ESTIMATION OF THERMODYNAMIC PARAMETERS OF Ni-Si BASE ALLOYS USING THE SEMI-EMPIRICAL MIEDEMA MODEL

Abstract

In this paper, we present a calculation method for evaluating the possibility of enhancing the thermal stability of nickel silicide by alloying with metals, which consists in determining the formation enthalpy (∆H) of nickel silicide using the Miedema model. Changes in formation enthalpy (∆H) were observed for nickel silicides that were alloyed with Mo, Pt, Pd, W, and Zr. The MAAT (Materials Analysis Applying Thermodynamics) software was used to calculate and plot the formation enthalpy of binary and ternary systems. Based on our calculations, we found that in binary systems, the optimum values to expand the formation enthalpy were 51.28 and 49.57 kJ/mol for nickel silicide alloys. For the ternary system, the results showed that adding Zr could increase monosilicide phase stability.

Calculation of Gibbs Free Energy of Iron Based Alloys Using Miedema's Model and Comparison with Experiment

“…Miedema's model .The semi-empirical Miedema model, as outlined in previous works [24,25], offers a direct means to calculate the formation enthalpy of both liquid and solid alloys that incorporate atoms from both transition and non-transition metals. Miedema devised a systematic approach for determining the formation enthalpy of metal alloy compounds, drawing inspiration from the Pauling scheme used for calculating the formation enthalpy (∆H) of molecular compounds.…”