Influences of Initial Composition and Solid Back Diffusion on the Solidification Path of Al-Fe-Si Alloys

摘要

The influence of initial composition and the united solid back diffusion (SBD) effects on the calculated solidification paths (SP) of a series Al-Fe-Si ternary eutectic alloy were analyzed. The calculation programme was coupled with Thermo-Calc to calculate equilibrium for phase diagram information. The calculated results showed that initial compositions and SBD coefficient had important effects on SP of the Al-Fe-Si ternary eutectic alloys. The SP of the five Al-Fe-Si ternary alloys were divided into three categories: L → (L + β) → (L + α + β) → (L + α + β + Si), L → (L + α) → (L + α + β) → (L + α + β + Si), and L → (L + α) → (L + α + Si) → (L + α + β + Si). It was found that the volume fraction of eutectic phase decreases obviously with the increase of the SBD coefficient. Solute distribution coefficients of K_(Fe) and K_(Si) in Al-0.08Fe-4.8Si alloy were also calculated and analyzed.