Microstructure and composition of cast Ti-47Al-2Cr-2Nb alloys produced by yttria crucibles

► Second-generation γ-TiAl alloys were melted and allowed to solidify in yttria crucibles. ► The effects of processing parameters on the microstructure and composition of the cast alloys were investigated. ► The cubic crystal structure of β phase was the primary solidification phase and there were three microsegregations in the lamellar microstructure. ► A kinetic view of the transport processes and interactions between the melt and the crucible was given. ► The increase of oxygen concentration in TiAl melts was governed by a rate equation of dct/dτ=−KA(c0−cs)/V.