6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Enhancing the Thermodynamic Stability and Mechanical Properties of FCC Platinum through Vanadium and Chromium Alloying, for jewellery application: A DFT Study

8 Jul 2026, 16:20
1h 20m
Great Hall ( University of the Western Cape)

Great Hall

University of the Western Cape

Poster Presentation Track A - Physics of Condensed Matter and Materials Poster Session 2

Speaker

Mr Mawisha Jan Mafifi (University of Pretoria)

Description

In the ever-evolving world of renewable energy, metallurgy, medicine, jewellery, and fuel cells, platinum (Pt) remains a key mineral in these industries. Nonetheless, Pt in its purest shape is relatively soft, thus vulnerable to surface scratching, a distress in the jewellery sector. As such, alloying Pt to enhance its mechanical integrity is crucial for improving its scratching resistance. For this reason, density functional theory (DFT) within the Quantum Espresso package was deployed to investigate the contribution of alloying Pt with high corrosion resistance vanadium (V) and chromium (Cr) at various concentrations, x. For thermodynamic stability investigation, the calculated formation energies range from -0.5 to -3 eV for alloy composition of 3<x<19 for both V and Cr. This suggests that Pt-Vx and Pt-Crx formation is exothermic, hence supporting the feasibility of the synthesis process at 0K. The calculated elastic constants C11 (324.34 GPa), C12 (219.48 GPa), C44 (86.83 GPa), and C` (52.43 Gpa) of pristine FCC Pt agree very well with experimental data and also satisfy the Born-Huang stability criteria. The obtained elastic values increase as the concentrations of Cr and V increase, enhancing the elastic stability of Pt.
Furthermore, Pt-Vx and Pt-Crx alloys possess great bulk, Young, and shear modulus at different concentrations when compared to pristine FCC Pt. It is further noticed that the hardness of the Pt alloy system doubles as the V/Cr concentration approaches 19%. The ductility of Pt alloy is maintained when V/Cr concentration increases, and its magnitude reduces to 2.5 GPa at x=19%. These DFT findings suggest possibility of durability of Pt-based jewellery when alloyed with V/Cr.

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Author

Mr Mawisha Jan Mafifi (University of Pretoria)

Co-authors

Dr Donald Mkhonto (MINTEK) Dr Edwin Mapasha (University of Pretoria) Dr Maje Phasha (MINTEK) Dr Mwende Mbilo (University of Pretoria)

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