Identification of metastable phases in strip-cast and spray-cast Al-Fe-V-Si alloys

Abstract

Second phases have been investigated in the strip-cast and/or spray-cast Al-Fe-V-Si alloy, and found to be classified into three different types, e.g. icosahedral phase, newly found hexagonal phase, and bce alpha-AlFeSi. Convergent Beam Electron Diffraction (CBED) analysis shows that the space group of the hexagonal phase is P6/mmm and the lattice parameter of the phase is a=2.514 and c=1.257 nm of which cia ratio is 0.5. Crystallographic orientation relationships among the phases were determined by electron diffraction. All the phases have similar atomic arrangements, which are constructed by (Fe + V) and (Al + Si) icosahedra, and thereby providing close orientation relationships among them.