Method to control dissolution of silicon carbide during fabrication of a ceramic matrix composite
AssigneeRolls-Royce High Temperature Composites Inc.
InventorsNesredin Kedir, Pathikumar Sellappan, Sungbo Shim
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Abstract
A method of controlling dissolution of silicon carbide during melt infiltration to form a ceramic matrix composite includes depositing an interface coating comprising boron nitride on silicon carbide fibers, and depositing a barrier coating comprising silicon carbide on the interface coating. After depositing the barrier coating, a fiber preform comprising the silicon carbide fibers is infiltrated with a melt comprising a silicon-boron alloy that includes boron at a concentration between 0.4 wt. % and 3.3 wt. %. The melt is then cooled to form a ceramic matrix composite.
Claims15
A method of controlling dissolution of silicon carbide during melt infiltration to form a ceramic matrix composite, the method comprising:
- depositing an interface coating comprising boron nitride on silicon carbide fibers;
- depositing a barrier coating comprising silicon carbide on the interface coating;
- after depositing the barrier coating, infiltrating a fiber preform comprising the silicon carbide fibers with a melt comprising a silicon-boron alloy including boron at a concentration between 0.4 wt. % and 3.3 wt. %, wherein the melt does not include carbon, chromium, titanium, vanadium, or molybdenum;
- selecting the concentration of boron within the range to maintain a thickness of the barrier coating after infiltration with the melt that is at least 70% and up to 100% of the thickness of the barrier coating prior to melt infiltration;
- and
- cooling the melt, thereby forming a ceramic matrix composite.
A method of reducing dissolution of silicon carbide during melt infiltration to form a ceramic matrix composite, the method comprising:
- depositing an interface coating comprising boron nitride on silicon carbide fibers;
- depositing a barrier coating comprising silicon carbide on the interface coating;
- and
- after depositing the barrier coating, infiltrating a fiber preform comprising the silicon carbide fibers with a melt at a temperature below a melting temperature (Tm) of silicon, the melt comprising a silicon-boron alloy that does not include carbon, chromium, titanium, vanadium, or molybdenum, with the amount of boron in the silicon-boron alloy selected to control dissolution of the barrier coating such that that a thickness of the barrier coating after infiltration with the melt is at least 70% and up to 100% of the thickness of the barrier coating prior to melt infiltration, and
- cooling the melt, thereby forming a ceramic matrix composite.
Dependencies are inferred from the claim text.