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The energetics of mixing in the Fe–Cr liquid phase has been analysed through the study of the concentration dependence of various thermodynamic, structural, surface (surface tension and surface segregation) and transport properties (diffusivity and viscosity) by the first or the Quasi-Chemical Approximation (QCA) for regular solutions, developed by Bhatia and Singh, in the framework of statistical mechanical theory in conjunction with the Quasi-Lattice Theory (QLT). There is some disagreement regarding the assessments of the Fe–Cr phase diagram available in the literature, but all versions reported indicate the presence of a σ intermediate phase in the solid state. Since the arrangement of molecules in a liquid alloy is in some respects similar to that of a crystal, at least near to its melting temperature, the complex formation phenomenon in Fe–Cr melts has been described in terms of the microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter). [ABSTRACT FROM AUTHOR]

Abstract: The mixing behaviour of liquid Bi–In alloys has been described in terms of energetics and structure through the study of their thermodynamic, surface and structural properties by using the Complex Formation Model (CFM) in the weak interaction approximation and by postulating BiIn-chemical complexes as energetically favoured. The new Bi, In and Bi–In surface tension experimental data set, obtained by the large drop method in the temperature range 553–873 K, has been analysed in the framework of the CFM and compared with the calculated values as well as with corresponding literature data. The structural characteristics of Bi–In melts are described by the two microscopic functions, i.e. the concentration fluctuations in the long-wavelength limit and the Warren–Cowley short-range order parameter. [Copyright &y& Elsevier]

The wetting phenomena of molten alloy/ceramic substrate depend on the bonding characteristics of liquid alloys and ceramics as well as on the magnitude of interactive forces at the interface. According to this, the first step of this investigation is to determine the surface properties of Ag–Cu, Ag–Ti and Cu–Ti liquid alloys. The energetics of mixing in liquid alloys has been analysed through the study of surface properties (surface tension and surface composition) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the frame of statistical mechanical theory in conjunction with the quasi-lattice theory (QLT). The results obtained for these binary systems have been extended to the ternary Ag–Cu–Ti system. Combining the Young and the Dupre´ equations, the computed results of surface tension together with contact angle data have been used to calculate the work of adhesion and, in the case of non-reactive wetting, the interfacial tension between the solid substrate and the liquid alloys over the whole concentration range. The evaluation of the interfacial tension values is determined from calculated and measured data using solid surface tension data from literature. These results provide more information on the characteristics of metal–ceramic systems, and are therefore useful in guiding experiments, or in predicting the surface properties of metallic systems with similar characteristics as well as their wetting behaviour in contact with ceramic materials. [Copyright &y& Elsevier]

Abstract: In the present work, the surface tension of liquid Si and Ge has been measured by the pendant/sessile drop combined method over the temperature range of 1723–1908K and 1233–1313K, respectively. The new surface tension data, the molar volumes and the melting temperatures of silicon and germanium as well as the excess Gibbs energy data of the Ge–Si liquid phase are the inputs for Calphad type modelling to study the mixing behaviour in alloy melts. The energetics of mixing in liquid Ge–Si system has been analysed through the study of the concentration dependence of various thermodynamic (activity, enthalpy of mixing, Gibbs energy of mixing), surface (surface tension and surface composition) and transport (diffusivity) properties as well as the microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of statistical mechanical theory in conjunction with the Quasi-Lattice Theory (QLT). [Copyright &y& Elsevier]

The linear and exponential temperature-dependent interaction parameters for excess Gibbs free energy of mixing of constituent binary subsystems in liquid Al–Mg–Si alloys were optimized using the framework of R–K polynomials. The optimized parameter were then used to estimate the excess Gibbs free energy of mixing and activity of the ternary system at 1100 K, 1200 K, 1300 K and 1400 K employing GSM, Kohler and Toop models. The surface tensions of the systems were calculated using Butler's equations. Kaptay's equation was used to calculate the viscosity of binary subsystems as well as ternary mixture employing the exponentially optimized coefficients of R–K polynomials. The optimized parameter were further used to compute the concentration fluctuation in long wavelength limit for Al–Mg–Si alloys. [ABSTRACT FROM AUTHOR]

Among manufacture techniques for SiC ceramics, reactive infiltration has proven to be the most efficient. However, materials manufactured with this technique present minimum 10% of unreacted silicon. Si hinders the performance of the material. The replacement of Si with a Me x Si y can improve the performance of the composite. Since Me–Si alloys wet carbon materials, they are suitable candidates to be used as infiltrants in SiC/Me x Si y composite production via reactive infiltration. To optimize the process, it is necessary to identify the mechanisms involved in infiltration and the parameters governing them. A basic wetting study can provide a clear understanding of the operative mechanisms and allow obtaining accurate parameters. In this work, the wetting behavior of silicon-cobalt alloys on carbon materials was studied using the sessile drop technique. The influence of temperature, composition and carbon crystallinity was evaluated, observing a strong dependence of process kinetics and reactivity with temperature and carbon crystallinity. [ABSTRACT FROM AUTHOR]

Abstract: The main objective of this work is to determine the wetting behaviour of lead-free solders on copper substrates in view of their applications in electronic industry. The wetting behaviour of X–In–Sn (X=Au, Bi) ternary molten alloys in contact with copper has been studied and compared with the corresponding behaviour of their binary subsystems with a particular attention to the In–Sn/Cu system. The contact angle measurements on Cu-plates were performed by using a sessile drop apparatus. The solder/copper interface was characterised by the SEM-EDS analysis. [Copyright &y& Elsevier]

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. In addition the wetting behaviour of the eutectic Bi–Pb alloy on AISI 316L substrate was also investigated in the same temperature range. The results obtained show general agreement with other reported measurements on pure elements and their alloys as well as with calculated surface tension values obtained by the application of the compound formation model (CFM). [Copyright &y& Elsevier]