Interaction between Two Ni-Base Alloys and Ceramic Moulds

The interfacial reactions between ceramic moulds and DZ417G and DZ125 superalloys were investigated. The microstructure and composition of the interface region were observed by optical microscope, X-ray diffraction and scanning electron microscope with energy dispersive spectroscopy. The results showed that (Al1-xCrx)2O3 solid solution phase with pink color was formed from the dissolution of Cr2O3 and Al2O3 and vapour phase, which was transferred to the reaction surfaces. The reaction layer thicknesses of DZ417G and DZ125 alloys were about in the range of 40-50μm. The interface reaction product between DZ417G alloy and ceramic mould was TiO2 and the product between DZ125 alloy and ceramic mould was HfO2.