Glassy Carbon Crucibles

Glassy carbon is a non-graphitizable carbon that has both the glassy and ceramic properties of graphite. Carbon comes in many forms. The carbon we are familiar with is diamond and graphite, which are two very different forms. Unlike graphite, glassy carbon has a microstructure associated with fullerenes, giving it a variety of unique material properties.

Glassy carbon is a completely amorphous material with no crystallinity. X-ray diffraction showed only "amorphous halos". When glassy carbon breaks, it exhibits the characteristic fracture of glassy materials. It is precisely because of a series of properties of glassy carbon that it can be made into devices of various shapes and become a new type of material in the field of research and production.

Main features：

High temperature resistant in inert gas or vacuum up to 3000°C * Extremely corrosion resistant * High purity * Impermeable to gases and liquids, no open pores

Not wetted by the melt * High hardness and strength * Isotropic physical and chemical properties * High surface quality without particle generation

low thermal expansion * excellent thermal shock resistance * low density * good electrical conductivity

Biocompatibility

typical application

High temperature technology and research

Glassy carbon SIGRADUR® is resistant to high temperatures in inert gas or vacuum up to 3000°C. Unlike all other ceramic and metallic high temperature materials, the strength of glassy carbon increases and the temperature rises to 2700k. Glassy carbon at 2700k is twice as strong as room temperature. Compared to ceramic and metallic materials, glassy carbon is also not embrittled at high temperatures. At the same time, compared with most ceramic and metal materials, glassy carbon has extremely high thermal shock resistance;

Chemical Analysis and Chemical Reactions

Compared to conventional equipment made of platinum, gold and other corrosion-resistant metals, special ceramics and fluoroplastics, glassy carbon is resistant to all wet decomposers, has no memory effect (uncontrolled adsorption and desorption of elements), and analyzes samples without Pollution, acid and alkali melting resistance, non-porous glass surface and other characteristics, suitable for chemical analysis;

Dental technology

The glassy carbon crucible eliminates the shortcomings of ceramic crucibles such as low thermal conductivity, high adhesion of precious metal melts, and the need for molten salt. Using glassy carbon crucibles for melting allows for reduced heating and melting times. At the same time, the melt can flow freely without wetting the crucible wall, so that the appearance of the obtained casting is uniform and neat;

Semiconductor

High purity, extreme corrosion resistance, no particle generation, electrical conductivity and good mechanical properties make glassy carbon an ideal material for semiconductor production. Glassy carbon crucibles and vessels are used for the area melting of semiconductor components, the synthesis of gallium arsenide, and the growth of single crystals by the Bridgman or Czochralski methods.

Medical technology

Good mechanical properties in low density, high purity and biocompatibility, high X-ray transmittance make glassy carbon have good application prospects in the medical field;

Metallurgy, Ultrapure Materials

High temperature resistance and very high surface quality, no contamination by foreign elements, no traces of carbon in the molten mass due to hardness and wear resistance. Metal melts that do not form carbides have no wetting effect on glassy carbon crucibles;

x-ray technology

Due to the low atomic number of carbon, X-ray transparency is high. This is beneficial for many applications such as x-rays for synchrotron beamlines

Line windows or masks for x-ray lithography.

Glass industry

Not wetted by molten glass. Due to its hard and smooth surface, glassy carbon does not produce any contamination-causing particles like other carbon materials. Smooth surface, low thermal conductivity and low thermal expansion.