<p>The temperature-dependent (0–300 K) elastic, mechanical, anisotropic, and thermodynamic properties of Ta–10%W, Ta–30%W and Ta–50%W (wt%) alloys were derived from 0 K density functional theory (DFT) calculations using the virtual crystal approximation (VCA). Subsequently, Varshni's well-known fit equation (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$C={C}_{0}-s/{[\text{e}\text{x}\text{p}}^{\left(\frac{t}{T}\right)}-1])$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>C</mi> <mo>=</mo> <msub> <mi>C</mi> <mn>0</mn> </msub> <mo>-</mo> <mi>s</mi> <mo stretchy="false">/</mo> <msup> <mrow> <mo stretchy="false">[</mo> <mtext>exp</mtext> </mrow> <mfenced close=")" open="("> <mfrac> <mi>t</mi> <mi>T</mi> </mfrac> </mfenced> </msup> <mo>-</mo> <mn>1</mn> <mrow> <mo stretchy="false">]</mo> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> was employed in this work to extrapolate the high-temperature elastic stiffness constants, and all results were compared with available experimental data. For the Ta–10%W and Ta–30%W alloys, the cubic elastic stiffness constants as well as the bulk, shear, and Young's moduli decrease together with the hardness values, while the Poisson's ratios increase with temperature. Conversely, for the Ta–50%W alloy, the cubic elastic stiffness constants, bulk modulus, and Poisson's ratio decrease, while the shear modulus, Young's modulus, and hardness increase significantly with increasing temperature. The hardness behavior of the investigated alloys illustrates a complex relationship, which is also discussed. The currently determined heat capacity curves (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$C_{V}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>C</mi> <mi>V</mi> </msub> </math></EquationSource> </InlineEquation>) of the alloys are in the range of Ta–10%W > Ta–30%W > Ta–50%W and are mainly related to the composition. In summary, the results of this study regarding the properties of Ta–10%W, Ta–30%W and Ta–50%W alloys are in good agreement with the available literature.</p>

A theoretical investigation of the temperature-dependent elastic, mechanical, and thermodynamic behavior of Ta–10%W, Ta–30%W and Ta–50%W alloys

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发表日期：

2026年7月23日

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E GÜLER,
Ş UĞUR,
M GÜLER,
G UĞUR

摘要

The temperature-dependent (0–300 K) elastic, mechanical, anisotropic, and thermodynamic properties of Ta–10%W, Ta–30%W and Ta–50%W (wt%) alloys were derived from 0 K density functional theory (DFT) calculations using the virtual crystal approximation (VCA). Subsequently, Varshni's well-known fit equation ( $C={C}_{0}-s/{[\text{e}\text{x}\text{p}}^{\left(\frac{t}{T}\right)}-1])$ $C = C_{0} - s / {[exp}^{(\frac{t}{T})} - 1])$ was employed in this work to extrapolate the high-temperature elastic stiffness constants, and all results were compared with available experimental data. For the Ta–10%W and Ta–30%W alloys, the cubic elastic stiffness constants as well as the bulk, shear, and Young's moduli decrease together with the hardness values, while the Poisson's ratios increase with temperature. Conversely, for the Ta–50%W alloy, the cubic elastic stiffness constants, bulk modulus, and Poisson's ratio decrease, while the shear modulus, Young's modulus, and hardness increase significantly with increasing temperature. The hardness behavior of the investigated alloys illustrates a complex relationship, which is also discussed. The currently determined heat capacity curves ( $C_{V}$ $C_{V}$ ) of the alloys are in the range of Ta–10%W > Ta–30%W > Ta–50%W and are mainly related to the composition. In summary, the results of this study regarding the properties of Ta–10%W, Ta–30%W and Ta–50%W alloys are in good agreement with the available literature.