Patent ID: 6254975
Filing Date: 2001-07-03
Classification: C04B,Y10T

Abstract:
A ceramic composite, comprising:a) 30 to 60% by volume of C-fibers;b) 10 to 55% by volume of a matrix made of SiC and C, wherein the weight ratio SiC:C is in the range of between 20:1 and 2:1;c) 5 to 40% by volume porosity that may be open or closed;wherein a)+b)+c) form a base material; and a protective system comprising:d) a lower protective layer that is situated directly on the base material consisting of one or more compounds comprising Si, C, B, O.sub.2 and having a thickness between 20 and 150 .mu.m;e) a central protective layer that is situated above the lower protective layer consisting of a transition metal boride and a transition metal silicide in combination with SiC, SiO.sub.2, or SiOC, and having a thickness of from 50 to 250 .mu.m; andf) an upper protective layer that is situated above the central protective layer consisting of one or more compounds comprising SiC, SiO.sub.2, MoSi.sub.2, Mo.sub.3 Si, Mo.sub.5 Si.sub.3, ZrB, ZrB.sub.2, ZrB.sub.12, Si.sub.3 N.sub.4, ZrO.sub.2, Y.sub.2 O.sub.3, Al.sub.2 O.sub.3, mixed oxides Al.sub.2 O.sub.3 --SiO.sub.2, and SiOC and having a thickness of from 20 to 250 .mu.m.