The selection of sintering process parameters is a critical aspect during the fabrication of medium-entropy alloy (MEA) via powder metallurgy (PM) route. The change in the values of sintering process parameters such as sintering temperature (ST), heating rate (HR) and dwell time (DT) can result in variability of mechanical properties due to metastable nature of phases in MEA. To elucidate the complex effect of microwave sintering parameters on the mechanical property of an Mg-based MEA(Mg60Ti24.24Zn9.66Nb6.1), central composite design (CCD) was employed. Further, two evolutionary optimization algorithms were incorporated to identify optimum process parameters which optimized the response variables, i.e., volumetric shrinkage (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$V_{s}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>V</mi> <mi>s</mi> </msub> </math></EquationSource> </InlineEquation>) and compressive strength (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\sigma_{{{\text{cs}}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>σ</mi> <mtext>cs</mtext> </msub> </math></EquationSource> </InlineEquation>). The samples fabricated using the optimized parameters (ST: 867 °C, HR: 30 °C/min, DT: 34 min) exhibited <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$V_{s}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>V</mi> <mi>s</mi> </msub> </math></EquationSource> </InlineEquation> of 20.82 ± 0.4% and <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\sigma_{{{\text{cs}}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>σ</mi> <mtext>cs</mtext> </msub> </math></EquationSource> </InlineEquation> of 347.1 ± 6.8 MPa, in line with the model prediction. Further, the sample fabricated at optimum parameters were subjected to mechanical property degradation test in the simulated body fluid environment.he sample demonstrated a reduction in <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\sigma_{{{\text{cs}}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>σ</mi> <mtext>cs</mtext> </msub> </math></EquationSource> </InlineEquation> and yield strength value by 15.98% and 12.51%, respectively, after a 7 day immersion period. Notably, the degradation in mechanical properties was found be lower compared to existing PM fabricated magnesium-based materials. Finally, an efficiency parameter was proposed to rank and order the biomedical compositionally complex alloys on the basis of their young’s modulus, yield strength and fracture strain.

Process Optimization and Biomechanical Stability Assessment of MgTiZnNb Medium-Entropy Alloy

期刊论文
发表日期：

2025年7月4日

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Priyabrata Das,
Pulak Mohan Pandey

摘要

The selection of sintering process parameters is a critical aspect during the fabrication of medium-entropy alloy (MEA) via powder metallurgy (PM) route. The change in the values of sintering process parameters such as sintering temperature (ST), heating rate (HR) and dwell time (DT) can result in variability of mechanical properties due to metastable nature of phases in MEA. To elucidate the complex effect of microwave sintering parameters on the mechanical property of an Mg-based MEA(Mg₆₀Ti_24.24Zn_9.66Nb_6.1), central composite design (CCD) was employed. Further, two evolutionary optimization algorithms were incorporated to identify optimum process parameters which optimized the response variables, i.e., volumetric shrinkage ( $V_{s}$ $V_{s}$ ) and compressive strength ( $\sigma_{{{\text{cs}}}}$ $σ_{cs}$ ). The samples fabricated using the optimized parameters (ST: 867 °C, HR: 30 °C/min, DT: 34 min) exhibited $V_{s}$ $V_{s}$ of 20.82 ± 0.4% and $\sigma_{{{\text{cs}}}}$ $σ_{cs}$ of 347.1 ± 6.8 MPa, in line with the model prediction. Further, the sample fabricated at optimum parameters were subjected to mechanical property degradation test in the simulated body fluid environment.he sample demonstrated a reduction in $\sigma_{{{\text{cs}}}}$ $σ_{cs}$ and yield strength value by 15.98% and 12.51%, respectively, after a 7 day immersion period. Notably, the degradation in mechanical properties was found be lower compared to existing PM fabricated magnesium-based materials. Finally, an efficiency parameter was proposed to rank and order the biomedical compositionally complex alloys on the basis of their young’s modulus, yield strength and fracture strain.