Measurement of thermophysical properties of liquid metallic alloys in a ground- and microgravity based research program. The Thermolab Project

An outline of the Thermolab Project is reported with the aim of informing on the wide range of properties which are becoming available for some industrial alloys. Selected examples of experiments and properties are provided

Design of Composites by Infiltration Process: A Case Study of Liquid Ir-Si Alloy/SiC Systems

The design of processing routes involving the presence of the liquid phase is mainly associated with the knowledge of its surface and transport properties. Despite this need, due to experimental difficulties related to high temperature measurements of metallic melts, for many alloy systems neither thermodynamic nor thermophysical properties data are available. A good example of a system lacking these datasets is the Ir-Si system, although over the last fifty years, the structures and properties of its solid phases have been widely investigated. To compensate the missing data, the Gibbs free energy of mixing of the Ir-Si liquid phase was calculated combining the model predicted values for the enthalpy and entropy of mixing using Miedema's model and the free volume theory, respectively. Subsequently, in the framework of statistical mechanics and thermodynamics, the surface properties were calculated using the quasi-chemical approximation (QCA) for the regular solution, while to obtain the viscosity, the Moelwyn-Hughes (MH) and Terzieff models were applied. Subsequently, the predicted values of the abovementioned thermophysical properties were used to model the non-reactive infiltration isotherm of Ir-Si (eutectic)/SiC system

Composition transients and saturation phenomena at a liquid metal-vapour interface - the oxidatyion of tin and aluminium

This paper presents a detailed interpretation of the interface saturation data of liquid tin and aluminium drops, on the basis of a mathematical description of the interface evolution described in a previous paper. We also discuss the relevance of evolution times towards the stationary condition for both metal drops, which have given us a better understanding of the interface behaviour and also allowed us to attempt a quantitative estimation of the excess interface concentration

Models and experimentals on the surface tension of molten alloys: the case of Bi-Pb

The present work represents an experimentally based investigation on the surface properties of molten Bi, Pb and Bi-Pb alloys. The surface tensions of the two pure elements and of seven alloys were measured by the sessile-drop method over the temperature range 623-773 K

The effective oxydation pressure of indium-oxygen system.

A theoretical model on oxygen transport at the surface of liquid metals has been validated by dynamic surface tension measurements performed on liquid Indium as test metal. The oxygen contamination conditions have been obtained at different oxygen partial pressures under both low total pressure (Knudsen regime) and inert atmospheric pressure (Fick regime) conditions, confirming that an oxide removal regime occurs under an oxygen partial pressure much higher than the equilibrium one (the \u2018\u2018Effective Oxidation Pressure\u2019\u2019). Experimental results are reported which give a further insight on the relative importance of the various processes due to the oxygen mass transport between the liquid metal and the gas phase. The critical aspects involved in surface tension measurements of liquid metals, related to the problem of liquid metal\u2013oxygen interactions, are also underlined