Huahao Sealing · Carbon Graphite Components
Isostatic graphite is a high-purity graphite formed by cold isostatic pressing (CIP), featuring high isotropy and uniform structure. Huahao Sealing supplies isostatic graphite blanks and precision-machined parts with purity above 99.99%, density 1.75-1.85 g/cm³ and isotropy below 5%, for semiconductor, photovoltaic, nuclear and high-precision sealing applications.
| Density | 1.75 – 1.85 g/cm³ |
| Purity | > 99.99% carbon |
| Isotropy | < 5% (CTE variation) |
| Temperature | -200°C ~ 500°C (inert atmosphere 2800°C) |
| Compressive Strength | 120 – 200 MPa |
| Shore Hardness | 55 – 75 HS |
| Grain Size | 10 – 20 μm (fine-grain) |
| Ash Content | < 100 ppm |
High purity — carbon content above 99.99%, ash below 100 ppm, meeting semiconductor and photovoltaic purity requirements
Isotropy — isostatic forming ensures uniform properties in all directions, anisotropy below 5%, no deformation during precision machining
Uniform structure — fine-grain structure (10-20 μm), consistent cross-sectional properties for high-precision seals
High machinability — moderate hardness (55-75 HS) allows complex geometries and micron-level tolerances
Ultra-high temperature — up to 2800°C in inert atmosphere, 2000°C in vacuum
Semiconductor manufacturing — crystal growth furnace heaters, crucibles, heat shields
Photovoltaic industry — monocrystalline silicon pulling furnace graphite components
High-temperature vacuum furnaces — heating elements, radiation shields, furnace beds
Nuclear industry — reactor graphite reflectors and moderators
High-precision sealing — EDM-machined seals, precision molds
| Grade Code | Temperature | Notes |
|---|---|---|
| IG-11 | 2800°C | General isostatic graphite, semiconductor grade |
| IG-430 | 2800°C | High-density isostatic graphite, wear-resistant |
Isostatic graphite is formed by CIP (cold isostatic pressing) with uniform pressure from all directions, achieving isotropy below 5% with uniform structure and high purity. Standard molded graphite is unidirectionally pressed, with high anisotropy and significant directional property variation, unsuitable for high-precision and high-purity applications.
Yes. Isostatic graphite has purity above 99.99% and ash below 100 ppm, meeting the semiconductor industry's strict material purity requirements. It is widely used for crystal growth furnace heaters, crucibles and heat shields.
