Relationship between partial and average atomic volumes of components in Au-Ni alloys

In the framework of systematic science of alloys, the average molar property (volume and potential energy) functions of disordered alloys were established. From these functions, the average molar property functions, partial molar property functions, derivative functions with respect to composition, general equation of relationship between partial and average molar properties of components, difference equation and constraining equation of different values between partial and average molar properties, as well as general Gibbs-Duhem formula were derived. It was proved that the partial molar properties calculated from various combinative functions of average molar properties of alloys are equal, but in general, the partial molar properties are not equal to the average molar properties of a given component. This means that the partial molar properties cannot represent the corresponding properties of the component. All the equations and functions established in this work were proved to be correct by calculating the results of partial and average atomic volumes of components as well as average atomic volumes of alloys in the Au-Ni system.