An investigation on interfacial reaction between in-situ melted AZ91D magnesium alloy and ceramic shell mold during investment casting process

► Mechanisms of mold-metal reaction and investment adhesion were proposed. ► Granular black residues comprised mainly MgO and Mg2Si formed on casting surface. ► MgO and MgAl2O4 on shell surface and MgO and Mg2Si under shell surface were formed. ► Using flux with AZ91D granules prevented investment adhesion to casting surface.