ZrOCl_2-Al体系熔体反应生成Al_3Zr_((p)),Al_2O_(3(p))/Al复合材料的反应机制

利用X射线衍射仪 (XRD)和扫描电子显微镜 (SEM ) ,对ZrOCl2 Al体系熔体反应生成的复合材料组织进行了分析 ,结果表明 :ZrOCl2 Al体系反应生成相为Al3 Zr和α Al2 O3 ,颗粒尺寸为 0 .2～ 5 μm ,形状以多面体为主 ;随反应起始温度升高 ,生成的颗粒体积分数增大 ,熔体温度也升高 ,但当熔体温度高于 12 0 0℃时 ,Al3 Zr出现聚集、长大。提出了ZrOCl2 Al体系的反应是气液反应和固液反应的复合过程 ,建立了ZrOCl2 /Al反应中的控制环节ZrO2 /Al反应的动力学模型及化学反应速率的关系式。

Reactive mechanism of Al_3Zr_((p)), Al_2O_(3(p))/Al composites formed by reaction between ZrOCl_2 and liquid aluminum

The microstructures of Al3Zr(p), Al2O3(p)/Al composites formed by reaction in melt from ZrOCl2-Al system were examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicated that Al3Zr and α-Al2O3 particulate phases are produced by the reaction between ZrOCl2 and liquid aluminum. The size of Al3Zr and Al2O3 particles with a polyhedral shape is in the range of 0.2～5μm. The volume fraction of in-situ particles and the melt temperature are both enhanced with the increasing of initial reactive temperature. The aggregation and growth of Al3Zr particles occur when the melt temperature is higher than 1200℃. It was proposed that the chemical reaction between zirconium oxychloride (ZrOCl2) and liquid aluminum is a complex process including both gas-liquid reaction and solid-liquid reaction. The kinetic model and the velocity of chemical reaction for ZrO2/Al reaction, which is the key step in ZrOCl2-Al reactive system, were established.