Abradable coating system
First Claim
1. An abradable coating system for clearance reduction in a turbine or a compressor, the turbine or compressor defining an axis of rotation and having blading and a component on which said system can be applied, the system comprising:
- at least one block, wherein the block comprises;
a woven or non-woven tissue or foam made of a material selected from the group consisting of ceramic, glass, glass-ceramic, ceramic-metal composite, and combinations thereof, andfiller particles, filler fibers, an inorganic polymer binder, or combinations thereof, at least partially filling the tissue or foam;
a center part, wherein at least the center part of the system has an abradability which is graded along a radial direction with respect to the axis of rotation, such that the surface region of a side facing the blading is more abradable than an opposite side facing the component, wherein the center part is stripe-like and circumferentially oriented, wherein the center part is highly abradable such that it can be abraded by the blading;
a pair of stripe-like, circumferentially oriented side parts immediately axially adjacent to the center part, wherein the side parts are less abradable than the center part; and
wherein an abradable differentiation between the center part and the side parts is achieved by using a different impregnation matrix material for the center part and the side parts.
3 Assignments
0 Petitions
Accused Products
Abstract
An abradable coating system (2-8) for a turbine or a compressor is proposed has at least one layer of woven or non-woven tissue (15) or foam made of: ceramic, glass, glass-ceramic, ceramic-metal composite and combinations thereof. A free-standing preformed element (18) has at least one layer of such a woven or non-woven tissue or foam is filled with fillers and/or binder. A method prepares such a system. Finally, a method for the repair of an abradable coating portion of a turbine or the compressor component (9) includes in a first optional step that the damaged portion is at least partly removed and/or cleaned and/or surface treated, and in a second step at least one free-standing preformed abradable coating element (18) or a complete abradable coating system is attached to the component (9), preferably by using a matrix, wherein for example only a center part (2) or a fraction of a center part (2) is replaced.
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Citations
28 Claims
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1. An abradable coating system for clearance reduction in a turbine or a compressor, the turbine or compressor defining an axis of rotation and having blading and a component on which said system can be applied, the system comprising:
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at least one block, wherein the block comprises; a woven or non-woven tissue or foam made of a material selected from the group consisting of ceramic, glass, glass-ceramic, ceramic-metal composite, and combinations thereof, and filler particles, filler fibers, an inorganic polymer binder, or combinations thereof, at least partially filling the tissue or foam; a center part, wherein at least the center part of the system has an abradability which is graded along a radial direction with respect to the axis of rotation, such that the surface region of a side facing the blading is more abradable than an opposite side facing the component, wherein the center part is stripe-like and circumferentially oriented, wherein the center part is highly abradable such that it can be abraded by the blading; a pair of stripe-like, circumferentially oriented side parts immediately axially adjacent to the center part, wherein the side parts are less abradable than the center part; and wherein an abradable differentiation between the center part and the side parts is achieved by using a different impregnation matrix material for the center part and the side parts. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for the preparation of an abradable coating system on a turbine or compressor component, the turbine or compressor defining an axis of rotation and having blading and a component on which said system can be applied, and wherein the abradable coating system includes a center part having an abradability which is graded along a radial direction with respect to the axis of rotation, such that the surface region of a side facing the blading is more abradable than an opposite side facing the component, wherein the center part is stripe-like and circumferentially oriented, and a pair of stripe-like, circumferentially oriented side parts immediately axially adjacent to the center part, the method comprising:
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(A1) first attaching a woven or non-woven tissue or foam made of a material selected from the group consisting of ceramic, glass, glass-ceramic, ceramic-metal composite, and combinations thereof, to the component or to a previous tissue or foam with a matrix, and (A2) second impregnating the woven or non-woven tissue or foam with filler particles or fibers formed of a material selected from the group consisting of oxide precursor, oxide, and combinations thereof, with a binder of organic or inorganic polymer, or with both;
or(B1) first impregnating a woven or non-woven tissue or foam made of a material selected from the group consisting of ceramic, glass, glass-ceramic, ceramic-metal composite, and combinations thereof, with filler particles or fibers selected from the group consisting of oxide precursor, oxide, and combinations thereof, with a binder selected formed from organic or inorganic polymer, or with both, and optionally pre-sintering, to form a matrix impregnated tissue, and (B2) second attaching the matrix impregnated tissue to the component or the previous tissue or foam with a matrix, (C) third heat treating the abradable coating system after (A2) or (B2), and (D) producing an abradable differentiation between the center part and the side parts either before or after heat treating the abradable coating system, wherein the center part is highly abradable such that it can be abraded by the blading, and the side parts are less abradable than the center part; and achieving the abradable differentiation between the center part and the side parts by using a different impregnation matrix material for the center part and the side parts. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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Specification