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LITHOEN

Manufacturing process

Chemical vapour infiltration

Also known as CVI, chemical vapor infiltration

A process in which precursor gases diffuse into a porous fibre preform and decompose to deposit the matrix inside it. It is gentle on fibres but slow, and leaves residual porosity.

Classification

matrix families
CERAMIC, CARBON

How this record is known

4
Settled consensus
Cited as the accepted position of the discipline.

4 of 4 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

EstablishedLow-damage densification of C/C and CMC preforms, including complex shapes.

Chemical vapour infiltration operates at lower temperature and pressure than liquid routes, which keeps residual stress low and avoids damaging carbon and ceramic fibres, and it suits complex shapes; it was originally used to make carbon/carbon composites and is used for ceramic-matrix composites with matrices of SiC, Si3N4, carbon, B4C, TiC and Al2O3.

Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown

Evidence: Ruize 2025 Peer-reviewed; Bisma 2022 Peer-reviewed

Established1,000–2,000 degC

The original use of chemical vapour infiltration, to make carbon/carbon composites, deposited the carbon matrix by pyrolysis of methane at 1000–2000 °C.

  • conditions: Methane pyrolysis in the original chemical vapour infiltration route for carbon/carbon composites.

Evidence support: Supported by the cited evidence one source

Evidence: Bisma 2022 Peer-reviewed

EstablishedSlow, costly, pore blockage and residual porosity.

Chemical vapour infiltration uses precursors inefficiently, so cycles are long and costly; deposition near the surface blocks pores, causing density gradients and requiring repeated cycles; and porosity remains in the deposited matrix, which in SiC/SiC has been filled by subsequent slurry and melt-infiltration steps.

Evidence support: Supported by the cited evidence 3 sources, multiple sources, independence unknown

Evidence: Ruize 2025 Peer-reviewed; Bisma 2022 Peer-reviewed; A. 2002 Primary authority

EstablishedPrecursor gases diffuse into a porous preform and decompose to deposit the matrix.

Chemical vapour infiltration, an extension of chemical vapour deposition, infiltrates precursor gases through the pores of a fibre preform, where they decompose thermally and deposit the matrix inside it; it is used both for whole matrices and for thin fibre coatings such as boron nitride interphases.

Evidence support: Supported by the cited evidence 3 sources, multiple sources, independence unknown

Evidence: Ruize 2025 Peer-reviewed; Bisma 2022 Peer-reviewed; A. 2002 Primary authority

In the knowledge graph

Record last updated 2026-10-30. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.