Bulk and surface properties of liquid Al–Cr and Cr–Ni alloys

Abstract

The energetics of mixing and structural arrangement in liquid Al–Cr and Cr–Ni alloys hasbeen analysed through the study of surface properties (surface tension and surfacesegregation), dynamic properties (chemical diffusion) and microscopic functions (concentrationfluctuations in the long-wavelength limit and chemical short-range order parameter) in theframework of statistical mechanical theory in conjunction with quasi-lattice theory. TheAl–Cr phase diagram exhibits the existence of different intermetallic compounds in thesolid state, while that of Cr–Ni is a simple eutectic-type phase diagram at hightemperatures and includes the low-temperature peritectoid reaction in the range near aCrNi2 composition. Accordingly, the mixing behaviour in Al–Cr and Cr–Ni alloy melts was studiedusing the complex formation model in the weak interaction approximation and by postulatingAl8Cr5 andCrNi2 chemical complexes, respectively, as energetically favoured.