The incongruent reactions between Zr-Cu melts and WC solid were studied. Mo was used as a tracer to track the movement of “heavy” W atoms during the incongruent reaction. In separate experiments, dense polycrystalline plates and porous preforms of W0.9Mo0.1C were reacted with Zr2Cu and Zr14Cu51 melts at 1200 °C, 1300 °C and 1600 °C for 15 minutes. The microstructure of the reactive interfaces was studied using scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The change of microstructure and chemical composition at the reactive interface was observed as a function of temperature, Zr content in the melt and radius of the W0.9Mo0.1C solid. When the Zr-Cu melts contact the W0.9Mo0.1C solid, W, Mo and C all dissolve in the melt. The precipitation of W and W2Zr is based on Zr activity in the Zr-Cu melt after a quick formation of ZrCx. Both the dissolution rate and the amount of WC solid increase with decreasing radius of the WC particles, increasing Zr content in the Zr-Cu melts, and increasing reaction temperature. If the dissolution rate of WC is fast enough and the WC particles are in small sizes, the dissolution-precipitation is the main aspect. If a continuous ZrC layer quickly forms to separate the WC solid from Zr-Cu melts. The reaction is, therefore, controlled by the diffusion of carbon through the W and/or ZrC layers.

中文翻译：

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Zr-Cu熔体与固态碳化钨不协调反应的机理

研究了 Zr-Cu 熔体和 WC 固体之间的不一致反应。在不一致的反应过程中，Mo 被用作追踪“重”W 原子运动的示踪剂。在单独的实验中，W0.9Mo0.1C 的致密多晶板和多孔预制件与 Zr2Cu 和 Zr14Cu51 熔体在 1200 °C、1300 °C 和 1600 °C 下反应 15 分钟。使用扫描电子显微镜、透射电子显微镜和能量色散 X 射线光谱研究了反应界面的微观结构。观察到反应界面处微观结构和化学成分的变化是温度、熔体中 Zr 含量和 W0.9Mo0.1C 固体半径的函数。当 Zr-Cu 熔体接触 W0.9Mo0.1C 固体时，W、Mo 和 C 都溶解在熔体中。W 和 W2Zr 的沉淀基于 Zr-Cu 熔体中 ZrCx 快速形成后的 Zr 活性。随着WC颗粒半径的减小、Zr-Cu熔体中Zr含量的增加以及反应温度的升高，溶解速率和WC固体量均增加。如果WC的溶解速度足够快且WC颗粒尺寸小，则溶解-沉淀是主要方面。如果快速形成连续的 ZrC 层以将 WC 固体与 Zr-Cu 熔体分离。因此，该反应受碳通过 W 和/或 ZrC 层的扩散控制。如果WC的溶解速度足够快且WC颗粒尺寸小，则溶解-沉淀是主要方面。如果快速形成连续的 ZrC 层以将 WC 固体与 Zr-Cu 熔体分离。因此，该反应受碳通过 W 和/或 ZrC 层的扩散控制。如果WC的溶解速度足够快且WC颗粒尺寸小，则溶解-沉淀是主要方面。如果快速形成连续的 ZrC 层以将 WC 固体与 Zr-Cu 熔体分离。因此，该反应受碳通过 W 和/或 ZrC 层的扩散控制。