Thermophysical Measurements in Liquid Alloys and Phase Diagram Studies

Abstract

Towards the construction of pressure-dependent phase diagrams of binary alloy systems, both thermophysical measurements and thermodynamic modeling are employed. High-accuracy measurements of sound velocity, density, and electrical resistivity were performed for selected metallic elements from columns III to V and their alloys in the liquid phase. Sound velocity measurements were made using ultrasonic techniques, density measurements using the gamma radiation attenuation method, and electrical resistivity measurements were performed using the four probe method. Sound velocity and density data, measured at ambient pressure, were incorporated into a thermodynamic model to calculate the pressure dependence of binary phase diagrams. Electrical resistivity measurements were performed on binary systems to study phase separation and identify phase transitions in the liquid state.

Phase Diagram of Binary Alloy Nanoparticles under High Pressure

“…Ben Shalom et al reported the pressure diagram of the Ga-In system calculated with bulk thermodynamic data and highly accurate sound velocity and density data [ 56 ]. Similar works have been carried out for various systems, such as Bi-Sn [ 57 , 58 ], Bi-Sb [ 58 , 59 ], and Pb-Sn [ 58 , 59 ]. These studies demonstrate that this methodology can be applied to systems with high pressures of up to several GPa.…”

“… where is the bulk excess Gibbs energy under atmospheric pressure and is the excess volume, which can be expressed by Equation (24). where is the hypothetical volume of the alloy by ideal mixing, is the molar mass of the alloy, is the density of the alloy, is the molar mass of pure i , and is the density of pure i [ 56 , 57 , 58 , 59 ]. Here, it is assumed that the excess volume is constant at high pressures up to several GPa.…”

“…Studies of nanowires in the frame of the CALPHAD method can be found in the literature [ 52 , 53 , 54 , 55 ]. On the other hand, phase diagrams of various materials under high pressure have also been assessed using the framework of the CALPHAD method [ 56 , 57 , 58 , 59 ]. Ben Shalom et al reported the pressure diagram of the Ga-In system calculated with bulk thermodynamic data and highly accurate sound velocity and density data [ 56 ].…”

Thermodynamic Assessment of Molten Bix-Sn1−x (x = 0.1 to 0.9) Alloys and Microstructural Characterization of Some Bi-Sn Solder Alloys

“…In this regard, techniques and methods for investigating material structures at the atomic level promote exceptional scientific results, leading to the development of advanced materials for all practical areas of interest (e.g., metallurgy, medicine, electronics, etc.) [21][22][23][24][25][26][27][28][29][30]. The phenomenology associated with quantities such as Gibbs' enthalpy, thermodynamic activity, entropy, free enthalpy, etc., must be seen from the perspective of material structure (phase stability analysis or phase transformations of an alloy system).…”

Special Issue: Thermal Analysis of Materials

“…Thermal analysis contributes to the calculation of phase diagrams (CALPHAD), both through experimental phase diagrams and by providing thermodynamic data for optimizations. Krishon et al [ 17 ] extend the CALPHAD approach by calculating pressure dependence of several binary metal phase diagrams based on the temperature dependence of sound velocity and density data in liquid alloys. Thus, this Special Issue provides a sampling of the current use, diversity, and ongoing developments of techniques and approaches in the thermal analysis of materials.…”