Methods of forming siAlON in carbon/carbon composites
A method of making a carbon-carbon composite may comprise forming a Silicon-Aluminum-Oxygen-Nitrogen (SiAlON) precursor suspension and infiltrating a fibrous preform with the SiAlON precursor suspension. A SiAlON forming heating treatment may be performed on the fibrous preform to form SiAlON particles. The fibrous preform may be densified using chemical vapor infiltration to form a densified fibrous preform.
1 . A method of making a carbon-carbon composite, comprising:
forming a Silicon-Aluminum-Oxygen-Nitrogen (SiAlON) precursor suspension by combining an aluminum source, a positively charged silicon source, and a carrier fluid;
infiltrating a fibrous preform with the SiAlON precursor suspension;
performing a SiAlON forming heating treatment on the fibrous preform to form SiAlON particles; and
densifying the fibrous preform by chemical vapor infiltration (CVI) to form a densified fibrous preform.
2 . The method of claim 1 , wherein the aluminum source comprises alumina (Al 2 O 3 ) and is positively charged.
3 . The method of claim 2 , wherein the silicon source comprises silica (SiO 2 ) having a thin film of positively charged aluminum oxide.
4 . The method of claim 3 , wherein the SiAlON precursor suspension further comprises carbon black.
5 . The method of claim 1 , wherein the silicon source comprises colloidal silica (SiO 2 ) and the aluminum source comprises colloidal alumina (Al 2 O 3 ).
6 . The method of claim 1 , wherein performing the SiAlON forming heating treatment on the fibrous preform comprises heating the fibrous preform in a presence of nitrogen gas and at a temperature of between 1100° C. and 1600° C.
7 . A method of making a carbon-carbon composite, comprising:
partially densifying a fibrous preform;
infiltrating the fibrous preform with a first Silicon-Aluminum-Oxygen-Nitrogen (SiAlON) precursor suspension having an aluminum source, a positively charged silicon source, and a carrier fluid;
performing a first SiAlON forming heating treatment on the fibrous preform; and
densifying the fibrous preform to form a fully densified fibrous preform.
8 . The method of claim 7 , further comprising:
performing a first heat treatment on the fibrous preform prior to partially densifying the fibrous preform; and
performing a second treatment on the fully densified fibrous preform.
9 . The method of claim 7 , further comprising infiltrating the fibrous preform with a second SiAlON precursor suspension prior to partially densifying the fibrous preform.
10 . The method of claim 9 , further comprising performing a second SiAlON forming heating treatment on the fibrous preform after infiltrating the fibrous preform with the second SiAlON precursor suspension and prior to partially densifying the fibrous preform.
11 . The method of claim 7 , further comprising forming the first SiAlON precursor suspension by combining the aluminum source, the positively charged silicon source, and a carbon source.
12 . The method of claim 11 , wherein the silicon source comprises silica (SiO 2 ) having a thin film of positively charged aluminum oxide.
13 . The method of claim 12 , wherein the silicon source comprises colloidal silica (SiO 2 ), the aluminum source comprises colloidal alumina (Al 2 O 3 ), and the carbon source comprises carbon black.