Other MTO

Silicon Carbide Coatings for Pyrolytic Graphite Substrate

Silicon carbide (SiC) is composed of tetrahedra of carbon and silicon atoms with strong bonds in the crystal lattice. 

 

This produces a very hard and strong material. Silicon carbide is not attacked by any acids or alkalis or molten salts up to 800°C. In air, SiC forms a protective silicon oxide coating at 1200°C and is able to be used up to 1600°C.

The high thermal conductivity coupled with low thermal expansion and high strength gives this material exceptional thermal shock resistance properties.

 

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Key Properties

  • Low density
  • High strength
  • Low thermal expansion
  • High thermal conductivity
  • High hardness
  • High elastic modulus
  • Excellent thermal shock resistance
  • Superior chemical inertness

Engineering Properties*

EngineeringProperties

Heat and Wear-Resistant Materials

Carbon composites are routinely used in airplane brakes where light weight, low wear rate, and temperature resistance are critical.

 

Carbon composites also provide self-lubricating features that promote extended life. For example, a specialized brake pack for the V-22 Osprey aircraft was developed in cooperation with Parker Hannifin using a carbon composite coated with silicon carbide.

 

This brake surface offers exceptional friction performance over a wide temperature range and excellent wear results.

The high thermal conductivity coupled with low thermal expansion and high strength gives this material exceptional thermal shock resistance along with very high friction properties

Carbon Composite SiC Product Applications

  • Couplings
  • Clutches
  • Hoists
  • Winches
  • Brakes
  • Transmissions
  • Mechanical
  • Torque transmitters/limiters

 

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Deposited Shapes

Pyroid® pyrolytic graphite is available as custom free standing as deposited shapes, having diameters up to 18 in. (46 cm) and wall thickness of 0.050 in. (0.127 cm).  Some of the shapes we manufacture are cylindrical tubes, spherical domes, rods, crucibles, trays, and shapes to match your specifications and drawings.

 

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Pyrolytic Graphite for the Glass Industry

Pyroid pyrolytic graphite material is a universal glass-handling material having exceptional heat resistance, strength, and durability with non-absorption characteristics to perform under the most rigorous conditions without damaging the glassware.

 

PyrolyticGraphicGlassIndustry

The material offers:

  • Exceptionally high purity > 99.999% 

    Benefit: No marring of glass surfaces 
  • Exceptional high oxidation resistance

    Benefit: Extremely long tool life
  • High thermal conductivity

    Benefit: Exception tolerance to thermal shock
    Ideal for all types of glass including:
  • Soda-lime
  • Borosilicate
  • Lead Glass
  • Aluminosilicate glass
  • Fused silica

    Found in such applications as:
  • Fine stemware
  • Pharmaceutical packaging
  • Microscopy
  • LED
  • Photovoltaic
  • Specialty glass tubing

 

MirrorSurfaces

Pyroid PG SN and CN is ideal material for tools for manufacturing of all mirror surfaces

Analytical Instrument Accessories

Low metallic impurities (< 5 ppm total metallic ash) make Pyrolytic Graphite ideal material for manufacturing atomic absorption spectrograph planchettes, crucibles for plasma vaporization, and sputter-coating scanning electron microscope samples requiring a conductive, non-metallic coating and bio-compatible material requirement.

Rocket Nozzles


RocketNozzles

 

Pyroid® pyrolytic graphite has a long history of successful operation as a material of choice for solid propellant rocket exhaust nozzles, throat inserts, and guide vanes.

Pyrolytic graphite is an excellent thermal insulator in the direction normal to the deposition layer planes. The material offers the lowest known erosion resistance of any material operating under severe conditions up to flame temperatures of 3,600 oC (6,500 oF).


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The best erosion resistance is achieved by exposing the pyrolytic graphite layer plane to the hot discharge gases.  When used in this orientation for best erosion resistance, the inherent insulating properties in the material leads to a rapid rise in nozzle surface temperature and a significant reduction in the heat leakage along the nozzle body, promoting a near stoichiometric combustion process.

Pyroid® pyrolytic graphite is also available as a nozzle throat insert, compatible with most composite  

 

HARM

AGM-88 High-Speed Anti-radiation Missile (HARM)
(Courtesy of Raytheon Corp.)

materials. These inserts are orientated to better withstand mechanical erosion of the hot exhaust gases while promoting rapid thermal transfer away from the hot zone.

Because the throat geometry remains constant throughout the propellant burn, this promotes a more predictable burn of the propellant grain, even under high acceleration loads.

Studies have shown that for low temperature propellants, the erosion of Pyroid® pyrolytic graphite is negligible. Environmental firing test results also indicate pyrolytic graphite nozzles and inserts are relatively insensitive to a wide range of reactive propellant combinations.

These advantages, coupled with Pyroid® pyrolytic graphite's high strength, high thermal conductivity, low thermal expansion, and low weight are keys to extending the range of today's advanced rocket technology. 

Sputtering Targets

The ultrahigh purity (< 5 ppm ash) and high density (2.2 g/cc) of PG material results in sputtered carbon films showing enhanced mechanical and tribochemical wear critical to the protection of rigid disks.

 

SputteringTargets