Competition between metastable and stable phases during solidification of Al-Fe-V-Si alloy

Al-Fe-V-Si alloys have been produced by strip casting and spray casting. These processes offer relatively fast solidification rates and can produce near net shape products such as thin gauge strips or billets with the fine microstructure free from segregation. It has been shown that the microstructure of the alloys consists of various phases; bcc phase, microquasicrystalline phase, icosahedral phase, and the newly found hexagonal phase. All the phases are structurally related and have close orientation relationship among them. The volume fraction and distribution of these phases depend on the solidification rate and the degree of undercooling. The degree of recalescence occurring during solidification also affects the final microstructure, in that there is a transformation of thermally unstable primary phases to the stable phases during solidification.