Thermodynamic assessment of the Cu‐Mg‐Si system in its copper‐rich region

Abstract

A thermodynamic assessment of the ternary Cu-Mg-Si system was made in its copper-rich region in relation with the development of a thermodynamic database for Cu-Mg alloys. The adjustable parameters of the binary end-systems (Cu-Mg, Cu-Si and Mg-Si) were taken from the literature and those of the Cu-Mg-Si system were optimized using experimental thermodynamic and topological data. For the sake of simplicity, the solution phases were described with the substitutional solution model and the intermetallic compounds were treated as plain semi-stoichiometric phases ((A,B) p C q -type). The assessment developed is applicable for magnesium contents up to 20 wt% (i.e. magnesium mole fractions ≈0.4) and silicon contents up to 16 wt% (i.e. silicon mole fractions ≈0.3).

Phase diagram determination and thermodynamic modeling of the Cu-Mg-Si system

“…According to Bochvar et al, most of the experiments available in the literature were performed in the Cu-rich corner and there is a lack of accurate data on phase equilibria of the ternary compounds. There are several thermodynamic descriptions of this system [8][9][10] based on the literature data. However, these assessments are all limited to the Cu-rich corner and the liquidus surface cannot be reproduced using these thermodynamic parameters.…”