Interfacial reaction between Co-Cr-Mo alloy and liquid Al

The interfacial reaction between Co-Cr-Mo alloy and liquid Al was investigated using immersion tests. Microstructure characterization indicated that the Co-Cr-Mo alloy was corroded by liquid Al homogeneously, with the formation of a (Co,Cr,Mo)2Al9 layer close to alloy matrix and “(Cr,Mo)7Al45 + Al” layer close to Al. Kinetics analysis showed that the corrosion of the Co-Cr-Mo alloy followed a linear relationship with the immersion duration. Compared with pure Co-liquid Al reaction system, the alloying of Cr and Mo changed the solid-liquid interface structure, but the corrosion of the solid metal was still dominated by the dissolution of an intermetallic layer.