Diffusion and Atomic Mobilities in fcc Ni-Sn Alloys

Abstract

The composition-distance profiles in face-centered cubic (fcc) Ni-Sn alloys at 1173, 1223, 1273, and 1323 K were measured by means of electronic probe microanalysis (EPMA) using Ni/Ni-7.3at.%Sn diffusion couples. Based on the available thermodynamic information and various experimental diffusion coefficients, the atomic mobilities of Ni and Sn in fcc Ni-Sn alloys were assessed as a function of temperature and composition in terms of the CALPHAD method using the DICTRA Ò software package. Optimized mobility parameters are presented. Comparisons between the calculated and measured diffusion coefficients show that most of the experimental information can be reproduced reasonably. The obtained mobility parameters can also predict satisfactorily the composition-distance profiles of the Ni/Ni-7.3at.%Sn diffusion couples determined in the present work.

Experimental investigation and thermodynamic modeling of the Au–Ge–Ni system

“…The investigated vertical section in this work starts from the AuGe experimental eutectic point (28 at.% Ge) to pure Ni. However, the calculated Au-Ge eutectic composition is at 29.5 at.% Ge [18], which leads to the higher calculated transition temperature for the Au-Ge-Ni ternary alloy 1. The calculated liquidus temperature (ca.…”

“…Combining the previous assessments of the Au-Ge [18], Au-Ni [19], and Ge-Ni [20] binary systems, we optimized the Au-Ge-Ni ternary system on the basis of the experimental data obtained in the present work. The optimization of the model parameters for various phases in the Au-GeNi ternary system was conducted using the PARROT module [23] in the Thermo-calc software package developed by Sundman et al [24].…”

“…In the present optimization, the thermodynamic parameters of the Au-Ge, Au-Ni, and Ge-Ni binary subsystems are taken from [18], [19], and [20], respectively.…”

“…Au;Ni , and L u Ge;Ni are the interaction parameters taken from the corresponding binary systems [18][19][20].…”

“…The optimization of the model parameters for various phases in the Au-GeNi ternary system was conducted using the PARROT module [23] in the Thermo-calc software package developed by Sundman et al [24]. The thermodynamic parameters for all condensed phases in the Au-Ge-Ni ternary system obtained in the present work together with the thermodynamic parameters of the three binary systems Au-Ge, Au-Ni, and Ge-Ni from literature [18][19][20] are summarized in Table 3. Figure 6 shows the calculated isothermal section at 600°C.…”