SURFACE ROUGHENING OF CMC AND COATED CMC

Abstract

By surface roughening of CMC component via a pico-laser treatment a good adhering of a plasma sprayed coating is achieved.

Claims

1. A method of roughening a surface of a CMC substrate of a CMC component, wherein a pico-laser with pulses in the pico-second area is used to roughen or engrave the surface of the CMC substrate.

2. The method according to claim 1, wherein holes, including at least one of round holes, engravings, and grids are produced into the surface of the CMC substrate.

3. A product, produced by a method according to claim 1, which has a ceramic layer on a roughened surface of a substrate, wherein the ceramic layer has a APS applied-like microstructure.

4. The product according to claim 3, wherein the material of the ceramic layer comprises zirconia, 8YSZ, alumina, 48YSZ or a 48YSZ-alumina mixture.

5. The product according to claim 3, wherein the surface of the substrate under the ceramic layer comprises holes, especially including at least one of round holes, elongated engravings, and grids.

6. The product according to claim 5, wherein the depth of the holes 10, engravings or grids are between 50 m to 100 m.

Description

BRIEF DESCRIPTION

[0012] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0013] The FIG. 1 shows a CMC component 1 which comprises a CMC substrate 4 with a surface 5.

DETAILED DESCRIPTION

[0014] The substrate 4 is made of a CMC, of an Ox-Ox-CMC, but not limited.

[0015] As described above the surface 5 of the CMC-substrate 4 is roughened or structured by a pico-laser, which leads to no melting of the material of the CMC. Pulses in the pico-second region are used, especially max 900 ps.

[0016] The surface 5 of the CMC-substrate 4 can comprise holes 10 (FIG. 2), especially round holes, elongated engravings 13, 16 (FIG. 3), which can be straight 13 or waved 16 or grids 11 (FIG. 4). These forms 10, 13, 16, 11 can appear alone or in combination with each other in the surface 5.

[0017] An alternative is to randomly remove locally material from the surface to roughen the surface 5 deeper and additionally (FIG. 5).

[0018] Especially a depth of 50 m to 100 m is at least given for the holes 10, engravings 13, 16 or grids 11.

[0019] After that a ceramic layer 7 is applied on which is performed by APS.

[0020] The material of the ceramic layer 7 is zirconia (ZrO.sub.2), stabilized zirconia 8YSZ and/or an alumina sublayer, or alumina or 48YSZ (fully stabilized zirkonia).

[0021] Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

[0022] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.