Abstract: The interfacial structure of Al3Zr/Al and crystal morphology of Al3Zr particulates in Al3Zrp/Al composite formed by Al-K2ZrF6 reaction in the melt were studied by transmission electron microscopy (TEM). The results indicate that the crystal morphology of in-situ formed Al3Zr particulate is mainly polyhedron or rectangle. There are the facets on the surface of Al3Zr particles. The close packed plane of Al3Zr crystal with a tetragonal structure is (11ˉ4ˉ).The interface between Al3Zr particulate and aluminum matrix, where there is no reaction product, is smooth and clean. According to the analysis of electron diffraction pattern and the atomic arrangement at the Al3Zr/Al interface, there is a crystallographic orientation relationship of [2ˉ2ˉ1]Al3Zr∥[100]Al and (012)Al3Zr∥(11ˉ0)Al.Therefore, it may be concluded that aluminum can nucleate on Al3Zr particles with a small lattice mismatch 10.87%. Moreover, Al3Zrp/Al composites fabricated by direct melt reaction have not only well-distributed solidification microstructure but also excellent mechanical properties.
Interfacial structure of Al3Zrp/Al composites formed by Al-K2ZrF6 reaction system
Abstract:
The interfacial structure of Al 3Zr/Al and crystal morphology of Al 3Zr particulates in Al 3Zr p/Al composite formed by Al-K 2ZrF 6 reaction in the melt were studied by transmission electron microscopy (TEM) . The results indicate that the crystal morphology of in-situ formed Al 3Zr particulate is mainly polyhedron or rectangle. There are the facets on the surface of Al 3Zr particles. The close packed plane of Al 3Zr crystal with a tetragonal structure is (1 1- 4-) .The interface between Al 3Zr particulate and aluminum matrix, where there is no reaction product, is smooth and clean. According to the analysis of electron diffraction pattern and the atomic arrangement at the Al 3Zr/Al interface, there is a crystallographic orientation relationship of [2[DD (-*2/5]- 2- 1] Al 3Zr ∥ Al 3Zr ∥ Al and (0 1 2) Al 3Zr ∥ (1 1- 0) Al . Therefore, it may be concluded that aluminum can nucleate on Al 3Zr particles with a small lattice mismatch 10.87%. Moreover, Al 3Zr p/Al composites fabricated by direct melt reaction have not only well-distributed solidification microstructure but also excellent mechanical properties.