Study on the Melting Temperature, the Jumps of Volume, Enthalpy and Entropy at Melting Point, and the Debye Temperature for the BCC Defective and Perfect Interstitial Alloy WSi under Pressure

Ştefan Ţălu,Dung Nguyen Trong,Van Cao Long,Hien Nguyen Duc,Hoc Nguyen Quang

doi:10.3390/jcs5060153

Ştefan Ţălu, Dung Nguyen Trong + Show 3 more

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https://doi.org/10.3390/jcs5060153

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Abstract

The objective of this study is to determine the analytic expressions of the Helmholtz free energy, the equilibrium vacancy concentration, the melting temperature, the jumps of volume, enthalpy the mean nearest neighbor distance and entropy at melting point, the Debye temperature for the BCC defective, the limiting temperature of absolute stability for the crystalline state, and for the perfect binary interstitial alloy. The results obtained from the expressions are combined with the statistical moment method, the limiting condition of the absolute stability at the crystalline state, the Clausius–Clapeyron equation, the Debye model and the Gruneisen equation. Our numerical calculations of obtained theoretical results were carried out for alloy WSi under high temperature and pressure. Our calculated melting curve and relation between the melting temperature and the silicon concentration for WSi are in good agreement with other calculations. Our calculations for the jumps of volume, enthalpy and entropy, and the Debye temperature for WSi predict and orient experimental results in the future.

Highlights

Metals and interstitial alloys [1,2,3,4,5] have been investigated by several research groups in the last decades due to their applications in various fields [6,7,8,9]
The equilibrium vacancy concentration of metals changes from 10− 4 to 10− 2 [20]; it has a significant influence on the thermodynamic quantities of crystals at high temperatures
The equilibrium vacancy concentration, the cohesive are in good agreement with the Figure shows the melting curve of WSicompressibility, at cSi = 1% obtained the fromlimiting the statistical moment method (SMM) for the thalpy and8 entropy, the isothermal temperatur perfect model and the for the defective model

Summary

Introduction

Metals and interstitial alloys [1,2,3,4,5] have been investigated by several research groups in the last decades due to their applications in various fields [6,7,8,9]. The melting temperature, the jumps of volume, enthalpy and entropy at the melting point, and the Debye temperature for the BCC defective and perfect binary interstitial alloy by combining the SMM, the limiting condition of the absolute stability of the crystalline state, the Clapeyron-Clausius equation, the Debye model and the Gruneisen equation are studied.

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