Technical Ceramics. Cemented Carbides. Composite Materials

Ceramic Matrix Composites (CMC)


Ultrahard structural ceramics are successfully used in tribological applications, including wear-resistant friction pairs of slide bearing operating in severe conditions that involve aggressive media, presence of abrasive inclusions, and high temperatures. Nonetheless, this class of materials has a number of limitations, including:

  • low impact resistance
  • brittle fracture
  • part size and shape limitations
  • defect size effect
  • limited load level during sliding.

One of the major possible approaches to improve the above limitations is the development of ceramic matrix composite (CMC) materials. CMC is a new class of ceramic-based materials that contain ceramic matrix reinforced by carbon or ceramic fiber.

CMC materials combine the best advantages of the engineering ceramics and fibre-reinforced composites: high hardness and strength, excellent wear and corrosion resistance, moreover, they feature significantly improved fracture toughness and graceful fracture behavior. This combination of properties makes CMC a material of choice for processing of large-sized parts with greater reliability than is ever possible with conventional structural ceramics.


  • Large and thin-walled inserts for tribological assemblies (slide bearings for centrifugal ESP and rotary-vortex pumps) working in sever conditions involving aggressive and abrasive media, elevated temperatures and mechanical loading;
  • Face seals, valving parts, actuators for producing and processing machinery for mining, petrochemical and gas sectors

CMC are the enabling materials for the designers of large and high-capacity pumping equipment; offering unique capabilities for controlling slide bearing performance. By tailoring such parameters as reinforcement architecture, matrix/reinforcement ratio, and interfaces one could design tribotechnical assemblies that make effective use of counterbodies based on ultrahard ceramics, or hardened steels, etc.

Physical and mechanical parameters

Material Density, g/cm³ Porosity, not more than %
Transverse rupture strength, MPa Impact toughness, kJ•mˆ(-2) Young modulus, GPa Content free of Si, %
Type А 2,0 - 2,5 1,0 180 - 350 7 - 14 280 - 350 3,0 - 6,0
Type Б 1,7 - 2,0 9,0 90 - 350 10 - 20 250 - 280 1,0 - 3,0

Parameter Material
CMC type А SiSiC
Density, g/cm³ 2,00 - 2,50 3,05 - 3,11
Transverse rupture strength, MPa 180 - 350 300 - 450
The nature of the destruction

Копия KrivayaCMC.jpg

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Fracture toughness, MPa m½ 15,0 - 20,0 3,5 - 4,5