DE102018201555A1 - CMC moldings, as well as manufacturing method - Google Patents

Abstract

The invention relates to a shaped body such as a turbine component, in particular a guide or moving blade of a gas turbine and / or a component of an exhaust line, at least partially made of CMC, so - ceramic matrix composite - and / or a CMC metal Hybrid, is constructed and a new, especially in terms of mechanical, thermomechanical and / or thermal stability improved, realized design concept. By means of the invention, for the first time, a CMC molded body or a CMC hybrid molded body is presented which comprises a composite of an inner wound CMC part with an outer CMC part realized in the stack construction concept.

Description

The invention relates to a shaped body such as a turbine component, in particular a guide or moving blade of a gas turbine and / or a component of an exhaust line, at least partially made of CMC, so - ceramic matrix composite - and / or a CMC metal Hybrid, is constructed and a new, especially in terms of mechanical, thermomechanical and / or thermal stability improved, realized design concept.

So far, for example, moldings such as turbine blades, for example for stationary gas turbines, are made of nickel-based superalloys with additional protective coatings, e.g. TBC coatings used. Although the properties of these materials are constantly being developed, this technique seems to be quite exhausted and, according to general estimation of the experts, little substantial increase is still possible.

In contrast, the technique of component assembly with CMCs, so the fiber-reinforced ceramic materials is an alternative alone and / or in combination with sub-elements of metals and in particular of superalloys, as so-called CMC metal hybrid moldings, to create novel moldings such as turbine components and / or components in an exhaust system still profitable, so leading to substantial increases, can be used. In combination with alloys, in particular of the abovementioned superalloys, or also other metals, this is then referred to as a shaped body made of hybrid material which comprises CMC subelements and metal subelements.

As a rule, a CMC subelement comprises a fiber, a fiber composite, a woven fabric and / or a three-dimensional composite of reinforcing fibers, in particular of ceramic reinforcing fibers, which is embedded in a ceramic matrix. For production, prepreg layers are usually laminated together and subsequently sintered to form the ceramic CMC molding. The arrangement of the CMC layers to each other is a critical point and it is constantly on an optimal arrangement of the CMC layers to each other, so to design concepts for the components, be it for turbines and / or elements of an exhaust system researched.

For example, a known turbine component includes a laminate of CMC layers based on CMCs of oxide and / or silicon carbide ceramic. The laminates are deposited or stacked as prepreg layers on the one hand in the so-called stack construction concept on a metal core and / or on a support structure. Alternatively, in the so-called wrap construction concept, the prepreg layers are wound around a core or support structure. In both cases, after drying and / or heat treatment, the prepreg layers are sintered with or without support structure.

In particular, in the production of CMC-based guide vanes for stationary gas turbines, either the wrap, ie the winding build-up concept, or the stack, that is the stack construction concept, has hitherto been realized.

Such manufactured CMC moldings for turbine components and / or components of an exhaust line are then in principle suitable, exposed to extremely high thermal, thermomechanical and mechanical loads. However, they should also be suitable for the formation of an effective component cooling and / or have a surface which has sufficient hardness for pretreatment by roughening, for a suitable adhesion of a TBC layer to be applied. These two points, the formation of the cooling structure within the component on the one hand and the surface condition on the other hand still make problems according to the conventional construction concepts. In addition, conventionally constructed CMC moldings exhibit anisotropic strength.

In the winding structure concept, the CMC layers are built up in layers parallel to the outer contour of the finished molded body and in the stack construction concept, the individual layers are usually perpendicular to the outer contour of the finished molded body, both structural concepts advantages and disadvantages with respect to mechanical, thermomechanical and / or thermal resilience. In particular, the low interlaminar strength of a CMC partial element can have a disadvantageous effect on the thermo-mechanical load-bearing capacity and / or the surface hardness of the finished molded article.

Therefore, there is still a need to provide a new design concept for a CMC molding or a CMC hybrid molding with increased mechanical, thermo-mechanical and / or thermal capacity.

It is therefore an object of the present invention to provide a design concept for CMC molded bodies which exhibits improved mechanical, thermomechanical and / or thermal resistance compared with the prior art.

This object is achieved according to the invention by the subject matter as disclosed in the description, the figures and the claims.

Accordingly, the subject matter of the invention is a CMC molded body or CMC hybrid molded body comprising a combination of at least one wound -WRAP and at least one stacked -STACK CMC part made of individual laminate layers,
characterized in that
an internal, implemented in the wrap design concept first CMC part is at least partially surrounded by an external, implemented in the stack design concept second CMC part, so that a material-locking composite of the at least two surrounding CMC parts results, the two CMC parts reinforce each other by having CMC laminate layers of the first and second CMC parts oriented at least partially transverse to one another.

In addition, the present invention is a process for producing a CMC molding or a CMC hybrid molding, wherein in a first process step, two CMC parts, a first CMC part in the wrap design concept and a second CMC part in the stack Construction concept are produced, which are then combined with each other in a subsequent step to form a material-bonded composite.
According to an advantageous embodiment of the invention, at least a first and a second CMC part are connected so that a positive connection results.

In particular, the construction of an internal CMC part produced, for example, by means of a wrap construction concept, will take place by lamination on a core structure. If necessary, this is combined with one or more further wrap CMC parts with one or more external CMC part (s) in the stack design concept.

The contact surfaces between the individual CMC layers and / or between CMC parts can be connected to the matrix used for a CMC prepreg layer and / or via a glass ceramic or a mixture of the matrix material and a glass ceramic and / or via a corresponding penetration become.

The ceramic matrix can have a gradually increasing proportion of glass ceramic within a stack or within a winding. In particular, the matrix of the upper or uppermost layer of one or more CMC parts may be modified by the addition of glass ceramic constituents in such a way that an increased hardness results on the surfaces of the body modified with glass ceramic constituents.

In this way, a very robust CMC molded body or CMC hybrid molded body is produced, which advantageously by the novel combination, the excellent mechanical stability and / or damage tolerance produced in the wrap design concept CMC parts with the advantageous properties and in particular the outer surfaces of built according to the stack design concept CMC parts, connects.

The CMC parts, which are manufactured in the wrap design concept, give the CMC molded body torsional and / or torsional stability, whereas the CMC parts realized in the stack design concept have a surface with excellent hardness, which is suitable for coatings or pretreatment for application of Coatings is well suited.

General knowledge of the invention is that a combination of the two structural concepts, at least one inner and wound CMC part and at least one outer and stacked CMC part, the mechanical, thermomechanical and / or thermal load capacity of a CMC molding or CMC hybrid thus produced Increase drastically. The reinforcement of the two parts compensates for their instabilities, especially in the manufacture of turbine components, such as blades. In particular, it has proved to be advantageous if the at least two CMC parts are connected by a common matrix or mixture of matrix and glass ceramic, so that a composite with high strength results.

Therefore, according to an advantageous embodiment, the two connected CMC parts by a matrix or a mixture of matrix and glass ceramic, in which the two mutually transverse CMC parts are at least partially, in particular at least partially embedded at the contact surfaces, connected.

In the present case, a CMC laminate layer is a so-called "ply", which can be produced by submission and / or dipping or similar wetting and / or impregnation of a reinforcing fiber master into a ceramic slip and subsequent drying and sintering.

In the wrap design concept, in which a CMC part is built up in layers with the CMC layers parallel to the outer contour of the guide vane, complicated components, such as guide vane components, can be produced with the aid of appropriate molding tools, but with the weak ones oriented parallel to the component surface Matrix layers with low interlaminar strength also result in considerable disadvantages. For example, by impact, "rub-in" and / or high thermomechanical load damage the outer layer and in the worst case a delamination. In addition, the wrap-building concept usually no protective layer can be applied with the required liability, because the outermost layer can not be pretreated without corresponding damage and / or roughen.

In contrast, a CMC part - for example, a barrel or vane - roughened well superficial on the stack construction concept and is very robust to thermo-mechanical stress and / or impact. This is particularly because the reinforcing fibers are basically arranged transversely to the outer contour and are therefore very robust and insensitive to a surface treatment, for example for preparing a protective coating. However, a CMC part can not transfer tensile forces in the vertical direction in the vertical direction, and there is a risk of hot gas leakage due to possible cracks between the CMC laminate layers. Due to the cracks, hot gas can enter the interior of the component and damage existing metallic parts and / or other structures there.

By the present invention, the two concepts wrap and stack are combined for the first time so that the outer contour of the CMC molding can be well prepared for a subsequent coating and at the same time results in a torsional strength of the CMC molding by the core produced in the wrap design concept.

In addition, the combination of the respective CMC parts by a common bedding matrix, which brings together both CMC subelements results in a special operating stability of the CMC molded body against cracks. Thus, a 3-dimensional CMC structure with isotropic strength results in all in the CMC molded body three spatial directions.

According to an advantageous embodiment of the invention, the at least two CMC parts are connected to each other by a high temperature resistant ceramic matrix.

According to a further advantageous embodiment of the invention, the at least two CMC parts are connected by a high-temperature-resistant ceramic matrix comprising a glass ceramic.

The layers, in particular the laminate layers of the at least two, a CMC parts produced according to the wrap construction concept and a stack construction concept, lie transversely to one another. Advantageously, they are approximately at right angles to each other, and of course also different geometries can be realized turned off on the moldings to be produced in each case. The decisive factor here is that the orientation of the position of the one CMC part compensates for the interlaminar weakness of the layers of the other CMC part approximately and / or approximately to an isotropic strength in the CMC molding.

In the molded body, at least two CMC parts, a CMC part produced according to the stack design concept and a CMC part produced according to the wrap construction concept, form a material-bonded composite. For example, inside one, two or more CMC parts produced according to the wrap design concept can be connected to one, two or more CMC parts produced according to the stack design concept. There is no parity required, as evidenced by the embodiment shown in the figures.

As a "material-locking" composite is referred to herein, that within the composite no voids and / or air pockets are provided.

The new combined design concept with internal wound laminates and external stack-laminated CMC part offers, for example, the following advantages:

The specific roughness and characteristic of the machined CMC surface of an outer CMC part is part of a stack-laminated CMC part and thus allows a very good adhesion of, for example, APS, ie thermally sprayed, protective layers such as TBC and / or EBC because it compared to roughening techniques shows high stability.

Due to the presence of an inner, constructed according to the wrap design concept, CMC part damage due to cracks and / or hot gas can be avoided or reduced to even further inside the molded body lying - for example, metallic - parts.

By constructing a 3-dimensional CMC structure, a high strength, damage tolerance and, in particular, torsional rigidity of a shaped article produced in this way are produced.

According to an advantageous embodiment of the CMC molding is not only as composite material bond, but also as a positive connection before.

In the present case, a composite in which no projection of one of the at least two CMC parts combined for mutual reinforcement is present on the outer contour of the CMC molded body is referred to as a "positive-locking" composite.

• 1 zeigt ein CMC-Teil eines CMC-Formkörpers oder eines CMC-Hybrid-Formkörpers, das nach dem Stack-Aufbaukonzept realisiert ist.
• 2 zeigt ein CMC-Teil eines CMC-Formkörpers oder eines CMC-Hybrid-Formkörpers, das nach dem Wrap-Aufbaukonzept realisiert ist und
• 3 schließlich zeigt einen CMC-Formkörper, der eine Laufschaufel ist und die beiden, aus den 1 und 2 bekannten, CMC-Teile umfasst.

In the following, the invention will be explained in more detail by means of an example, which shows an exemplary embodiment of the invention:

• 1 shows a CMC part of a CMC molding or a CMC hybrid molding, which is realized according to the stack design concept.
• 2 shows a CMC part of a CMC molding or a CMC hybrid molding, which is realized according to the wrap design concept and
• 3 Finally, shows a CMC molding, which is a blade and the two, from the 1 and 2 known, includes CMC parts.

1 shows a stack 2 single CMC laminate layers 1a to 1f stacked on top of each other. The layers have openings 3a and 3b on. The layers 1a to 1f according to the stack construction concept are perpendicular to the outer contour of the component, the blade.

2 shows two separate, wound CMC parts 4 and 5 which are made according to the wrap construction concept. These CMC parts are designed to fit in the openings 3a and 3b of in 1 shown stack 2 Made of CMC laminate layers. The CMC parts 4 and 5 are thus as "internal cores" one of the CMC parts of the 1 and 2 composite positive composite or molded body suitable.

3 shows the positive connection 6 the three CMC parts from the 1 and 2 , one stacked CMC part and two CMC parts made according to the wrap design concept. So is a blade 6 created the two openings 7a and 7b has, for example, serve as cooling channels and / or in the possibly still metallic structures for forming a CMC (hybrid) shaped body can be introduced. The metallic or non-metallic structures constructed in an opening can be constructed, for example, by means of generative production methods and / or comprise filigree cooling systems.

By means of the invention, a CMC molded body or a CMC hybrid molded body is presented for the first time, comprising a composite of CMC parts, with an inner CMC part produced in the wrap construction concept and an outer part realized in the stack construction concept ,

Claims (15)

CMC molding or CMC hybrid molding, a combination of at least one wound and at least one stacked CMC part, each of CMC laminate layers, comprising, characterized in that an internal, realized in the wrap design concept first CMC part of an outer, realized in the stack design concept second CMC part is at least partially surrounded, so that a material-locking composite of the at least two surrounding CMC parts results, the two CMC parts in that CMC laminate layers of the first and the second CMC part at least partially oriented transversely to each other, reinforce each other. CMC molding or CMC hybrid molding after Claim 1 , wherein the material-locking composite is realized by means of a common matrix in which the mutually perpendicular laminate layers are at least partially embedded. CMC molding or CMC hybrid molding after Claim 1 or 2 , wherein the material-locking composite by means of a common matrix, the glass ceramic components comprises, in which the two transverse laminate layers are at least partially embedded realized. CMC molding or CMC hybrid molding according to one of the preceding claims, wherein the material-locking composite by means of a common matrix with glass ceramic components in which the two transverse laminate layers are at least partially, at their contact surfaces, embedded realized. CMC molding or CMC hybrid molding according to any one of the preceding claims, wherein the composite is realized by means of a corresponding penetration, which connects the two transverse laminate layers at least partially on the contact surfaces. A CMC molding or hybrid CMC molding according to any one of the preceding claims, wherein the at least two transverse laminate layers of the composite form approximately a right angle. CMC molding or CMC hybrid molding according to any one of the preceding claims, wherein the composite is also form-fitting. A process for producing a CMC molding or a CMC hybrid molding, wherein in a first process step, two CMC parts, a first CMC part in the wrap design concept and a second CMC part in the stack design concept are produced, which then in a subsequent process step are combined with each other to form a material-bonded composite. Method according to Claim 8 , wherein the combination of the two CMC parts results in a positive and material-locking composite. Method according to one of Claims 8 or 9 wherein at least two inner and first CMC parts in the wrap design concept are combined with an outboard second CMC part in the stack design concept. Method according to one of Claims 8 to 10 wherein at least part of a contact surface between two CMC parts forming a composite according to one of the Claims 1 to 7 embedded in a high temperature resistant ceramic matrix. Method according to one of Claims 8 to 11 wherein at least part of a contact surface between two CMC parts forming a composite according to one of the Claims 1 to 7 form, embedded in a glass-ceramic matrix. Method according to one of Claims 8 to 10 wherein at least part of a contact surface between two CMC parts forming a composite according to one of the Claims 1 to 7 form, is provided with a burn-in. Turbine component comprising a CMC molding or a CMC hybrid molding according to any one of Claims 1 to 7 includes. Component of an exhaust line comprising a CMC molding or a CMC hybrid molding according to any one of Claims 1 to 7 includes.

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