Tungsten carbide (WC) is a hard and wear-resistant material known for its exceptional toughness and durability. It is widely used in industrial applications requiring high performance under harsh conditions. Here are some key parameters for tungsten carbide:
- Chemical Formula: WC
- Molecular Weight: Approximately 195.85 g/mol
- Crystal Structure: Tungsten carbide has a hexagonal crystal structure, belonging to the space group P63/mmc.
- Density: The theoretical density of tungsten carbide is around 15.63 g/cm³, making it one of the densest carbides.
- Melting Point: Its melting point is extremely high, around 2870°C, which allows it to maintain its structural integrity in high-temperature applications.
- Hardness: Tungsten carbide is renowned for its hardness, with a Vickers hardness value that can reach up to 2500 HV, depending on the grain size and the presence of binders.
- Young’s Modulus: The Young’s modulus (measure of stiffness) of tungsten carbide is approximately 530 to 700 GPa, reflecting its high level of rigidity.
- Thermal Conductivity: It has a high thermal conductivity, ranging from 80 to 200 W/(m·K), which helps dissipate heat effectively.
- Thermal Expansion Coefficient: Despite its high melting point, tungsten carbide has a relatively low thermal expansion coefficient, typically around 5.0 × 10^-6 /°C.
- Chemical Stability: Tungsten carbide is highly resistant to corrosion from acids and alkalies, except for hydrofluoric acid and strong oxidizers at high temperatures.
- Fracture Toughness: The fracture toughness of tungsten carbide varies depending on its composition and microstructure but can reach values that make it suitable for demanding applications.
- Synthesis: Tungsten carbide is typically produced through a powder metallurgical process, combining tungsten carbide powder with a binder metal (often cobalt, nickel, or iron) and sintering the mixture at high temperatures.
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Applications: It is extensively used in cutting tools (e.g., drills, milling cutters), mining and construction machinery (e.g., drill bits, crushers), wear parts (e.g., pump seals, valve components), and jewelry due to its hardness and durability.