Graphite Crucibles

Graphite Crucibles offer a range of properties that make them the top choice for high-temperature applications, particularly in metal smelting and foundry work. Here are the key material properties and specifications that define the performance of these crucibles:

1. Thermal Conductivity
   • Graphite crucibles exhibit excellent thermal conductivity, ensuring uniform heat distribution. This property reduces hot spots and ensures even melting, making them highly efficient for metals like gold, copper, and aluminum.
   • Thermal conductivity can reach values of up to 100 W/m·K, which is superior compared to traditional refractory materials.
2. High-Temperature Resistance
   • Graphite crucibles are capable of withstanding extremely high temperatures, up to 1700°C in inert atmospheres or vacuum conditions. This allows them to maintain structural integrity in demanding environments without degrading.
   • These crucibles remain stable and resistant to deformation under intense heat.
3. Low Coefficient of Thermal Expansion
   • Graphite materials have a low coefficient of thermal expansion (as low as 4.9 x 10^-6 /°C), reducing the risk of cracking or thermal shock when exposed to rapid temperature changes.
   • This feature makes graphite crucibles particularly suitable for processes that involve repeated heating and cooling cycles.
4. Corrosion Resistance
   • Graphite is chemically inert and offers high resistance to most acids, alkalis, and other corrosive agents, especially in reducing or neutral atmospheres. This makes graphite crucibles ideal for aggressive chemical environments in metal casting or refining.
   • The material's resistance to oxidation can be further enhanced by coatings or special treatments, ensuring prolonged service life.
5. Electrical Conductivity
   • As a good conductor of electricity, graphite materials are suitable for induction heating applications. The high electrical conductivity enables efficient coupling with induction systems, ensuring rapid and uniform heating.
   • This property is particularly useful in processes requiring induction heater crucibles, enhancing operational efficiency in industries like foundry work or metallurgy.
6. Purity and Material Composition
   • High-purity carbon graphite crucibles (up to 99.9% purity) are essential for applications where metal contamination must be avoided, such as in the production of precious metals or advanced ceramics.
   • Silicon carbide graphite crucibles combine the properties of both graphite and silicon carbide, offering enhanced mechanical strength, oxidation resistance, and a higher melting point, suitable for extreme operating conditions.
7. Durability and Longevity
   • Isostatically pressed graphite crucibles are manufactured to have uniform density and strength, resulting in longer lifespans and reduced material failure during high-temperature operations. These crucibles are also more resistant to erosion and mechanical damage.

8. Chemical Composition:

   • Carbon (C): 20-30%
   • Silicon Carbide (SiC): 50-60%
   • Alumina (Al2O3): 3-5%
   • Others: 3-5%
9. Customizable Sizes and Shapes
   • Our graphite crucibles are available in a wide variety of sizes and configurations. From small graphite crucibles (suitable for lab-scale metal testing) to large crucibles designed for industrial-scale smelting, we offer tailored solutions for every application.
   • Graphite-lined crucibles and crucibles with pour spouts can also be customized to specific casting requirements, ensuring convenience and efficiency in metal handling.