Theoretical studies of mutual diffusivities and surface properties in Cd-Ga liquid alloys

Abstract

The mutual diffusion coefficients, activation energy for diffusion, surface concentration and surface tension of the liquid Cd-Ga alloys have been calculated throughout the concentration range using energetics obtained from the theoretical model fits of the experimental thermodynamic data. Our calculations show that Cd-Ga liquid alloys showed immiscibility at a temperature of 723 K between 0.4 and 0.5 atomic fraction of Cd. Within this concentration region and temperature, the mutual diffusion coefficients approached zero values and the activation energy for diffusion reached high peak values of 220 J/mol. It was also observed that within the region of immscibility, the diffusion coefficients do not obey Arrhenius relation over a wide range of temperature.

Assessment of Surface Tension and Viscosity of In-Zn melt

“…The self-association model [4,5] is a statistical mechanical formulation for studying phase segregating binary liquid alloys. According to this model, one mole of a binary liquid alloy A-B is assumed to consist of N A (=Nc A ) atoms of elemental metal A and N B (=Nc B ) atoms of elemental metal B situated at equivalent sites, N being the total number of atoms, and c A and c B the mole fraction concentrations of A and B respectively.…”

“…According to this model, one mole of a binary liquid alloy A-B is assumed to consist of N A (=Nc A ) atoms of elemental metal A and N B (=Nc B ) atoms of elemental metal B situated at equivalent sites, N being the total number of atoms, and c A and c B the mole fraction concentrations of A and B respectively. There is short ranged atomic interaction between the nearest neighbours that forms a polyatomic matrix leading to the formation of like atom clusters or selfassociates of the type iA and jB, where i and j are the numbers of atoms in the clusters of elements A and B respectively [5]. In the framework of self association model, the following expressions are used in computing the thermodynamic functions of binary liquid alloys [5]:…”

“…There is short ranged atomic interaction between the nearest neighbours that forms a polyatomic matrix leading to the formation of like atom clusters or selfassociates of the type iA and jB, where i and j are the numbers of atoms in the clusters of elements A and B respectively [5]. In the framework of self association model, the following expressions are used in computing the thermodynamic functions of binary liquid alloys [5]:…”

“…In computation of both surface tension and viscosity in this work, we employ the energetics like interaction energy, enthalpy of mixing etc. computed from self-association model [4][5][6]. Due to scanty of experimental data of surface tension and viscosity as function of composition, we intend to carry out comparative analyses for both of these properties.…”

Energetics of mixing and transport phenomena in Cd-X (X=Pb, Sn) melts

“…In the current work we have focused our attention towards the review of the thermodynamics of the formation of liquid Cd-Pb and Cd-Sn alloys at 773K and the transport phenomena in them. For the review of the thermodynamics of mixing in the liquid alloys as function of composition we employ self-association model based on the formation of like atom clusters [12,13]. The self-association model is assumed to be good for regular alloys [14], and to our interest we intend to apply it to the alloys, which are not strictly regular solutions but have their behaviour close to that of regular solution.…”