PLIABLE NONFLAMMABLE TAPE FOR COMPOSITE MATERIALS
Slurry and tape compositions include particles of a precursor that converts to a ceramic material when heated to a firing temperature, at least one binder that is capable of adhering the particles of the ceramic precursor together to form a pliable prepreg tape, at least one liquid plasticizer, and at least one solvent in which the binder is dissolved. The solvent may be sufficiently volatile to evaporate from the slurry composition during formation of the tape, yet the tape may also be pliable as a result of the slurry composition containing a sufficient amount of the liquid plasticizer.
1 . A pliable nonflammable tape, comprising:
a fiber reinforcement material; and
a matrix material that will form a Si-SiC ceramic matrix comprising:
a powder comprising precursor particles, the precursor particles comprising SiC, carbon and/or one or more other carbon-containing particulate materials;
one or more binders;
one or more liquid plasticizers; and
one or more solvents;
wherein the tape contains less than 10 weight percent of the one or more solvents yet is pliable as a result of containing a sufficient amount of the one or more liquid plasticizers.
2 . The pliable nonflammable tape of claim 1 , wherein the matrix material contains, by weight, 60% to 70% of the powder.
3 . The pliable nonflammable tape of claim 1 , wherein the matrix material contains, by weight, 10% to 18% of the one or more binders.
4 . The pliable nonflammable tape of claim 1 , wherein the one or more binders comprises a polymeric material selected from the group consisting of polyethylenes, polycarbonates, polyvinyl acetates, polyvinyl alcohols, polyvinyl butyral (PVB), and acrylics.
5 . The pliable nonflammable tape of claim 1 , wherein the matrix material contains, by weight, 10% to 14% of the one or more liquid plasticizers.
6 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises dibutyl phthalate.
7 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises butyl benzyl phthalate.
8 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises triethyleneglycol bis(2-ethyl hexanoate).
9 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises adipates.
10 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises glycols.
11 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises linseed oil.
12 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers comprises and castor oil.
13 . The pliable nonflammable tape of claim 1 , wherein the one or more liquid plasticizers are selected from the group consisting of dibutyl phthalate, butyl benzyl phthalate, triethyleneglycol bis(2-ethyl hexanoate), adipates, glycols, linseed oil, and castor oil.
14 . The pliable nonflammable tape of claim 1 , wherein the tape contains less than about 7 weight percent of the one or more solvents.
15 . The pliable nonflammable tape of claim 1 , wherein the one or more solvents comprise an alcohol.
16 . A method of forming a prepreg tape stack, the method comprising:
stacking at least two layers of the pliable nonflammable tape of claim 1 to form a prepreg tape stack; and
exposing the prepreg tape stack to a debulking temperature below a decomposition temperature of the one or more binder and the one or more plasticizer to form a preform containing less than 1 weight percent of the one or more solvents.
17 . The method of claim 16 , wherein the preform contains less than 0.1 weight percent of the one or more solvents.
18 . The method of claim 16 , wherein the preform comprises 25 to 40 weight percent of the one or more powders, 4 to 8 weight percent of the one or more binders, 4 to 8 weight percent of the one or more plasticizers, and the balance being the fiber reinforcement material.
19 . A method of forming a ceramic precursor, the method comprising:
heating the preform formed in claim 16 to a temperature sufficient to decompose the one or more binders and the one or more plasticizers; and
then, heating the preform to a firing temperature sufficient to convert the ceramic precursor within the matrix material into the ceramic material of the matrix of a CMC component.
20 . A slurry composition comprising:
a powder comprising particles of at least one precursor;
at least one binder capable of adhering the particles of the at least one precursor together to form a pliable tape;
at least one liquid plasticizer; and
a solvent in which the binder is dissolved, the solvent being sufficiently volatile to evaporate from the slurry composition during forming of the tape so that the tape contains less than about 10 weight percent of the solvent, yet the tape is also pliable as a result of the slurry composition containing a sufficient amount of the liquid plasticizer.