Tungsten cemented carbide balls are typically composed of tungsten carbide (WC) with a metal binder such as cobalt (Co). They possess the following key physical properties:
1. High Hardness: Tungsten cemented carbide balls have extremely high hardness, typically ranging from HRA 85-93 (Rockwell hardness) or HV 1200-2000 (Vickers hardness), approaching that of diamond, making them suitable for wear-resistant applications.
2. High Density: Density generally ranges from 13-15 g/cm3, depending on the composition (such as the WC-Co ratio). For example, WC-Co carbide has a density of approximately 14.5 g/cm3.
3. High Strength: Compressive strength is extremely high, reaching 4000-6000 MPa, but tensile strength is relatively low, approximately 1000-2000 MPa, exhibiting some brittleness.
4. Wear Resistance: Due to their high hardness and strong bonding strength, tungsten cemented carbide balls have excellent wear resistance and are suitable for high-wear environments such as bearings and valves.
5. Thermal Stability: Tungsten cemented carbide balls can maintain high hardness and strength at high temperatures (approximately 800-1000°C), but performance may degrade at excessively high temperatures.
6. Thermal Conductivity: The thermal conductivity is approximately 50-100 W/(m·K), which is better than many metals but lower than pure copper or silver.
7. Elastic Modulus: High rigidity, with an elastic modulus of approximately 400-700 GPa, results in minimal deformation, making it suitable for precision applications.
8. Thermal Expansion Coefficient: Low, approximately 4-6 × 10??/°C, and excellent dimensional stability.
9. Magnetic Properties: Cobalt-containing cemented carbides are weakly magnetic, depending on the cobalt content; cobalt-free cemented carbides (such as WC-TiC) are generally non-magnetic.
10. Electrical Conductivity: Its electrical conductivity is low, with a resistivity of approximately 20-30 μΩ·cm, making it a poor conductor, but it can be used in certain electrical contact applications.
11. Surface Finish: Tungsten cemented carbide balls can achieve an extremely high surface finish after polishing, making them suitable for precision sealing or grinding applications.
These properties make tungsten cemented carbide balls widely used in industrial applications such as precision bearings, seals, grinding media, and wear-resistant parts. Specific performance may vary slightly depending on the alloy composition and manufacturing process (such as sintering method).
