Tungsten cemented carbide balls (typically made of tungsten-cobalt alloy or other cemented carbide materials) possess the following key physical and chemical properties, making them suitable for industrial applications, cutting tools, bearings, and other fields:
1. Physical Properties
Density: High, typically between 14.5–15.0 g/cm3 (depending on the specific composition, such as the WC-Co ratio).
Hardness: Extremely high, typically ranging from HRA 85–92 (Rockwell hardness) or HV 1200–1800 (Vickers hardness), with excellent wear resistance.
Strength: Extremely high compressive strength (up to 4000–6000 MPa), but low tensile strength and brittle fracture. Melting Point: The base material (e.g., tungsten carbide WC) of tungsten cemented carbide balls has an extremely high melting point of approximately 2870°C. However, in actual use, due to limitations in the binder phase (e.g., cobalt), high-temperature resistance is generally limited to 800–1000°C.
Thermal Conductivity: Moderate, approximately 50–100 W/(m·K), depending on composition.
Electrical Conductivity: Some conductivity, but lower than that of pure metal, with a resistivity of approximately 20–30 μΩ·cm.
Coefficient of Thermal Expansion: Low, approximately 4.5–6.0 × 10??/K, with good dimensional stability.
2. Chemical Properties
Corrosion Resistance: Tungsten cemented carbide balls are relatively resistant to acids and alkalis, but may corrode at high temperatures or in highly oxidizing environments (e.g., concentrated nitric acid).
Chemical Stability: Chemically stable at room temperature, they do not react readily with most substances. However, they may react with oxygen or certain chemicals at elevated temperatures. Oxidation Resistance: Oxidation begins at approximately 500–600°C in air; prolonged high-temperature exposure should be avoided.
3. Mechanical Properties
Toughness: Compared to other ceramic materials, tungsten cemented carbide balls (such as WC-Co) have better toughness due to the presence of cobalt, but still lower than metals.
Wear Resistance: Excellent, suitable for high-wear environments such as cutting tools, dies, and abrasive media.
Impact Resistance: Moderate, but due to the material's brittleness, its impact resistance is not as good as that of steel.
