A coherent set of model equations for various surface and interface energies in systems with liquid and solid metals and alloys

High Temperature Assessment of K-Tl Binary Liquid Alloy

“…The viscosity of the alloy decreases with the increase in temperatures as shown in the figure 5. To calculate the surface tension of alloy the surface tension of individual metals are calculated at different temperatures by using equation (20). The bulk excess free energy of individual potassium and thallium in liquid state at above temperatures are obtained by using equation (11).…”

“…The bulk excess free energy of individual potassium and thallium in liquid state at above temperatures are obtained by using equation (11). The geometrical structure factor and ratio of surface excess free energy to the bulk Excess free energy ( are considered 1.061 and 0.818 respectively [19,20]. In the case of negligible or unknown excess molar volume of the mixture, the partial molar volume is replaced by the molar volume of same component so that the partial surface area ( is obviously replaced by surface area ( ) of the same pure component [21][22][23].…”

Synthesis, characterisation and thermal behaviour of Cu-based nano-multilayer

“…(10a) of [48] the smallest thickness of the copper oxide layer of 37 nm is found that ensures the minimum of 400 nm wavelength of destructive interference if the refractive index of the CuO/Cu 2 O taken as 2.7 ± 0.1 (see p. 236 of [44]), where 400 nm is the lowest wavelength of light visible by humans. This means the thickness of the oxide layer on the micron-sized Cu-crystals is surely below 37 nm, which is less than 2 % of the total size of the Cucrystals, explaining why the presence of oxygen on Cu crystals seems negligible in Figs 7,8. From this maximum oxide thickness of 37 nm and from the molar volumes of Cu (7.09 cm 3 /mol [43]), CuO (12.4 cm 3 /mol [44]) and Cu 2 O (23.9 cm 3 /mol [44]) one can estimate the initial thickness of the Cu layer that is oxidised being below 11 nm.…”

“…13) the total initial interfacial area of Cu nanolayers is found as 0.0792 m 2 . Now, let us estimate the enthalpy part of the surface energy of solid Cu (= the maximum possible specific heat loss due to coarsening), similarly as it was done by Yakymovych et al [57], extrapolating the surface energy of the metal to T = 0 K, which equals about 2.50 J/m 2 (see Eq.10b in [8] and data from [39] and [58]). Multiplying this surface energy by the above found initial interface area, the maximum exothermic heat of -0.198 J follows.…”

“…One of the difficulties of today's modern joining technology is the brazing/joining of heat-sensitive materials [1][2][3][4][5][6]. Metallic joints with high mechanical strength require high cohesion energy between the atoms of the metallic filler and of the materials to be joined, while the cohesion energy increases monotonously with the melting point of the filler [7,8]. The most commonly used brazing materials are Cu (T m : 1085°C) [9], Ag (T m : 962°C) [10] and the eutectic Ag 60 -Cu 40 alloy (T m : 779°C) [11], which all require relatively high joining temperatures.…”