A solidification model for prediction of castability in the precipitation-strengthened nickel-based superalloys

作者：Moosavy Homarn Naffakh^*; Aboutalebi Mohammad Reza; Seyedein Seyed Hossein; Mapelli Carlo

来源：Journal of Materials Processing Technology, 2013, 213(11): 1875-1884.

DOI：10.1016/j.jmatprotec.2013.04.019

• Solidification model
• Nickel-based superalloys
• Castability
• Microsegregation
• Hot tearing

The Scheil equation was used to model the solidification path, microsegregation of alloying elements in the interdendritic regions, solidification temperature ranges, and to predict the formation of secondary structures and the castability behavior of as-cast superalloys. 4 experimental alloys with pre-specified gamma-Ti,Nb,Al,Mo composition containing different Nb, Ti and Al contents were designed using vacuum induction melting furnace. The produced as-cast superalloys were characterized using optical and scanning electron microscopy equipped with energy dispersive X-ray spectrometer and TG-DSC analysis. The experiments showed logic conformity to the modeling results. The model and experiment confirmed the highest segregation behavior for Ti and Nb. All the experimental superalloys indicated the remarkable tendency to form secondary eutectic structures at the last stages of solidification. Superalloy with chemical composition of gamma-3.5%Mo,1.8%Al,4%Ti,2.9%Nb showed the shorter solidification temperature range and the best castability.

• 出版日期2013-11