The microstructure of multiphase Ni-25Al-15Cr (at. pct) intermetallic alloy consists of dendritic arms (β-NiAl phase) and interdendritic regions (γ/γ’two phases) under homogenization followed by air cooling condition. Furnace cooling following homogenization does not significantly influence its microstructure. However, the effects of aging treatment on the microstructure strongly depend on cooling rates following homogenization. A singIe phase γ’ layer with a α-Cr ’spouse’layer is observed surrounding the dendritic arms- the formation of this ’couple’ is attributed to a four-phase invariant quasi-peritectoid, i.e. β + γ = γ’ + α-Cr.
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