The Effect of Tungsten on Microstructure and Mechanical Properties of Sintered Tantalum by Hot Pressing in a Vacuum

Document Type : Research Paper

Authors

1 Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran

3 School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran

Abstract

In this study, the effect of tungsten addition on the microstructure and mechanical properties of tantalum using hot pressing-sintering is investigated. Pure tantalum and tungsten powders were used to produce Ta-W alloys with varying tungsten content, including pure Ta, Ta-2.5 wt.% W, Ta-5 wt.% W, and Ta-7.5 wt.% W. The morphology of the powders was examined by scanning electron microscopy. Consolidation was performed via hot pressing-sintering at 1600 °C under vacuum conditions. Density was measured using the Archimedes method, and the microstructure was analyzed by optical microscopy. Hardness measurements were conducted on the sintered samples, and their deformation behavior was evaluated using uniaxial compression test at room temperature. The results indicated that the relative density of pure Ta is 97.5%, which decreases to 92.5% with the addition of 7.5 wt.% tungsten. With increasing tungsten content, the average grain size decreased while the porosity percentage increased. The properties of Ta-W alloys are influenced by three main characteristics: tungsten content, porosity percentage, and the grain size. The addition of tungsten to tantalum increased most mechanical properties, including hardness, compressive strength, yield strength, toughness, and resilience modulus, although ductility decreased by 10%.

Keywords

References

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Iranian Journal of Materials Forming
Volume 12, Issue 1
January 2025
Pages 10-17

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