Tungsten Carbide/Cobalt/Chromium-Nickel (WC 90/Co 6/Cr.Ni 4) is a high-performance composite engineered for extreme wear resistance, hardness, and toughness. This material combines tungsten carbide’s exceptional strength with cobalt’s ductility and the corrosion resistance of chromium and nickel, creating a balanced alloy ideal for heavy-duty industrial use (Lassner et al., 2000; Fang et al., 2014).
Material Overview
Physically, tungsten carbide (WC) is one of the hardest known materials, with a hardness approaching that of diamond and a density of around 15 g/cm³. The addition of 6% cobalt (Co) serves as a binder phase, improving toughness and preventing the brittleness associated with pure WC. The 4% chromium-nickel (Cr.Ni) addition refines the microstructure and introduces enhanced corrosion resistance and oxidation stability (Kny et al., 1986; Qing & Xiang, 2016).
Chemically, the WC–Co–Cr.Ni system maintains tungsten carbide’s intrinsic resistance to wear and chemical attack, while cobalt and nickel provide ductility and fracture toughness. Chromium inhibits coarse WC grain growth during sintering, ensuring a uniform, fine-grained structure that improves mechanical integrity and extends tool life (Kurlov & Gusev, 2013).
Microstructure and Processing
The microstructure of WC 90/Co 6/Cr.Ni 4 consists of fine WC grains embedded in a metallic Co–Cr–Ni binder matrix. This structure is typically achieved through liquid-phase sintering or hot isostatic pressing, which produce a dense, defect-free composite. The Cr.Ni addition forms a protective oxide layer on the surface, enhancing the material’s behavior in weakly acidic or basic media and in wastewater applications (Konyashin, n.d.).
Applications and Advantages
Cutting and drilling tools. WC 90/Co 6/Cr.Ni 4 is extensively used in cutting inserts, drill bits, and mining tools due to its high hardness, resistance to abrasion, and thermal stability. It performs reliably under heavy loads and high temperatures, maintaining sharpness and dimensional stability (Fang et al., 2014; Ettmayer, 1989).
Valves, seals, and wear parts. The composite’s excellent corrosion and erosion resistance make it ideal for valve seats, seal rings, and pump components in chemical, oil, and gas processing environments (Kny et al., 1986; Zhang et al., 2018).
Thermal and chemical stability. The presence of chromium and nickel allows the alloy to perform well in weakly oxidizing or reducing environments, maintaining surface integrity in marine, chemical processing, and sewage treatment applications (Qing & Xiang, 2016).
Performance Benefits
- Extreme hardness (~1800–2000 HV) and wear resistance comparable to diamond.
- High toughness and impact resistance from cobalt and nickel binders.
- Superior corrosion and oxidation resistance due to chromium and nickel.
- Thermal stability and chemical inertness for operation in harsh conditions.
- Uniform, fine-grained microstructure ensuring extended service life.
Goodfellow Availability
Goodfellow supplies WC 90/Co 6/Cr.Ni 4 as powder, rod, and solid components suitable for advanced manufacturing, coatings, and wear-resistant applications. This composite’s combination of mechanical toughness, corrosion resistance, and high hardness makes it ideal for extreme industrial environments.
Explore Tungsten Carbide/Cobalt/Chromium-Nickel (WC 90/Co 6/Cr.Ni 4) and related materials 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
- Fang, Z. Z., Koopman, M., & Wang, H. (2014). Cemented Tungsten Carbide Hardmetal – An Introduction. https://doi.org/10.1016/B978-0-08-096527-7.00004-0
- Konyashin, I. Yu. (n.d.). Cemented Carbides. https://doi.org/10.1016/b978-0-12-804173-4.00024-7
- Qing, J., & Xiang, W. (2016). Preparation Method for WC–(Co+Ni+Cr) Composite Binding-Phase Hard Alloy.
- Kny, E., Bader, T., Hohenrainer, C., & Schmid, L. (1986). Korrosionsresistente, Hochverschleißfeste Hartmetalle. Materials and Corrosion – Werkstoffe und Korrosion. https://doi.org/10.1002/MACO.19860370505
- Kurlov, A. S., & Gusev, A. I. (2013). Tungsten Carbides: Structure, Properties and Application in Hardmetals.
- Kurbanbekov, S., Kozhakhmetov, Y., Skakov, M., Seitov, B., Aidarova, M., & Tabiyeva, Y. (2024). Properties, Advantages, and Prospects of Using Cobalt-Free Composites Based on Tungsten Carbide in Industry. Materials. https://doi.org/10.3390/ma18010129
- Zhang, J., Saeed, M. H., & Li, S. (2018). Recent Progress in Development of High-Performance Tungsten Carbide-Based Composites. https://doi.org/10.1016/B978-0-08-102166-8.00013-X
- Ettmayer, P. (1989). Hardmetals and Cermets. Annual Review of Materials Science. https://doi.org/10.1146/ANNUREV.MS.19.080189.001045