid phase at the surface of the W fiber. The activity of absorbed Zr at interface is decreasedand depresses the interface eutectoid reaction between W fiber and liquid. In this case the interface is a simple diffusion layer only. At thesame time the diffusion coefficient of Zr in the W is decreased by Nb addition and the interface moves to the direction of W fiber.