Zirconium carbide (ZrC) is a refractory ceramic compound known for its exceptional hardness, high melting point, and excellent chemical stability. Some key parameters that define the properties and characteristics of zirconium carbide include:
- Chemical Formula: ZrC
- Molecular Weight: Approximately 103.22 g/mol
- Appearance: Zirconium carbide appears as a grayish-black, crystalline powder.
- Density: 5.83 g/cm³. This high density contributes to its use in applications requiring wear resistance.
- Melting Point: ZrC has an extremely high melting point, around 3530°C (6386°F), making it suitable for high-temperature applications.
- Thermal Conductivity: It exhibits good thermal conductivity, typically ranging from 20 to 30 W/(m·K) at room temperature. This property is beneficial for heat sink applications.
- Hardness: Zirconium carbide is very hard, with a Vickers hardness of approximately 2200 Hv, which is comparable to tungsten carbide and much harder than most steels.
- Chemical Stability: ZrC is highly resistant to corrosion from most acids, alkalis, and salt solutions, except for hydrofluoric acid and hot concentrated sulfuric acid.
- Mechanical Properties: Besides its hardness, ZrC also demonstrates high tensile strength and fracture toughness, important for its use in cutting tools and wear-resistant coatings.
- Oxidation Resistance: At elevated temperatures, ZrC forms a protective oxide layer (zirconia, ZrO₂) which enhances its oxidation resistance up to about 1800°C.
- Electrical Conductivity: Zirconium carbide is electrically conductive, although its conductivity is lower compared to metals.
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Grain Size: The grain size can significantly affect the material’s properties. Finer grain sizes generally result in increased hardness and improved fracture toughness.
These parameters make zirconium carbide suitable for various applications such as cutting tools, wear-resistant coatings, nuclear reactor fuel elements, and high-temperature structural materials in aerospace and defense industries.
