Investigation on Reaction Interface between the Aluminum and K2ZrF6 by Freezing the Molten Salt Reaction

A reaction interface between the aluminum and K2ZrF6 during molten salt reaction process was frozen by quenching the mold in water, and the interface structure was analyzed to determine the formation process of Al3Zr. Results show that a clear conical interface existed between the K2ZrF6 and aluminum. A zirconium accumulation layer with the thickness of about 2–3 μm was formed at the aluminum side of the interface. Many initially formed Al3Zr particles (with the size of 0.4–16 μm) distributed in this layer, most of which located at the interface. The morphology of Al3Zr particles is closely related with their size. For the size of 0.4–1 μm, the Al3Zr appeared as globular and ellipsoid shapes. When it grew to the size of 1–2 and 2–16 μm, it exhibited the rule cube shape, and rule cuboids shape, respectively.