Abstract: 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 andα-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 0.2~5 μm. The volume fraction of in-situ particles and the melt temperature are both enhanced with the increasing of initial reactive temperature. The ag.gregation and growth of Al3Zr particles occur when the melt temperature is higher than 1 200 ℃. It was proposed that the chemical reaction between zirconiu.m oxychloride (ZrOCl2) and liquid aluminum is a complex process including both. gas-liquid reaction and solid-liquid reaction. The kinetic model and the velo.city of chemical reaction for ZrO2/Al reaction, which is the key step in ZrOCl.2-Al reactive system, were established.
Reactive mechanism of Al3Zr (p) , Al2O3 (p) /Al composites formed by reaction between ZrOCl2 and liquid aluminum
Abstract:
The microstructures of Al 3Zr (p) , Al 2O 3 (p) /Al composites formed by reaction in melt from ZrOCl 2 Al system were examined by X ray diffraction (XRD) and scanning electron microscope (SEM) . The results indicated that Al 3Zr and α Al 2O 3 particulate phases are produced by the reaction between ZrOCl 2 and liquid aluminum. The size of Al 3Zr and Al 2O 3 particles with a polyhedral shape is in the range of 0.2~5?μm. 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 Al 3Zr particles occur when the melt temperature is higher than 1?200?℃. It was proposed that the chemical reaction between zirconium oxychloride (ZrOCl 2) 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 ZrO 2/Al reaction, which is the key step in ZrOCl 2 Al reactive system, were established. [