ANTI-CORROSION AND ANTI-EROSION PROTECTIVE LAYER CONTAINING ALUMINIUM
The corrosion and also the erosion properties of a layer system can be improved by using deposition-hardened particles.
The invention relates to an aluminum-containing protective layer to protect against corrosion and erosion.
Compressor blades of stationary GTs and aircraft turbines are usually produced on the basis of heat-treated martensitic 12%-13% Cr steels and sometimes of precipitation-hardened 16%-17% Cr steels. As protection against corrosion, the blades of the front stages are protected by means of a special aluminum pigment-containing high-temperature surface coating.
The disadvantage of this coating is the relatively low erosion resistance of the layer. As a consequence thereof, not only a very complicated filtering of the air but often also a regular recoating of the blades (in the course of refurbishment) are necessary.
To solve this problem, the protective layers used to date are inspected at regular intervals for erosion damage and corrosion protection and in the course of refurbishment removal of the coating with subsequent recoating of the blades with the same system are carried out. The length of these time intervals is greatly dependent on the ambient air and the effectiveness of filter devices.
This problem is to be solved.
The object is achieved by a layer system as claimed in claim 1.
The refurbishment intervals could be lengthened by increasing the erosion resistance of the coating.
In the dependent claims, further advantageous measures which can be combined with one another in any way to achieve further advantages are listed.
The figures and the description present only examples of the invention.
Preference is given to the harder aluminum-containing particles AL* in a layer 7′ (
The single layer 7″ can, proceeding from
This likewise applies to a single layer 7′″ as per
To increase the erosion resistance, proceeding from
A further example of the invention comprises introducing aluminum into both layers (
Depending on the field of application, hard material particles H can be incorporated in the lower layers 7″ and 7″′ and in the upper layer 10′, 10″ as per
In addition, the upper layer can be provided with soft aluminum particles Al, harder, aluminum-containing particles AL* and/or hard material particles H or the upper layer 10IV can comprise only soft aluminum particles composed of aluminum or the upper layer 10V comprises both hard material particles H and relatively hard aluminum-containing particles AL*.
In
In
In
Proceeding from
In
The hardest erosion protection is formed by an upper layer 10V in which relatively hard aluminum particles AL* and hard material particles are present, with, depending on the field of application and degree of erosion protection, relatively hard aluminum particles AL* being present in the lower layer 7′ (
In
In
In
In less erosive environments, the upper layer 10IV can, in comparison to
In particular, the outer layer is protected against erosion by the upper layer 10V comprising aluminum-containing relatively hard particles AL* and hard material particles H (
In
As hard material particles H, it is possible to use ceramic particles, preferably aluminum nitride and boron nitride, chromium carbide, aluminum oxide or mixtures thereof.
The substrate 4 (
The increase according to the invention in erosion protection is achieved by use of relatively hard, aluminum-containing particles AL* composed of an aluminum alloy, in particular a precipitation-hardened aluminum alloy, which has a 5-10-fold greater hardness and a strength which is higher by a factor of at least 5.
As precipitation-hardening alloys composed of aluminum and at least one element from the group consisting of Zn, Mg, Cu, Mn, Co, preference is given to using, in particular, the following alloys: Al—Zn, Al—Zn—Mn, Al—Mn—SC, Al—Mg—Mn, Al—Mg—Zn—Cu, Al—Cu—Mn—Zn, AlZn4.5Mg1, AlZnMgCu1.5, AlZnMgCu0.5, AlMg4.5Mn.
However, it is also possible to employ alloys having significantly higher contents of various alloying elements, e.g. having 6%-8% of zinc (Zn).
Preference is likewise given to using:
-
- particles AL* composed of aluminum composites made up of aluminum or an aluminum alloy as matrix: Al—Si, Al—Si—Mg, Al—Mn, Al—Fe, Al—Ni, Al—Zn with an incorporated second component such as ceramic particles composed of Al2O3 or SiC,
- dispersion-hardening aluminum materials comprising oxides, carbides or nitrides (Al2O3, Al4C3), comprising lithium (Li) or using intermetallic phases: AlFe83Co, AlFe8Ce4, AlFe8Zr1,
- aluminides: in particular NiAl, Ni3Al, FeAl, Fe3Al, TiAl, Ti3Al,
- precipitation-hardening scandium-containing (Sc) aluminum alloys Al—Sc or Al—Sc—X alloys.
After baking of the aluminum pigment layer, a conductivity blasting with low intensity is generally carried out. Targeted pressure blasting using optimized parameters enables a high increase of aluminum particles to be additionally achieved.
The matrix material of the layers 7, 7′, 7″, 7″′, 10, 10′, 10″, 10″′, 10IV, 10V (
Claims
1. A layer system which comprises at least: aluminum-zinc-manganese (Al—Zn—Mn); aluminum-manganese-scandium (Al—Mn—Sc); aluminum-magnesium-manganese (Al—Mg—Mn); aluminum-magnesium-zinc-copper (Al—Mg—Zn—Cu); aluminum-magnesium-zinc-copper-cobalt (Al—Mg—Zn—Cu—Co); and aluminum-copper-manganese-zinc (Al—Cu—Mn—Zn)
- a substrate;
- a lower layer of a matrix material on the substrate;
- optionally an outer layer of a matrix material on the lower layer;
- wherein particles composed of aluminum (Al) having a soft hardness, are present in the matrix material of at least one of the layers of the layer system;
- at least one of the layers includes in the matrix material thereof aluminum-containing particles (AL*) which are harder than the soft hardness particles composed of aluminum (Al) wherein the aluminum-containing particles (AL*) comprise an aluminum alloy or a precipitation-hardening aluminum alloy having a hardening mechanism, and the precipitation-hardening aluminum-containing particles (AL*) comprise an alloy of aluminum-zinc (Al—Zn);
2. (canceled)
3. The layer system as claimed in claim 1, wherein the aluminum-containing particles (AL*) comprise scandium-containing (Sc) aluminum Al alloys:
- Al—Sc, Al—Cu—Sc, Al—Si—Sc, Al—Mg—Si—Sc, Al—Zn—Mg—Sc, Al—Li—Sc and/or Al—Mg—Sc.
4. The layer system as claimed in claim 1, wherein dispersion-hardening aluminum alloys are used for the aluminum-containing particles (AL*), wherein the aluminum-containing particles (AL*) are produced by mechanical alloying.
5. The layer system as claimed in claim 1, wherein the aluminum-containing particles (AL*) are selected from aluminides NiAl, Ni3Al, FeAl, Fe3Al, TiAl, Ti3Al, AlFe8, AlFe8Co, AlFe8Ce4 and/or AlFe8Zr1.
6. The layer system as claimed in claim 1, wherein the aluminum-containing particles (AL*) comprise aluminum composites selected from:
- aluminum (Al), an aluminum alloy, selected from alloys Al—Si, Al—Si—Mg, Al—Mn, Al—Fe, Al—Mn—Fe, Al—Ni, Al—Zn, and having an incorporated harder ceramic component which includes oxides or nitrides.
7. The layer system as claimed in claim 1, having a lower layer and no outer layer outward of the lower layer; and
- the lower layer having particles of aluminum selected from aluminum alloy and having hard particles not of aluminum.
8. The layer system as claimed in claim 1, which comprises at least:
- only one lower layer; and
- only one outer layer.
9. (canceled)
10. the layer system as claimed in claim 1, further comprising hard material particles (H) or (AL*) present in the lower layer.
11. The layer system as claimed in claim 1, further comprising hard material particles (H) present in the upper layer along with the aluminum particles.
12. The layer system as claimed in claim 1, further comprising hard material particles (H) present in both layers.
13. The layer system as claimed in claim 1, further comprising hard material particles in at least one of the layers and comprising at least one of aluminum nitride, boron nitride, chromium carbide, aluminum oxide or mixtures thereof
14. The layer system as claimed in claim 1, wherein each of the layers or both of the layers are comprised of the same matrix material, in which the particles are included.
15. (canceled)
16. The layer system as claimed in claim 1, wherein the substrate is comprised of a steel.
17. The layer system as claimed in claim 1, wherein the aluminum particles have an increased hardness as a result of production thereof including conductivity blasting.
18. The layer system as claimed in claim 7, wherein the lower layer comprises aluminum particles (Al) having a maximum hardness of Hv50, and the upper layer comprises aluminum particles having an at least 10% greater hardness (AL*), wherein precipitation-hardening aluminum alloy particles (AL*) are in the upper layer.
19. The layer system as claimed in claim 1, wherein the upper layer does not comprise any aluminum-containing particles (AL*) or aluminum particles (Al).
20. The layer system as claimed in claim 1, wherein the lower layer is directly on the substrate.
21. The layer system as claimed in claim 1, wherein the soft hardness of the aluminum particles soft hardness is up to Hv50.
22. The layer system as claimed in claim 1, wherein the alloy includes:
- Al3Li and/or
- AlZn4.5Mg1 and/or
- AlZnMgCu1.5 and/or
- AlZnMgCu0.5 and/or
- AlMg4.5Mn.
23. The layer system as claimed in claim 5, wherein the harder ceramic component includes Al2O3, Al4C3 and/or SiC
24. The layer system as claimed in claim 17, wherein the conductivity blasting comprises cold strengthening processes, particle blasting or rolling.
25. A layer system comprising:
- a substrate;
- a lower covering layer on the substrate made of a first matrix material;
- an outer layer on the lower layer and made of a second matrix material;
- the outer layer includes in the second matrix material of the outer layer at least one of aluminum particles and hard aluminum particles and the outer layer optionally includes hard particles not of aluminum.
26. The layer system as claimed in claim 2, wherein the lower layer includes at least one of particles of aluminum, hard aluminum and hard particles not of aluminum.
Type: Application
Filed: Mar 27, 2013
Publication Date: Mar 19, 2015
Inventors: Jochen Barnikel (Mulheim an der Ruhr), Andrei Ghicov (Mulheim an der Ruhr), Friedhelm Schmitz (Dinslaken)
Application Number: 14/391,903
International Classification: F01D 5/28 (20060101); C22C 21/10 (20060101); C22C 21/08 (20060101); C22C 21/06 (20060101); C22C 21/18 (20060101); C22C 21/02 (20060101); C23F 11/18 (20060101); C22C 21/00 (20060101);