A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite

Bansal, Narottam P.

English

NASA Technical Reports Server

I11ll1111111 Il11 Il11 1111111111 lll 111 I11 1111l Ill 11111 Il1 
US005214004A 
United States Patent [19] [ill Patent Number: 5,214,004 
Bansal r451 Date of Patent: May 25, 1993 
1541 CERAMIC FIBER REINFORCED 4,588,699 5/1986 Brennan et al. ........................ 501/9 
- 1  
GLASS-CERAMIC MATRIX COMPOSITE 4,615,987 10/1986 Chyung et al. ......................... 501/8 
4,626,515 12/1986 Chyung et a]. ....................... 501/32 
[75] Inventor: Narottam P. Bansal, No. Olmsted, 4,634.683 1/1987 Dumbaugh et al. .................. 501/32 
Ohio 4,6661869 5/1987 Dumbaugh, Jr. ..................... 501/32 
4,919,991 4/1990 Gadkaree ............................ 428/113 
[73] Assignee: The United States of America as 4,992,318 2/1991 Gadkaree .......................... 501/95 X 
represented by the Administrator of 5,164,341 11/1992 Chyung et al. ................... 501/95 X 
the National Aeronautics and Space 
~ b - e ~ t i ~ ~ ,  wasfigton, D.C. Primary Examiner-Karl Group 
Attorney, Agent, or Firm-Gene E. Shook; Guy M. 
[21] Appl. No.: 892,055 Miller; James A. M a c h  
[22] Filed: Jun. 4,1992 
[51] Int. ( 3 . 5  ....................... CO3C 10/06; CO3C 14/00 
[52] U.S. c1. .......................................... 501/8; 501/32; 
501/89; 501/95; 428/428; 428/698; 264/58 
[58] Field of Search ................... 501/8, 17, 32, 95, 89, 
501/69; 264/58; 428/428, 698 
~561 References Cited 
U.S. PATENT DOCUMENTS 
4,410,635 6/1983 Brennan et al. ....................... 501/88 
4,464,475 8/1984 Beall et al. .............................. 501/9 
PI ABsTRAn 
A slurry of BSAS glass powders is cast into tapes which 
are cut to predetermined sues. Mats of continuous 
CVD-Sic fibers are alternately stacked with these ma- 
trix tapes. This tape-mat stack is warm-pressed to pro- 
duce a “green” composite which is heated to bum out 
organic constituents. The remaining interim material is 
then hot-pressed to form a BSAS glass-ceramic fiber- 
reinforced composite. 
15 Claims, 1 Drawing Sheet 
https://ntrs.nasa.gov/search.jsp?R=19930016911 2020-03-24T07:28:14+00:00Z
U.S. Patent May 25, 1993 5,214,004 
TENSILE STRAIN, PERCENT 
5,214,004 
1 
CERAMIC FIBER REINFORCED 
GLASS-CERAMIC MATRIX COMPOSITE 
ORIGIN OF THE INVENTION 
The invention described herein was made by an em- 
ployee of the U.S. Government and may be manufac- 
tured or used by or for the Government without the 
payment of any royalties thereon or therefor. 
TECHNICAL FIELD 
This invention is concerned with a ceramic fiber-rein- 
forced glassceramic matrix composite. The invention is 
particularly concerned with a high strength ceramic 
fiber reinforced composite which is refractory, strong, 
and tough for applications as high temperature struc- 
tural materials. 
It has been suggested that lithium alumino-silicate, 
magnesium aluminosilicate (cordierite), and calcium 
alumino-silicate glass ceramics reinforced with S ic  
fibers derived from polymers be used for such applica- 
tions. Commercially available Sic  fibers, known as 
Nicalon, have been satisfactory. However, the potential 
use of such prior art materials is limited to somewhat 
low temperatures of about looo’ C. to 1100’ C. 
It is, therefore, an object of the present invention to 
provide a new composite material having superior me- 
chanical properties at high temperatures. 
Another object of the invention is to provide a 
method of making a ceramic fiber-reinforced glass- 
ceramic matrix composite material for use in gas turbine 
and diesel engines. 
BACKGROUNDART 
Brennan et al U.S. Pat. No. 4,410,635 discloses silicon 
carbide fiber reinforced composites which include bar- 
ium aluminosilicates. Chyung et al U.S. Pat. No. 
4,615,987 describes silicon carbide fiber reinforced alu- 
minosilicate glass-ceramics which include barium oxide 
and strontium oxide. These may be used at temperature 
ranges of 1OOO” C.-130O0 C. 
5 
10 
15 
20 
25 
30 
35 
40 
Brennan et a1 U.S. Pat. No. 4,588,699 is directed to a 
high strength magnesium aluminosilicate glass-ceramic 
matrix with silcon carbide fibers and including barium 
oxide. The matrix may be operated at temperatures at 45 
1200” C.-l500” C. Dumbaugh, Jr. U.S. Pat. Nos. 
4,634,683 and 4,666,869 disclose barium and/or stron- 
tium oxide aluminosilicate glasses. 
Beali et a1 US. Pat. No. 4,464,475 described a glass- 
ceramic article containing osulmite (barium oxide) and 50 
which is capable of being used at temperatures of 1300’ 
C .  and higher. The bodies may be used as a matrix for 
fiber reinforced structures. Gadkaree U.S. Pat. No. 
4,919,991 is directed to a ceramic matrix composite on 
DISCLOSURE OF THE INVENTION 
The objects of the invention are achieved with a 
fiber-reinforced composite which is composed of a 
(1 - x)Bao-xSrO-A1203-2Si02 (BSAS) glass ceramic 60 
matrix where x=0.05 to 1. The matrix has been rein- 
forced with CVD Sic  continuous fibers. The method of 
assembly includes preparing a slurry of BSAS glass 
powders and casting this slurry into tapes. After the 
tapes are dried they are cut to the proper size. 
Continuous CVD-Sic fibers are formed into mats of 
the desired size. The matrix tapes and the fiber mats are 
alternately stacked in the proper orientation. This tape- 
silicon fiber yams. 55 
65 
2 
mat stack is warm pressed to produce a “green” com- 
posite. 
The “green” composite is then heated to an elevated 
temperature to bum out organic constituents. The re- 
maining interim material is then hot pressed to form a 
BSAS glass-ceramic fiber-reinforced composite which 
may be machined to size. 
DESCRIPTION OF THE DRAWING 
The objects, advantages and novel features of the 
invention will be more fully apparent from the follow- 
ing detailed description when read in conjunction with 
the accompanying drawing which is a graph showing 
the three point flexural stress-strain behavior for a 24 
fiber volume percent silicon carbide fiber/BSAS (X = 1) 
glass-ceramic composite material at room temperature. 
BEST MODE FOR CARRYING OUT THE 
INVENTION 
The composite of the present invention is produced 
by a tape method in which an aqueous slurry of glass 
powder along with a fugitive organic binder, plasti- 
cizer, glycerine, and surfactant is prepared. Glass pow- 
ders having an average particle size of about 1.5 pm 
have been satisfactory. A binder identified as Methocel 
20-214 which is a commercially available material from 
the Dow Chemical Company has been suitable. A plas- 
ticizer known commercially as Polyglycol E-400 from 
the Dow Chemical Company has been adequate. A 
surfactant material sold commercially as Tritonex 100 
has provided +isfactory results. 
This slurry is first ball milled and then cast into tapes. 
This may be facilitated by using a doctor blade. After 
the tape has dried, it is cut to size. 
Continuous CVD Sic fibers that were supplied by 
Textron Specialty Materials are wound onto a drum. 
Commercially available adhesive tape is used to hold 
the fibers in their proper position on the drum. The 
fibers are then cut into unidirectional mats of desired 
predetermined size whose fiber orientation and integ- 
rity are maintained by the adhesive tape. 
The required number of matrix tapes and fiber mats 
are alternately stacked in a desired orientation in a 
warm press die. After stacking, this material is war 
pressed to produce a “green” composite. 
The “green” composite is then removed from the 
warm press die and wrapped in either graphite foil or 
molybdenum foil. The wrapped “green” composite is 
loaded into a hot pressing die where it is heated to an 
elevated temperature between about 400” C. to 500” C. 
to bum out organic constituents to produce an interim 
material. 
The interim material is then hot pressed under vac- 
uum using temperatures of 1250’ C.-1500’ C., a pres- 
sure of 2 to 4 KSI, and a time of 15 to 120 minutes. After 
cooling to room temperature and pressures, the result- 
ing composites are then removed from the die. 
A number of the composites were cut into test bars 
for flexural strength measurements and other character- 
izations. Referring to the drawing there is shown a 
graph of the 3-point flexural stress-strain behavior for a 
24 volume percent Sic  fiber/BSAS (x=1) glass- 
ceramic matrix composite material. The flexural stress- 
strain line is for room temperature measurements. Uni- 
directional Sic  fiberA3SAS (x= 1) glassceramic matrix 
composites having room temperature 3-point flexural 
- 
3 
5,2 14,004 
stress of greater than 1000 MPA have been fabricated 
with 27 volume percent fiber loading. 
While the preferred embodiment of the invention has 
been shown and described, it will be appreciated that 
various modifications may be made to the invention 
without departing from the spirit thereof or the scope of 
the subjoined claims. This silicon carbide fiber-rein- 
forced BSAS glass-ceramic matrix composite is a new 
and improved structural material. The composite fabri- 10 
cated by the aforementioned method has mechanical 
properties’superior to existing materials and a potential 
for use at temperatures as high as 1450’ C. to 1500” C. 
What is claimed is: 
1. A method of producing a ceramic fiber-reinforced 
glassceramic matrix composite comprising the steps of 
preparing an aqueous slurry of (I-x) BaO - xSr0- 
M203-2 Si02 (x=0.05 to 1) (BSAS) glass powder, 
an organic binder, a plasticizer, glycerine, and a 2o 
surfactant, 
5 
ball milling said slurry, 
casting said slurry into tape thereby forming a glass- 
drying said glass matrix tape, 
cutting said glass matrix tape, 
winding continuous chemical vapor deposition 
(CVD) Sic  fibers onto a drum, 
cutting said fibers on said drum thereby forming a 
fiber mat, 
alternating a plurality of said glass matrix tapes with 
a plurality of said fiber mats thereby forming a 
tape-mat stack, 
warm pressing said tape-mat stack thereby forming a 35 
“green” composite, 
wrapping said “green” composite in foil, 
heating said wrapped “green” composite whereby 
organic constituents are burned out thereby form- 
hot pressing said interim material to produce a silicon 
carbide fiber-reinforced (BSAS) glass-ceramic ma- 
trix composite. 
2. A method as claimed in claim 1 wherein the 
(BSAS) glass powder has an average particle size of 
about 2.5 pm. 
3. A method as claimed in claim 1 wherein the plasti- 
cizer in the slurry is polyglycol. 
4. A method as claimed in claim 1 wherein the or- 50 
ganic constituents are burned out at about 4 W  C. to 
about 500” C. 
matrix tape, 
25 
30 
ing an interim material, and 40 
45 
4 
’ 5. A method as claimed in claim 1 wherein the S ic  
fiber comprises about 24 volume percent of the compos- 
ite. 
6. A method as claimed in claim 1 wherein the 
“green” composite is wrapped in graphite foil. 
7. A method as claimed in claim 1 wherein the 
‘‘green” composite is wrapped in molybdenum foil. 
8. A method as claimed in claim 1 wherein said 
“green” composite is hot pressed at a temperature be- 
tween about 1250’ C. and about 1500” C. 
9. A method as claimed in claim 8 wherein the hot 
pressing occurs at a pressure between about 2 KSI and 
about 4 KSI. 
10. A method as claimed in claim 9 wherein said hot 
pressing occurs at a time between about 15 minutes and 
about 120 minutes. 
11. In a method of forming a silicon carbide fiber- 
reinforced glass-ceramic matrix composite the steps of 
alternating a glass-matrix tape composed of (I-x) 
BaO-xSr0 - A I 2 0 3  - 2Si02 (x=0.05 to I), organic 
binder, plasticizer, glycerine, and surfactant, with a 
fiber mat comprising about 20 percent to about 40 
percent by volume of silicon carbide fibers thereby 
forming a tape-mat stack, 
warm pressing said stack thereby forming a “green” 
composite, 
heating said “green” composite thereby burning out 
organic material therefrom, 
hot pressing the resulting material at a temperature of 
about 1250’ C. to about 1500” C. for about 15 min- 
utes to about 120 minutes at a pressure of about 2 
KSI to about 4 KSI thereby producing a silicon 
carbide fiber-reinforced glass-ceramic matrix com- 
posite, and 
cooling said composite to room temperature. 
12. A method as claimed in claim 11 wherein the 
plasticizer is polyglycol. 
13. A method as claimed in claim 11 wherein the 
composite comprises about 24 volume percent S i c  fi- 
bers. 
14. A silicon carbide fiber-reinforced glass-ceramic 
matrix composite for use at temperatures up to about 
1500” C. comprising 
about 20 to about 40 percent of silicon carbide fiber 
by volume percent, and 
about 60 percent to about 80 percent of a glass- 
ceramic matrix by volume percent, said glass- 
ceramic matrix comprising (1-x) BaO - xSr0 - 
A1203 - 2,5302 (x=0.05 to 1). 
15. A composite as claimed in claim 14 wherein the 
silicon carbide fiber content is about 24 volume percent. * * * * *  
55 
60 
65 


Ceramic fiber reinforced glass-ceramic matrix composite

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server