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AssigneeThe United States of America as represented by the United States Department of Energy
InventorsDavid P. Stinton, Walter J. Lackey, Robert J. Lauf
Estimating the term…
Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa.sqroot.m which represents a significant increase over that of silicon carbide.
A ceramic structure comprising a ceramic substrate capable of withstanding a temperature of at least about 1,200.degree. C. and -1,500.degree. C. and a ceramic composite coating thereon, said coating comprising a matrix phase of silicon carbide and an intermetallic phase of titanium disilicide uniformly dispersed within said matrix.
A method for fabricating a ceramic structure provided with a ceramic composite coating thereon formed by chemical vapor deposition, comprising the steps of contacting a ceramic substrate capable of withstanding a temperature of at least about 1,200.degree. C.-1,500.degree. C. with the gaseous mixture of methyltrichlorosilane, titanium tetrachloride and the carrier gas of hydrogen, and heating the substrate and gaseous mixture to a temperature sufficiently to thermally decompose the methyltrichlorosilane and the titanium tetrachloride to effect the codeposition of a matrix phase of silicon carbide and a dispersed intermetallic phase of titanium disilicide.
Dependencies are inferred from the claim text.