U.S. patent application number 11/607345 was filed with the patent office on 2010-09-02 for three dimensional reinforced cmc articles by interlocking two dimensional structures.
This patent application is currently assigned to Siemens Power Generation, Inc.. Invention is credited to Alfred Paul Matheny, Gary B. Merrill, Jay A. Morrison, Steve James Vance.
Application Number | 20100221485 11/607345 |
Document ID | / |
Family ID | 42667260 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100221485 |
Kind Code |
A1 |
Vance; Steve James ; et
al. |
September 2, 2010 |
THREE DIMENSIONAL REINFORCED CMC ARTICLES BY INTERLOCKING TWO
DIMENSIONAL STRUCTURES
Abstract
The interlocking of two or more sections via the insertion of
one or more out-of-plane features in one section or combination of
sections through a void in one or more a complementary sections can
result in a reinforced ceramic matrix composite article upon
securing of the sections. The sections can be secured by friction
between two tightly matched sections or by the use of a pin, hook,
or clamp. The sections can be constructed from one or more CMC
laminate sheets. The out-of-plane feature can be a loop or a flange
and the void can be an orifice or a matched loop in the
complementary sheet. The securing of the sections can result in a
CMC article where the delamination between sheets is inhibited.
Inventors: |
Vance; Steve James; (Oviedo,
FL) ; Merrill; Gary B.; (Orlando, FL) ;
Matheny; Alfred Paul; (Jupiter, FL) ; Morrison; Jay
A.; (Oviedo, FL) |
Correspondence
Address: |
Siemens Corporation;Intellectual Property Department
170 Wood Avenue South
Iselin
NJ
08830
US
|
Assignee: |
Siemens Power Generation,
Inc.
|
Family ID: |
42667260 |
Appl. No.: |
11/607345 |
Filed: |
December 1, 2006 |
Current U.S.
Class: |
428/99 ;
156/89.11; 428/100; 428/120; 428/122; 428/139 |
Current CPC
Class: |
Y10T 428/24281 20150115;
Y10T 428/24198 20150115; B32B 38/0012 20130101; B32B 2038/045
20130101; C04B 2237/62 20130101; Y10T 428/24182 20150115; Y10T
428/24339 20150115; B32B 18/00 20130101; C04B 2237/38 20130101;
Y10T 428/24008 20150115; B32B 38/00 20130101; C04B 2237/64
20130101; Y10T 428/24289 20150115; Y10T 428/24017 20150115; B32B
2315/02 20130101; B32B 38/10 20130101 |
Class at
Publication: |
428/99 ; 428/139;
428/100; 428/122; 156/89.11; 428/120 |
International
Class: |
B32B 7/04 20060101
B32B007/04; B32B 3/24 20060101 B32B003/24; B32B 7/08 20060101
B32B007/08; B32B 18/00 20060101 B32B018/00; B32B 37/14 20060101
B32B037/14 |
Claims
1. A reinforced CMC article, comprising: one or more sections, each
section comprising one or more generally planar laminate sheets
wherein at least one of said sections has one or more out-of-plane
features: one or more complementary sections comprising one or more
generally planar laminate sheets wherein said complementary section
has one or more macroscopic voids topographically matched to accept
the one or more out-of-plane features of said sections; and wherein
at least a portion of the one or more out-of-plane features
protrude at least partially through the one or more generally
planar laminate sheets forming the one or more complementary
sections.
2. The CMC article of claim 1, wherein said out-of-plane feature
comprises a loop and said void comprises an orifice.
3. The CMC article of claim 1, wherein said out-of-plane feature
comprises a loop and said void comprises a matching loop.
4. The CMC article of claim 1, further comprising one or more means
to secure the section to the complementary sections wherein the
opposing faces of said section and said complementary section are
held in contact.
5. The CMC article of claim 4, wherein said means to secure
comprises a pin, a hook, or a clamp.
6. The CMC article of claim 1, wherein said out-of-plane feature
comprises a flange and said void comprises a slot.
7. The CMC article of claim 6, wherein said flange contains a hole
through which a means to secure can be inserted.
8. The CMC article of claim 1, wherein said out-of-plane feature
comprises a flange with one or more grooves, said void comprises a
slot wherein the translation of said slot into said groove secures
said section to said complementary section.
9. The CMC article of claim 8, wherein two grooves are on opposite
sides of said flange, said slot comprises two split portions of a
pair of complementary sections, wherein translation of said two
split portions of said slot into said two grooves secures said
section to said complementary sections.
10. A reinforced CMC article comprising: one or more sections, each
section comprising one or more generally planar laminate sheets
wherein said section has one or more out-of-plane feature at the
edge of the section: one or more complementary sections comprising
one or more generally planar laminate sheets wherein said
complementary section has one or more one or more out-of-plane
features at the edge of the complementary section that are
topographically matched to the one or more out-of-plane features of
said sections; a locking member residing in a channel defined by
the out-of -plane feature of said section extending across the
interface of the section and the complementary section and the
out-of-plane feature of said complementary section extending across
the interface of the section and the complementary section; and
wherein at least a portion of the one or more out-of-plane features
protrude at least partially through the one or more generally
planar laminate sheets forming the one or more complementary
sections and at least a portion of the one or more out-of-plane
features of the one or more complementary sections protrude at
least partially through the one or more generally planar laminate
sheets forming the one or more complementary sections.
11. The CMC article of claim 10, wherein the locking member is a
rod or a rope.
12. A method of construction of a ceramic matrix composite article
comprising the steps of: providing one or more sections, each
section comprising one or more generally planar laminate sheets
wherein at least one of said sections has one or more out-of-plane
features; providing one or more complementary sections comprising
one or more generally planar laminate sheets wherein said
complementary section has one or more macroscopic voids
topographically matched to accept the one or more out-of-plane
features of said sections, wherein at least a portion of the one or
more out-of-plane features protrude at least partially through the
one or more generally planar laminate sheets forming the one or
more complementary sections; inserting said out-of-plane features
of said sections into said voids of said complementary sections,
and heating said section and said complementary section to cure the
matrix.
13. The method of claim 12, further comprising the steps of:
providing one or more means to secure said sections to said
complementary sections; and inserting said means to secure through
said out of plane feature wherein the opposing faces of said
section and said complementary section are held in contact.
14. The method of claim 13, wherein said means to secure comprises
a pin, a hook, or a clamp.
15. The method of claim 12, wherein said out-of-plane feature
comprises a loop and said void comprises an orifice.
16. The method of claim 12, wherein said out-of-plane feature
comprises a loop and said void comprises a matching loop.
17. The method of claim 12, wherein said out-of-plane feature
comprises a flange and said void comprises a slot, and wherein said
flange contains a hole through which a means to secure can be
inserted.
18. The method of claim 12, wherein said out-of-plane feature
comprises a flange with one or more grooves, said void comprises a
slot wherein inserting of said slot into said groove secures said
section to said complementary section and wherein two grooves are
on opposite sides of said flange, said slot comprises two split
portions of a pair of complementary sections, wherein inserting of
said two split portions of said slot into said two grooves secures
said section to said complementary section.
19. A method of construction of a ceramic matrix composite article
comprising the steps of: providing one or more sections, each
section comprising one or more generally planar laminate sheets
wherein said section has one or more out-of-plane feature at the
edge of the section; providing one or more complementary sections
comprising one or more generally planar laminate sheets wherein
said complementary section has one or more one or more out-of-plane
features at the edge of the complementary section that are
topographically matched to the one or more out-of-plane features of
said sections, wherein at least a portion of the one or more
out-of-plane features protrude at least partially through the one
or more generally planar laminate sheets forming the one or more
complementary sections and at least a portion of the one or more
out-of-plane features of the one or more complementary sections
protrude at least partially through the one or more generally
planar laminate sheets forming the one or more complementary
sections; placing said sections in contact with said complementary
sections such that a channel is defined by the out-of -plane
feature of said section extending across the interface of the
section and the complementary section and the out-of-plane feature
of said complementary section extending across the interface of the
section and the complementary section; providing a locking member
inserting said locking member into said channel; and heating said
section and said complementary section to cure the matrix.
20. The method of claim 19, wherein the locking member is a rod or
a rope.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to reinforcement of laminated
ceramic matrix composite materials by interlocking out-of-plane
features of combined sections.
BACKGROUND OF THE INVENTION
[0002] Ceramic matrix composites (CMC) have demonstrated utility as
parts for turbines and other high temperature applications. CMC
structures are most commonly constructed in the form of a
two-dimensional (2D) laminate. A 2D laminate is constructed where
two or more sheets of impregnated fibers, typically in the form of
a woven cloth, are pressed together and heated to cure the matrix
in and between the sheets. The life-limiting failure of such a
structure is often due to delamination during repetitive thermal
and mechanical cycling of the part due to shear failure in the
matrix between fiber sheets. There is no cross-ply reinforcement in
the 2D fiber architecture. Presently, most matrix materials
delaminate under stress.
[0003] The mechanical reinforcement of a 2D laminate has been
accomplished by the use of metallic fasteners placed through the
sheets for the reinforcement of the laminate. Special bushings have
been shown to compensate for the mismatch of thermal expansion
characteristics of the ceramic and the metal placed through the
sheets for the reinforcement. However, this approach is not always
desirable. For many applications, the temperatures to which the
metals are exposed are very high or the presence of the metal on
both faces of the laminate is contradictory to the requirements for
the article made from the composite. Nevertheless, in the absence
of a matrix material of sufficient resistance to shear, mechanical
reinforcement provides an attractive solution. A reinforcement that
does not use a metal, or does not use a metal at a heat exposed
surface, is desirable.
[0004] A ceramic matrix composite fastener has been disclosed in
U.S. Pat. No. 6,042,315. The structure has a head and a shank such
that the shank can be passed through a slot in a laminate panel.
The head and slot are cut to have matching surfaces such that the
panel can be attached to a housing. The fastener is constructed by
a lay-up of fabric or tape where the fibers or tow are oriented at
-45, 0, 45 and 90 degrees to yield a quasi-isotropic laminate. In
this manner the stress on the head is partially carried by some
fibers essentially aligned with the stress. Unfortunately, this is
not necessarily the case with the panel where the stress is applied
by the fastener perpendicular to the orientation of the fibers,
resulting in the potential to promote the delamination of the
panel.
SUMMARY OF THE INVENTION
[0005] A reinforced CMC article is constructed of two or more
sections where each section is composed or one or more laminate
sheets. One or more sections have one or more out-of-plane features
that extends through one or more topography matched macroscopic
voids in one or more complementary sections. The interface of the
complementary sections make continuous intimate contact. The
out-of-plane portion can be a loop and the void can be an orifice.
Alternately the void can be a matching loop. The out-of-plane
portion can be a flange and the void can be a slot. Additionally,
one or more means to secure the complementary sections via the
out-of-plane portion can be provided. The means to secure the
sections can be a pin, hook, clamp or other suitable structure
which can be inserted through one or more loops.
[0006] The CMC article can have a flange, as the out-of-plane
portion and the void can be a tightly fitting slot where friction
between the slot and the flange placed through it secures the
complementary sections. The flanges can contain a hole through
which a pin, a hook, a clamp, or other suitable structure can be
inserted through the hole. The flange can have one or more grooves
where the complementary section can be secured by translating the
slot into the groove in the flange. The grooves can be on both
sides of the flange and the slot can be divided between two split
portions of the complementary section, such that the sections can
be secured by translating the two parts of the slot into the two
grooves of the flange.
[0007] A reinforced CMC article can comprise two or more sections
defined by a continuous interface with matching topography where
one or more portions of an edge of one section extend beyond the
interface between the sections and one or more complementary
portions of an edge of a complementary section extends beyond the
interface between the sections. The complementary portions of the
edges form a channel where a locking member can reside in the
channel to secure the sections. The locking member can be a rod or
rope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an exploded perspective of a CMC article where a
loop in one section is inserted into an orifice of a complementary
section.
[0009] FIG. 2 is an exploded perspective of a CMC article where a
loop resulting by removal of portions of a sheet or an ensemble of
sheets of one section is inserted into an orifice in a
complementary section.
[0010] FIG. 3 is an exploded perspective of a CMC article where a
loop results from the weaving of a section where: (a) no fabric is
present below the loop; and (b) where the weave has resulted in a
loop with fabric below the loop.
[0011] FIG. 4 is an exploded perspective of a portion of a CMC
article where: (a) a section with cut loops are inserted into
complementary loops in a complementary section with matching loops,
and (b) a section with a woven loop with fabric below the loop is
inserted into a complementary woven loop where no fabric is present
below the loop in a complementary section.
[0012] FIG. 5 is an exploded perspective of a CMC article where a
flange of one section is inserted into a slot in a complementary
section where: (a) the flange is secured by friction between the
flange and slot; (b) the flange contains a hole to be alternately
or additionally secured by a pin or hook; and (c) where the flange
is formed by the weaving of the fabric and secured by friction
between the flange and the slot.
[0013] FIG. 6 is an exploded perspective of a portion of a CMC
article using a grooved flange where: (a) the slot is formed by a
combination of two portions and placed in two grooves on the flange
to secure the flange; and (b) the flange has a single groove, which
can be fitted into the slot and translated in the slot to secure
the flange.
[0014] FIG. 7 is an exploded perspective of a portion of a CMC
article where a combined flange section can be assembled from two
or more flange sections and secured by friction of the flanges with
a single complementary slotted section.
[0015] FIG. 8 is a perspective view of a CMC article where friction
secures some flanges and other flanges have holes to provide
additional or alternate means of securing or for mounting of the
combined article to a structure.
[0016] FIG. 9 is an exploded perspective a portion of a CMC article
where an edge reinforcement results when a channel is formed from
the deflection of edge segments out-of-plane and locked with a
rod.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The reinforcement of a CMC structure is accomplished
according to the insertion of an out-of-plane feature of one
section, which comprises a single fabric sheet or an ensemble of
sheets, that is topographically matched to a void to receive the
out-of-plane feature in a complementary section. The complementary
section independently comprises a single fabric sheet or an
ensemble of sheets. The out-of-plane feature is secured after its
insertion through the void by friction or by mechanically
interlocking or by using a means to lock the layers that forces
intimate contact of the sections at the interface between the
sections. The means can impose a compressive force on the interface
between the sections. In this manner, the delamination of the
sections in the vicinity of the out-of-plane feature is inhibited.
The inhibition of delamination in the vicinity of the out-of-plane
interlocking features can inhibit delamination throughout the
structure or can halt the propagation of a shear defect generated
elsewhere in the structure. The resulting reduction of the
propensity to delaminate between sheets of the CMC can extend the
life cycle of the CMC article. The invention permits the
construction of thinner walled CMC parts, resulting in a reduction
of the thermal stresses imposed on the article and a higher surface
to volume ratio, which alleviates some of the cooling requirements.
The material costs also decline proportionally with the thickness
of the composite. As follows, the invention is described in terms
of two complementary sections. It is to be understood that the
sections can independently comprise a single sheet or an ensemble
of sheets.
[0018] As shown in FIG. 1, the out-of-plane feature can be a loop
11 in one section 10 which is fitted through an orifice 21 of the
appropriate shape and size in a complementary section 20 to permit
the intimate contact of the two inner faces 13 and 23 of the two
sections 10 and 20. The composite can be held tightly together by
snugly fitting a pin or other suitable structure into hole 14 where
the loop 11 extends through the orifice 21. The pin can be
constructed of a metal or alloy. If needed for use in a very high
temperature application, the pin can be a ceramic or ceramic
composite. Other materials are acceptable if permitted by the
thermal environment and the tolerance of the pin and CMC materials
to any thermal expansion differences.
[0019] The loop 11 may be formed by making two cuts 12 of a
relatively short length on a section 10, as shown in FIG. 1. It is
preferable that the cuts 12 be between individual fibers or tows of
the fabric where the cuts 12 are formed parallel to one set of tows
in the woven pattern such that the loop 11 includes a plurality of
tows which are parallel to the cuts and continuous over the entire
loop 11. No other fabrication is necessary to prepare the section
if the article prepared from the composite can be used with a small
protrusion 15 from the surface opposite the surface where the loops
11 reside upon fabrication, which results from the insertion of the
pins or other means of securing the sheets. The protrusion 15 can
be minimized in size by using a flat pin.
[0020] If the ultimate use of the composite article requires that
one surface has no protrusions from the primary plane of the
composite, as shown in FIG. 2, cuts 36 on the section can be made
perpendicular to two cuts 32 and the fabric between the cuts 36 can
be removed. In this manner the area between the first two cuts 32
can be displaced out-of-plane to form the out-of-plane loop 31
bringing the edges 37 remaining after the removal of fabric into
contact, as shown in FIG. 2.
[0021] Alternately, particularly when the section is a single
sheet, the fabric can be woven to form one or more loops 41 on a
section 40 as shown in FIG. 3(a). The loops formed in the manner
illustrated in FIGS. 1, 2 and 3(a) leave an open space on the face
to be exposed to the hot environment. This may be inappropriate for
some applications and may necessitate the use of a ceramic pin. As
shown in FIG. 3(b), weaving techniques can be applied that permit
the first section 40 to display loops 41 with a continuous fabric
48 underneath the loop 41 where some of the tows are used to form
the out-of-plane loop while other tows are woven in the continuous
plane of the fabric. This approach is particularly practical where
the section 40 is a single sheet of fabric.
[0022] As illustrated in FIGS. 1, 2 and 3, the orifice 21 can be
cut from the complementary section 20 with the width of the orifice
21 equal to or slightly greater than the width of the loop and long
enough to permit the entire loop to extend through the orifice 21
and force the inner faces of the sections tightly together when the
pin is inserted into the loop. The pin must be longer than the
width of the orifice that accepts the loop. The pin may be of a
length such that it is inserted into one loop or a series of loops
depending upon the size of the structure and the application for
which the structure is to be used. One end of the pin may be
deflected at an angle, for example an L shaped pin with a
deflection of 90.degree., which can prevent the pin from slipping
out of the loop during subsequent use of the part if the friction
imposed on the pin is insufficient to assure that the pin remains
where placed. The sections can be secured by locking with a hook
rather than a pin. The hook or pin can be used to secure the
article to an additional structure. Generally, although not
necessarily, it is intended that the pin or hook are on the face of
the composite that will be exposed to lower temperatures during its
ultimate use.
[0023] The construction of the 3D article can be carried out before
curing and the entire pre-impregnated composite article can be
cured in a single step. Alternately one section, either that with
the loop or the orifice, can be cured or partially cured prior to
the construction of the 3D structure followed by a second curing
step after assembly. Alternately, the two sections can be
individually cured or partially cured and then the 3D structure
assembled and subsequently cured a second time with or without
additional matrix material. Optionally, additional fabric can be
used to enhance the properties of the structure.
[0024] An alternative to the orifice on the complementary section
50 is a matching loop 51 as illustrated in FIG. 4(a). In this
manner cuts 52 and 62 are made to both sheets 50 and 60 such that
the loops 61 of one section 60 fit into the loops 51 of the
complementary section 50, which can allow a pin or other means of
mechanically securing the sections to be inserted through the hole
64 defined by the combined loops 51 and 61. A protrusion 65 on the
surface that will be exposed to high temperatures is needed to
allow the insertion of a pin or other means to secure the sections.
If a smooth surface is required for a face of the article, it is
preferable if the loops 71 and 81 are prepared during the weaving
process, as illustrated in FIG. 4(b), rather than by the formation
of loops via cuts. FIG. 4(b) shows a section 80 where the weave is
continuous 88 under the loop 81. The complementary section 70 is
constructed such that an open area 78 permits the insertion of the
loop 81 into the complementary loop 71. Loops which are formed by
removing fabric and bringing edges into contact, as in FIG. 2, have
a slit through both sections and under some conditions of use can
potentially promote failure at the slit. This potential slit
induced failure can be addressed by having a continuous woven
fabric under the loop 81.
[0025] Another type of out-of-plane feature that can be used is to
have a flange in one section that can be fitted through a slot in
the complementary section. As shown in FIG. 5 the section 110 with
the flange 111 can be cut from a fabric sheet such that the flange
portion can be deflected 90.degree. and fit through a slot 121 in
the complementary section 120. As shown in FIG. 5(a), the width of
the slot 121 in the complementary section 120 can be sufficiently
narrow such that forcing the flanges 111 through the slot 121 locks
the flanges 111 together and secures the interface between the two
sections 110 and 120. In this manner the matched fit of the flanges
111 and slot 121 is the means to lock the sections together with
intimate contact of the inner surfaces. Particularly when the
flanges are fed through the slots prior to curing, the flanges 111
can be pressed against the complementary slot section 120 and cured
to further lock the sections together and reduce the thickness of
the CMC article. Alternately or additionally, as in FIG. 5(b), the
flanges 111 can have a hole 113 in them where a pin or hook can be
inserted locking the sections in intimate contact. As described
previously, alternately or additionally, the pin or hook can be
used to mount the CMC article to a substructure of the ultimate
device. The section containing the flange 111 may also be woven in
this form where the first section 110 is composed of a single sheet
as shown in FIG. 5(c).
[0026] FIG. 6(a) illustrates an embodiment where a flange section
130 is matched to a complementary split slotted section 140. The
flange section 130 includes a groove 134 at the base of the flange
131 where the width of the groove 134 is equal to the thickness of
the complementary section. The complementary split section 140
requires the combined slots 141 to be approximately equal in length
to the length of the flange 131 minus the length of the grooves 134
in the flange. The means to lock the sections is the insertion of
the slots 141 on the complementary section 140 into the grooves 134
in the flanges 131. The flanges 131 can be pressed against the
complementary split section 140 if constructed before curing to
further lock the sections or reduce the thickness of the
article.
[0027] FIG. 6(b) illustrates a variation on the use of a flange
section 130 with a groove 134 where the groove 134 is formed on
only one side of the flange 131. The complementary slotted section
140 can be constructed as a single piece where the slot 141 is the
full length of the flange 131. Locking of the sections 130 and 140
occurs when the flange 131 is placed through the slot 141 and the
flange section 130 is displaced such that the groove 134 slides
over the complementary section and the portion of the flange 131
above the groove 134 is also in intimate contact with the slotted
section 140. In this variation a portion of the slot 141 is not
filled with the flange 131 when assembled.
[0028] The out-of-plane flanges of one section of the type shown in
FIG. 5 can be formed along the edge of a single or stack of fabric
sheets such that little of the sheet is discarded during the
manufacture of a CMC article and multiple sites of 3D reinforcement
are formed along each edge. As shown in FIG. 7 sections 150 can be
constructed from a single sheet or stack of fabric sheets where
perpendicular cuts 152 and 153 define flanges 151 when folded
out-of-plane. Two or more of these sections 150 can be fit together
to form a combined section 160 with combined flanges 161. A
complementary section 170, with slots 171 cut in the appropriate
place to accept the combined flanges 161 forms an article, can then
lock this combined section 160. Although FIG. 7 displays a section
held together by a tight fit of the combined flanges 161 and slots
171 in the manner illustrated in FIG. 5(a), holes can be drilled in
the combined flanges 161 to accept a pin to lock the sections
together as in FIG. 5(b). FIG. 8 shows a structure such as that of
FIG. 7 where the majority of combined flanges 161 have been pressed
against the slot sheet 170 with the exception of four flanges where
holes 164 have been drilled such that a pin can be inserted to
anchor the CMC article to a substrate.
[0029] The out-of-plane features can be a portion of the edge of a
section as illustrated in FIG. 9. The complementary sections 200
and 210 have the out-of-plane features 201 and 211 extending beyond
the edges. The complementary sections begin a continuous interface
when inner faces 203 and 213 are pressed together. The features are
deflected across the interface such that the out-of-plane features
201 or 211 of each section 200 or 210 cross the interface where a
complementary section 210 or 200 has a complementary void. The
complementary out-of-plane features 201 and 211 combine to define a
channel to accept a locking member 205. The locking member 205 can
be a rod or a braided rope, which is inserted into the channel
forcing the interface of the two sections 200 and 210 to be
intimately contacted and secured.
[0030] Reinforcement of the edge can be constructed from a flange
inserted into a slot in the manner illustrated in FIG. 5 or FIG. 6.
The flange and slot are near the edge of their respective sections,
and the out of plane deflection is provided at only one face of the
CMC article rather than at both faces of the CMC article.
[0031] These and other embodiments are possible and it should be
understood that the invention is not limited to the particular
embodiments illustrated and described. Variations and modifications
can be made without departing from spirit and scope of the novel
concept as defined in the claims.
* * * * *