Tungsten/Silver (W90/Ag10) is a high-performance composite that combines the exceptional density and thermal stability of tungsten with the superior electrical and thermal conductivity of silver. This material is not a true alloy but rather a composite in which tungsten particles are embedded in a silver matrix, resulting in a unique combination of strength, conductivity, and corrosion resistance (Es-saheb & M., 2015; Lassner et al., 2000).
Material Overview
Tungsten contributes its hallmark properties of high melting point (3422 °C), high density (19.3 g/cm³), and outstanding wear resistance, making it ideal for high-temperature or high-load applications. Silver, by contrast, is known for its excellent electrical (63 × 10⁶ S/m) and thermal conductivity, low contact resistance, and ductility. The W90/Ag10 composite therefore balances thermal stability with high conductivity, outperforming many conventional contact materials in both performance and cost efficiency (Yunhua & Qihong, 2005).
The composite is typically produced by winding silver wire around tungsten wire followed by vacuum sintering. During this process, molten silver fills the gaps between tungsten filaments, creating a dense, cohesive structure that maintains excellent conductivity and strength. Powder metallurgy and sintering methods—with potential use of sintering aids such as phosphorus—are also used to achieve optimal bonding and microstructural uniformity (Lei et al., 2017).
Microstructure and Chemical Behavior
Unlike true intermetallic alloys, W–Ag composites feature phase separation between tungsten and silver. This dual-phase structure enables superior mechanical and electrical performance over a broad temperature range. Tungsten phases provide rigidity and wear resistance, while the silver matrix ensures efficient electron and heat transport. Moreover, the presence of tungsten significantly enhances the anti-sulfurization behavior of silver, mitigating corrosion caused by sulfur-bearing environments (Shih et al., 2023).
Applications and Advantages
Electrical contacts. The W90/Ag10 composite is extensively used in switchgear contacts, relays, and circuit breakers where both high conductivity and arc erosion resistance are required. Tungsten provides the hardness and arc-resistant properties, while silver ensures low contact resistance and efficient current flow (Kiyotaka et al., 1999).
Corrosion-resistant components. The material’s enhanced anti-sulfide performance makes it a cost-effective alternative to palladium-silver alloys, especially in industrial and electronic environments where sulfurization or oxidation can degrade conventional contacts (Shih et al., 2023).
Aerospace and high-temperature systems. The composite’s thermal stability, high density, and low abrasion make it suitable for aerospace connectors, actuators, and heat-resistant contact materials operating in extreme thermal or vibrational environments (Lei et al., 2017).
Performance Benefits
- Combines high melting point (3422 °C) with excellent electrical and thermal conductivity.
- Outstanding wear and arc resistance for long service life in electrical contacts.
- Improved anti-sulfurization and corrosion resistance in aggressive environments.
- High density and mechanical strength suitable for aerospace and industrial use.
- Stable microstructure produced via vacuum sintering and powder metallurgy.
Goodfellow Availability
Goodfellow supplies W90/Ag10 composites in powder form for use in electrical, aerospace, and thermal management applications. Its unique balance of conductivity, wear resistance, and corrosion protection makes it a preferred material for advanced engineering solutions.
Explore Tungsten/Silver (W90/Ag10) and other advanced composites in Goodfellow’s online catalogue: Goodfellow product finder.
References
- Lassner, E., Schubert, W.-D., Lüderitz, E., & Wolf, H. U. (2000). Tungsten, Tungsten Alloys, and Tungsten Compounds. https://doi.org/10.1002/14356007.A27_229
- Es-saheb, S. M. A., & M. (2015). Homogenous Silver-Tungsten Composite Production for Electrical Contacts. Research Journal of Applied Sciences, Engineering and Technology. https://doi.org/10.19026/RJASET.9.1439
- Yunhua, X., & Qihong, C. (2005). Preparation Technology of Tungsten Copper or Tungsten Silver Composite Material.
- Shih, H.-J., Pan, J.-R., Chung, C., & Lee, Y.-C. (2023). The Effects of Tungsten Addition on the Microstructure and Anti-Sulfurization of Silver. Materials Characterization. https://doi.org/10.1016/j.matchar.2023.113425
- Lei, Z., Xiao, K., Zhou, J., Guiru, J., & Changjiang, L. (2017). Nano-Composite Lubricating Ultralow-Abrasion Aerospace Electric Contact Material and Preparation Method Thereof.
- Kiyotaka, M., Kozo, I., Yasuhiro, H., & Kazuhiro, M. (1999). Silver-Tungsten/WC Base Sintered Type Electric Contact Material and Its Production.