Oxidation resistant fiber reinforced composite article

Claim 2

A fiber reinforced composite article, comprising: from about 20 volume percent to about 60 volume percent silicon carbide fibers, and from about 40 volume percent to about 80 volume percent glass-ceramic matrix, said glass-ceramic matrix having from about 60 weight percent to about 75 weight percent SiO 2 , from about 15 weight percent to about 25 weight percent Al 2 O 3 , from about 1.5 weight percent to about 5 weight percent Li 2 O, from about 1 weight percent to about 5 weight percent MgO, up to about 3 weight percent ZnO 2 , up to about 3 weight percent As 2 O 3 , and from about 2 weight percent to about 5 weight percent B 2 O 3 said composite article exhibiting both high flexural strength at temperatures of up to about 1000° C. and oxidative stability at temperatures above about 450° C. in an oxidizing environment.

Claim 3

A fiber reinforced composite article, comprising: from about 20 volume percent to about 60 volume percent silicon carbide fibers, and from about 40 volume percent to about 80 volume percent glass-ceramic matrix, said glass-ceramic matrix comprising from about 60 weight percent to about 75 weight percent SiO 2 , from about 15 weight percent to about 25 weight percent Al 2 O 3 , from about 1.5 weight percent to about 5 weight percent Li 2 O, from about 1 weight percent to about 5 weight percent MgO, from about 1 weight percent to about 3 weight percent ZrO 2 , from about 0.4 weight percent to about 2 weight percent Na 2 O, from about 0.05 weight percent to about 0.5 weight percent K 2 O, from about 0.5 weight percent to about 3 weight percent As 2 O 3 , up to about 2 weight percent ZnO, up to about 2 weight percent BaO, up to about 1 weight percent Nd 2 O 3 , and from about 1 weight percent to about 5 weight percent B 2 O 3 where the combined amount of ZnO, BaO, Na 2 O, K 2 O and As 2 O 3 is between about 0.2 weight percent and about 3 weight percent, and said composite article exhibits both high flexural strength at temperatures of up to about 1000° C. and oxidative stability at temperatures of above about 450° C. in an oxidizing environment.

Claim 4

A fiber reinforced composite article, comprising: from about 20 volume percent to about 60 volume percent silicon carbide fibers, and from about 40 volume percent to about 80 volume percent glass-ceramic matrix, said glass-ceramic matrix comprising from about 60 weight percent to about 75 weight percent SiO 2 , from about 15 weight percent to about 25 weight percent Al 2 O 3 , from about 1.5 weight percent to about 5 weight percent Li 2 O, from about 1 weight percent to about 5 weight percent MgO, from about 1 weight percent to about 3 weight percent ZrO 2 , from about 0.4 weight percent to about 2 weight percent Na 2 O, from about 0.05 weight percent to about 0.5 weight percent K 2 O, from about 0.5 weight percent to about 3 weight percent As 2 O 3 , up to about 2 weight percent ZnO, up to about 2 weight percent BaO, up to about 1 weight percent Nd 2 O 3 , and from about 1 weight percent to about 5 weight percent B 2 O 3 where the combined amount of ZnO, BaO, Na 2 O, K 2 O and As 2 O 3 is between about 0.2 weight percent and about 3 weight percent, and said composite article exhibits both high flexural strength at temperatures of up to about 1000° C. and oxidative stability at temperatures of above about 450° C. in an oxidizing environment.