Isostatic Graphite Properties

HHGRAPHITE as a leading graphite product manufacturer in China, we are proud to offer a wide range of graphite products, including those made using vibration, mold pressing, extrusion, and isostatic pressing techniques. In this article, we focus on isostatic graphite, delving into its unique qualities, differences from extruded graphite, production process, features, density, specifications, and applications.

1. Difference Between Extruded Graphite and Isostatic Graphite

Extruded Graphite:

Production Process: Extruded graphite is produced by pushing graphite material through a die, creating a shape with a uniform cross-section.

Properties: It has anisotropic properties, meaning its strength and conductivity vary in different directions. This makes it suitable for applications where directional properties are advantageous.

Applications: Commonly used in electrodes, furnace parts, and mechanical seals, where specific directional properties are beneficial.

Isostatic Graphite:

Production Process: Isostatic graphite is created by applying equal pressure from all directions to graphite powder within a mold, resulting in isotropic properties.

Properties: It offers uniform properties in all directions, including consistent strength and conductivity. This makes it ideal for applications demanding high reliability and performance.

Applications: Utilized in semiconductor manufacturing, aerospace components, and nuclear reactors, where uniform properties are crucial.

Click to view the graphite products we offer

2. Isostatic Graphite Production Process

The production of isostatic graphite involves several critical steps to ensure the highest quality and uniformity:

Graphite Powder Preparation: High-purity graphite powder is carefully selected and mixed with a binding agent to form a homogeneous blend.

Click to view the graphite products we offer

Molding: The mixture is placed into a flexible rubber mold, which is then sealed and placed in a high-pressure chamber.

Isostatic Pressing: The mold is subjected to equal pressure from all sides using a hydraulic press. This pressure typically ranges from 100 to 200 MPa, ensuring the graphite powder compacts uniformly without internal stresses or defects.

Click to view the graphite products we offer

Baking and Carbonization: The pressed material is removed from the mold and heated in a furnace to remove the binder, converting the mixture into a solid graphite block through carbonization.

Click to view the graphite products we offer

Graphitization: The block is subjected to extremely high temperatures (around 3,000°C) in a controlled environment to align the carbon atoms and form the final graphite structure.

Click to view the graphite products we offer

Machining and Finishing: The resulting graphite block is machined to the desired specifications, ensuring precise dimensions and surface finish.

Click to view the graphite products we offer

3. Features of Isostatic Graphite

Isostatic graphite stands out due to its remarkable properties:

Uniformity: The isotropic nature ensures consistent mechanical, thermal, and electrical properties in all directions, making it highly reliable for demanding applications.

High Strength: It possesses excellent mechanical strength, allowing it to withstand high-stress environments without degradation.

Thermal Stability: Isostatic graphite can endure extreme temperatures without losing its structural integrity, making it suitable for high-temperature applications.

Electrical Conductivity: Its superior electrical conductivity makes it ideal for use in electrical applications, including electrodes and connectors.

Chemical Resistance: The material is resistant to most chemicals, ensuring longevity and performance in corrosive environments.

Density of Isostatic Graphite

Isostatic graphite is known for its high density, typically ranging between 1.75 and 1.90 g/cm³. This high density is achieved through the isostatic pressing process, which compacts the graphite powder uniformly, eliminating voids and ensuring a solid, defect-free structure. The high density contributes to the material’s strength, thermal stability, and electrical conductivity.

Contact us for customized isostatic graphite service

4. Specifications of Isostatic Graphite

Our isostatic graphite products are available in a variety of specifications to meet diverse industrial requirements:

Density: 1.75 - 1.90 g/cm³

Flexural Strength: 30 - 50 MPa

Compressive Strength: 80 - 120 MPa

Thermal Conductivity: 100 - 140 W/m·K

Coefficient of Thermal Expansion: (2.5 - 4.5) × 10⁻⁶ /°C

Electrical Resistivity: 8 - 12 μΩ·m

Porosity: < 0.5%

These specifications can be tailored to specific applications, ensuring optimal performance for our clients’ needs.

Contact us for customized isostatic graphite service

5. Applications of Isostatic Graphite

Isostatic graphite’s unique properties make it suitable for a wide range of applications across various industries:

Semiconductor Manufacturing: Used in the production of silicon wafers, solar cells, and other semiconductor components due to its high purity and uniformity.

Aerospace: Essential for manufacturing components that require high strength and thermal stability, such as rocket nozzles and satellite parts.

Automotive Industry: Applied in brake linings and clutch facings, where high strength and thermal conductivity are crucial for safety and performance.

Electrical Applications: Ideal for electrodes, connectors, and other electrical components due to its excellent electrical conductivity and stability.

Click to view Haihan's customized isostatic graphite solutions for different industries

6. Conclusion

Isostatic graphite offers unmatched performance and versatility, making it an ideal choice for industries requiring high-purity, high-strength, and reliable materials. With its superior uniformity, thermal stability, and electrical conductivity, isostatic graphite continues to set the standard for high-performance applications.

As a trusted graphite product manufacturer in China, we are committed to providing top-quality isostatic graphite products that meet the diverse needs of our clients. Contact us today to learn more about how our isostatic graphite solutions can enhance your industrial applications.