US5164341A — Fiber reinforced ceramic matrix composites exhibi…

Claim 1

Independent Claim 235 words

A fiber-reinforced glass-ceramic matrix composite article exhibiting improved high-temperature strength and toughness having a matrix consisting essentially of an alkaline earth aluminosilicate glass-ceramic matrix in which are disposed reinforcing inorganic fibers having a protective coating thereon, wherein: the inorganic fibers consist essentially of silicon carbide fibers; the inorganic fibers are coated with vapor deposited boron nitride; and the alkaline earth aluminosilicate glass-ceramic matrix is a glass-ceramic selected from the group consisting of: I. glass-ceramics wherein the predominant crystal phase is selected from the group of triclinic anorthite (CaO,SrO·Al 2 O 3 ·2SiO 2 ) and its pseudo-binaries with mullite (3Al 2 O 3 ·SiO 2 ), cordierite (2MgO·2Al 2 O 3 ·5SiO 2 ), barium osumilite (BaO·2MgO·3Al 2 O 3 ·SiO 2 ), albite solid solution (Na 2 O·Al 2 O 3 ·6SiO 2 ), Al 2 O 3 , SiO 2 , CaO·SiO 2 , and gehlenite (2CaO·Al 2 O 3 ·SiO 2 ); and II. internally nucleated glass-ceramics wherein the predominant crystal phase consists essentially of triclinic anorthite (CaO,SrO·Al 2 O 3 ·SiO 2 ) and at least one of mullite and α-alumina, the alumina content of the glass-ceramic being from 10-50 mole percent in excess of that of stoichiometric triclinic anorthite, said composite article exhibiting, when tested for flexural strength at 1000° C., an ultimate strength in excess of 58 ksi and a strain at flexural failure of at least about 0.5%.

Claim 2

Dependent Claim 235 words

A fiber-reinforced glass-ceramic matrix composite article exhibiting improved high-temperature strength and toughness having a matrix consisting essentially of an alkaline earth aluminosilicate glass-ceramic matrix in which are disposed reinforcing inorganic fibers having a protective coating thereon, wherein: the inorganic fibers consist essentially of silicon carbide fibers; the inorganic fibers are coated with vapor deposited boron nitride; and the alkaline earth aluminosilicate glass-ceramic matrix is a glass-ceramic selected from the group consisting of: I. glass-ceramics wherein the predominant crystal phase is selected from the group of triclinic anorthite (CaO,SrO·Al 2 O 3 ·2SiO 2 ) and its pseudo-binaries with mullite (3Al 2 O 3 ·SiO 2 ), cordierite (2MgO·2Al 2 O 3 ·5SiO 2 ), barium osumilite (BaO·2MgO·3Al 2 O 3 ·SiO 2 ), albite solid solution (Na 2 O·Al 2 O 3 ·6SiO 2 ), Al 2 O 3 , SiO 2 , CaO·SiO 2 , and gehlenite (2CaO·Al 2 O 3 ·SiO 2 ); and II. internally nucleated glass-ceramics wherein the predominant crystal phase consists essentially of triclinic anorthite (CaO,SrO·Al 2 O 3 ·SiO 2 ) and at least one of mullite and α-alumina, the alumina content of the glass-ceramic being from 10-50 mole percent in excess of that of stoichiometric triclinic anorthite, said composite article exhibiting, when tested for flexural strength at 1000° C., an ultimate strength in excess of 58 ksi and a strain at flexural failure of at least about 0.5%.

Claim 3

Dependent Claim 87 words

A fiber-reinforced glass-ceramic matrix composite article in accordance with claim 1 wherein the matrix has a composition consisting essentially, in weight percent on the oxide basis, of about 0-25% CaO, 0-30% SrO, 10-30% CaO+SrO, 25-38% Al 2 O 3 , 35-60% SiO 2 , O-25% BaO, 0-15% MgO, 0-4% Na 2 O, 0-6% K 2 O, 0-12% TiO 2 , 0-15% ZrO 2 , 0-3% As 2 O 3 %, and 0-30% total of BaO+MgO+Na 2 O+K 2 O+TiO 2 +ZrO 2 +As 2 O 3 .

Claim 4

Dependent Claim 127 words

A fiber-reinforced glass-ceramic matrix composite article in accordance with claim 1 wherein the matrix has a composition, in weight percent on the oxide basis, of about 16-20% CaO, 38.5-46% Al 2 O 3 , 35-42% SiO 2 , 0.25-1.5% As 2 O 3 , and up to 10% total of at least one nucleating agent selected in the indicated proportion from the group consisting of 0.1-3% Cr 2 O 3 , 0.25-3% HfO 2 , 2-5% MoO 3 , 0.25-3% Nb 2 O 5 , 0.25-3% Ta 2 O 5 , 0.25-3% WO 3 , and 1-10% ZrO 2 , and wherein the proportion of Al 2 O 3 is 5-50 mole percent in excess of the proportion of Al 2 O 3 in stoichiometric triclinic anorthite.

Claim 5

Dependent Claim 239 words

In the process for making a ceramic matrix composite article wherein inorganic reinforcing fibers are embedded in a ceramic matrix material and the fibers and ceramic matrix material are thereafter consolidated together into a dense ceramic matrix composite article by the application of heat and pressure thereto, the improvement wherein: (i) the inorganic fibers consist essentially of silicon carbide fibers; (ii) the ceramic matrix material is an alkaline earth aluminosilicate glass-ceramic matrix is a glass-ceramic selected from the group consisting of: I. glass-ceramics wherein the predominant crystal phase is selected from the group of triclinic anorthite (CaO,SrO·Al 2 O 3 ·2SiO 2 ) and its pseudo-binaries with mullite (3Al 2 O 3 ·SiO 2 ), cordierite (2MgO·2Al 2 O 3 ·5SiO 2 ), barium osumilite (BaO·2MgO·3Al 2 O 3 ·9SiO 2 ), albite solid solution (Na 2 O·Al 2 O 3 ·6SiO 2 ), Al 2 O 3 , SiO 2 , CaO·SiO 2 , and gehlenite (2CaO·Al 2 O 3 ·SiO 2 ); and II. internally nucleated glass-ceramics wherein the predominant crystal phase consists essentially of triclinic anorthite (CaO,SrO·Al 2 O 3 ·SiO 2 ) and at least one of mullite and α-alumina, the alumina content of the glass-ceramic being from 10-50 mole percent in excess of that of stoichiometric triclinic anorthite; and (iii) prior to the step of embedding the fibers in the matrix material the fibers are first provided with a vapor-deposited boron nitride surface coating.

Claim 6

Dependent Claim 239 words

In the process for making a ceramic matrix composite article wherein inorganic reinforcing fibers are embedded in a ceramic matrix material and the fibers and ceramic matrix material are thereafter consolidated together into a dense ceramic matrix composite article by the application of heat and pressure thereto, the improvement wherein: (i) the inorganic fibers consist essentially of silicon carbide fibers; (ii) the ceramic matrix material is an alkaline earth aluminosilicate glass-ceramic matrix is a glass-ceramic selected from the group consisting of: I. glass-ceramics wherein the predominant crystal phase is selected from the group of triclinic anorthite (CaO,SrO·Al 2 O 3 ·2SiO 2 ) and its pseudo-binaries with mullite (3Al 2 O 3 ·SiO 2 ), cordierite (2MgO·2Al 2 O 3 ·5SiO 2 ), barium osumilite (BaO·2MgO·3Al 2 O 3 ·9SiO 2 ), albite solid solution (Na 2 O·Al 2 O 3 ·6SiO 2 ), Al 2 O 3 , SiO 2 , CaO·SiO 2 , and gehlenite (2CaO·Al 2 O 3 ·SiO 2 ); and II. internally nucleated glass-ceramics wherein the predominant crystal phase consists essentially of triclinic anorthite (CaO,SrO·Al 2 O 3 ·SiO 2 ) and at least one of mullite and α-alumina, the alumina content of the glass-ceramic being from 10-50 mole percent in excess of that of stoichiometric triclinic anorthite; and (iii) prior to the step of embedding the fibers in the matrix material the fibers are first provided with a vapor-deposited boron nitride surface coating.

Claim 7

Dependent Claim 45 words

A method in accordance with claim 4 wherein the fibers and matrix material are consolidated to a dense ceramic matrix composite article by hot pressing to a temperature in the range of about 1200°-1360° C. at a pressure in the range of about 1500-3000 psi.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-11-17	1996-05-18	1996-11-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-11-17	2000-05-18	2000-11-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-11-17	2004-05-18	2004-11-17	$7700.00	Window Closed / Lapsed

Fiber reinforced ceramic matrix composites exhibiting improved high-temperature strength

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