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GLAZED HARD PORCELAIN TITANIUM OXIDE ALUMINIUM OXIDE ALUMINA - ZIRCONIA
ZIRCONIUM OXIDE SILICON CARBIDE SILICON NITRIDE PRODUCTION PROCESSES
  SILICON CARBIDE (SiC)
The product Silicon carbide is a non-oxide material artificially produced in electric kilns at high temperature, two crystalline phases exist: ALPHA and BETA. Our types are all in the ALPHA phase.

 
Properties Excellent resistance to wear, thermal shock and corrosion. Low thermal expansion, high thermal conductivity, high strength at low and high temperatures, good electrical conductor, low friction coefficient.
 
Applications Thanks to the typical high thermal conductivity, silicon carbide thread guides are particularly suitable for highly aggressive yarns and where there are thread guide over heating problems. Low temperature of thread guide drastically reduces problems connected with spin finishes.
In addition, thanks to its good electrical conductivity antistatic thread guides can be produced, to discharge the electrostatic charges, which can form on man-made fibres at high speeds.
 
    Production processes   Dry and isostatic pressing; injection moulding; hot pressing.  
 
Technical data The following table gives physical and mechanical data. Material data are obtained from specimens according to international test specifications. The indicated values can’t be extended to components and parts with different shapes and surface finishings.
Bettini S.r.l. reserves the right to make technical modifications.

BETTINI CERAMICS SILICON CARBIDE (SiC)
MATERIAL CODE   BC-4
COLOUR   Black
SPECIFIC WEIGHT g/cm3 3,10
H20 ABSORPTION % 0
VICKERS HARDNESS (HV, 500g) GPa 26,0
COMPRESSIVE STRENGTH MPa 2200
FLEXURAL STRENGTH MPa 530
YOUNG'S MODULUS (E) GPa 420
FRACTURE TOUGHNESS (Kic) MPa m1/2 4
MAX. SERVICE TEMPERATURE °C 1300
THERMAL CONDUCTIVITY W/ m K 110
THERMAL EXPANSION COEFFICIENT 20°C - 400°C x10-6 / °C 3,8
20°C - 800°C x10-6 / °C 4,4


Bettini also produces infiltrated silicon carbide and hot moulded silicon carbide for mechanical applications (see Bettini technical catalogue).
 
Dimensional tolerances Standard tolerances: up to 10mm: 0.2mm, above 10mm: 2%
Bending deformation: max. 0.5% of part length
Very close tolerances can be reached by grinding and polishing sintered parts, normally up to quality class IT8. Few microns tolerances can be achieved if needed.
 
Surface finishings The sintered products are manufactured with the following surface finishings

Ground Ra from 0,3 to 0,8µm;
Satin Ra ≤ 0,4 µm;
Polished satin Ra up to 0,3 µm;
Diamond-polished Ra ≤ 0,1 µm
 
Some examples of microstructure
Polished,
magnified 250X,
SEM micrograph.
Ra 0.0485 µm
Roughness metre:
Gauss cut off 7*0.8mm,
diamond tip cone 60° 2 micron


The examples reported are indicative only. For further information please contact our
technical staff.
 
Friction coefficient Friction coefficient diagram for material with Ra ≤ 0,4µm


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