Coating comprising MCrAl-X coating layer

Abstract

Coated substrate comprising a substrate (1) comprising a metal substrate surface (11) coated with a coating system (7) consisting of or comprising a functional coating film (5), said functional coating film (5) consisting of or comprising at least one MCr Al—X coating layer, whereas ° the at least one MCr Al—X coating layer is deposited directly on the metal substrate (11), or ° the at least one MCr Al—X coating layer is deposited on an intermediate coating layer (3) that is formed of at least one substrate matching layer (31), wherein the at least one substrate matching layer (31) is deposited directly on the metal substrate surface (11), wherein the layer deposited directly on the metal substrate surface (11), it means respectively the MCr Al—X coating layer if it is deposited directly on the metal substrate surface (11) or the substrate matching layer (31) if it is deposited on the metal substrate surface (11) exhibits: ° epitaxial growth in part or totally, or ° heteroepitaxial growth in part or totally.

Claims

1. A coated substrate comprising a substrate having a metal substrate surface coated with a coating system consisting of or comprising a functional coating film, said functional coating film consisting of or comprising at least one MCrAI-X coating layer, wherein the MCrAI-X coating layer comprises at least two sublayers, a first sublayer and a second sublayer, wherein the first sublayer is deposited nearest to the metal substrate surface and the second sublayer is deposited onto the first sublayer, wherein both the first sublayer and the second sublayer comprise the same elements but the second sublayer has a higher Al content than the first sublayer, and the second sublayer comprises oxygen and is therefore a MCrAI-X-0 layer, wherein the at least one MCrAI-X coating layer is deposited directly on the metal substrate surface, or the at least one MCrAI-X coating layer is deposited on an intermediate coating layer that is formed of at least one substrate matching layer, wherein the at least one substrate matching layer is deposited directly on the metal substrate surface, wherein the layer deposited directly on the metal substrate surface means respectively the MCrAI-X coating layer if it is deposited directly on the metal substrate surface or the substrate matching layer if it is deposited directly on the metal substrate surface exhibits: epitaxial growth in part or totally, or heteroepitaxial growth in part or totally.

2. The coated substrate according to claim 1, wherein the metal substrate surface is a super alloy or a nickel aluminide.

3. The coated substrate according to claim 2, wherein the metal substrate surface is a super alloy of the type nickel-based super alloy or cobalt-based super alloy or a nickel/cobalt-based super alloy.

4. The coated substrate according to claim 1, wherein a concentration of Al in the second sublayer in relation to the first sublayer taking into account only a concentration of metallic components M, Cr and Al in atomic percentage is twice as much.

5. The coated substrate according to claim 1, wherein the oxygen in the second sublayer increases gradually.

6. The coated substrate according to claim 1, wherein aluminum in the second sublayer increases gradually.

7. The coated substrate according to claim 1, wherein at least one layer of MCrAI-X material is present in the functional coating film, and the at least one layer of MCrAI-X material exhibits fcc crystalline structure.

8. The coated substrate according to claim 1, wherein the layer that is deposited directly on the metal substrate surface has a similar crystalline structure compared to a crystalline structure of the material of the metal substrate, respectively of the metal substrate surface, wherein a maximal mismatch in a lattice parameter is of 5%.

9. A method for producing the coated substrate according to claim 1, comprising depositing the at least one layer of the type MCrAI-X by using a physical vapor deposition (PVD) technique, wherein the PVD technique is arc evaporation or magnetron sputtering, and wherein a target composed of M, Cr, Al and X is used as coating source material.

10. The method according to claim 9, wherein the magnetron sputtering technique is a high power impulse magnetron sputtering (HiPIMS) technique.

11. A coated substrate comprising a substrate having a metal substrate surface coated with a coating system consisting of or comprising a functional coating film, said functional coating film consisting of or comprising at least one MCrAI-X coating layer, wherein the at least one MCrAI-X coating layer is deposited directly on the metal substrate surface, or the at least one MCrAI-X coating layer is deposited on an intermediate coating layer that is formed of at least one substrate matching layer, wherein the at least one substrate matching layer is deposited directly on the metal substrate surface, wherein the layer deposited directly on the metal substrate surface means respectively the MCrAI-X coating layer if it is deposited directly on the metal substrate surface or the substrate matching layer if it is deposited directly on the metal substrate surface exhibits: epitaxial growth in part or totally, or heteroepitaxial growth in part or totally; and wherein the functional coating film further comprises at least one layer of MCrAI-X-O material, and in the MCrAI—X layer and also in the MCrAI-X-O material: M is Ni or Co or Ni-Co, and X is Y or Er or Zr.

12. The coated substrate according to claim 11, wherein at least one layer of MCrAI-X-O material present in the functional coating film has an indentation hardness (HIT)— measured by using nanoindentation techniques—in a range between 18 GPa and 35 GPa+/−2 GPa, the range including the border values 18 GPa and 35 GPa.

13. The coated substrate according to claim 11, wherein at least one layer of MCrAI-X material present in the functional coating film has an indentation hardness (HIT)— measured by using nanoindentation techniques—of 9 GPa+/−2 GPa.

14. The coated substrate according to claim 11, wherein at least one layer of MCrAI-X-O material present in the functional coating film has an elastic modulus (EIT)— measured by using nanoindentation techniques—in a range between 270 GPa and 320 GPa+/−5 GPa, the range including border values 270 GPa and 320 GPa.

15. The coated substrate according to claim 11, wherein at least one layer of MCrAI-X material present in the functional coating film has an elastic modulus (EIT)— measured by using nanoindentation techniques—of 220 GPa+/−5 GPa.

16. The coated substrate according to claim 11, wherein at least one layer of MCrAI-X-O material is present in the functional coating film, wherein the at least one layer of MCrAI-X-O material comprises an oxygen content corresponding to a value in a range between 50 at. % and 60 at. %+/−3at. %— the range including border values 50 at. % and 60 at. %— considering all elements present in the at least one layer of MCrAI-X-O material for determining element composition in atomic percentage.

17. The coated substrate according to claim 16, wherein the oxygen content corresponds to a value higher than 50 at. % and up to and including 60 at. %.

18. The coated substrate according to claim 16, wherein the oxygen content corresponds to a value in a range from 50 at. % up to lower than 60 at. %.

19. A coated substrate comprising at least one metal substrate surface coated with a coating system comprising a functional coating film and an intermediate coating film deposited between the at least one metal substrate surface and the functional coating film, wherein the functional coating film comprises at least one layer of the type MCrAl X and at least one layer of the type MCrAI-X-O and the intermediate coating film, wherein the at least one layer of the type MCrAI-X and/or the at least one layer of the type MCrAI-X-O is deposited directly on the at least one metal substrate surface using arc evaporation or magnetron sputtering.

20. A method for producing the coated substrate according to claim 19, comprising depositing the at least one layer of the type MCrAI-X and/or the at least one layer of the type MCrAI-X-O using a physical vapor deposition (PVD) technique, wherein the PVD technique is arc evaporation or magnetron sputtering, and wherein a target composed of M, Cr, Al and X is used as a coating source material and in case of deposition of at least one layer of the type MCrAI-X-O, oxygen flow gas is used as reactive gas.

Description

DESCRIPTION OF THE FIGURES

(1) FIGS. 1a, 1b and 1c show schematically different architectures of a coating system deposited on a substrate according to the present invention.

(2) FIG. 2 shows an example of a coating architecture according to a further preferred embodiment of the present invention, in which the intermediate coating film 3 comprises a first layer of Cr deposited directly on the surface 11 of the substrate 1 and a second layer of Al—Cr deposited on the first layer. Furthermore, the functional coating film 5 is deposited on the intermediate coating film 3 and comprises a multilayered film comprising MCrAl—X layers and MCrAl—X-O layers deposited alternate one on each other.

(3) FIG. 3 shows a SEM-micrograph of a MCrAl—X layer deposited directly on the substrate—Oxygen flow: 0 sccm

(4) FIG. 4 shows a SEM-micrograph of a MCrAl—X-O layer deposited directly on the substrate—Oxygen flow: 800 sccm

(5) FIG. 5 shows a SEM-micrograph of a MCrAl—X-O layer deposited directly on the substrate—Oxygen flow: 100 sccm

(6) FIG. 6 shows a SEM-micrograph of a MCrAl—X/MCrAl—X-O layer deposited directly on the substrate—At the beginning the oxygen flow was set at 0 sccm for the deposition of the MCrAl—X layer, following the oxygen flow was set at 200 sccm for the deposition of the MCrAl—X-O layer

(7) FIGS. 7-9 show advantageous coating system architectures for producing coated substrates according to the present invention.

(8) FIG. 10 shows the crystal orientation mapping based on EBSD of a cross-section of the interface of the NiCrAlY layer deposited on a single crystalline superalloy substrate 1 (PWA1483SX). The interface is marked by a dashed line. The regions of heteroepitaxial growth (coherency) of the layer with respect to the substrate are marked with circles. These regions confirm an in part heteroepitaxial growth (it means a local heteroepitaxial growth) of the MCrAl—X layer deposited directly on the metal substrate surface. A local epitaxial or heteroepitaxial growth should have preferably a thickness (in the coating thickness direction) of at least 100 nm, more preferably higher than 500 nm for attaining a more stable interface between substrate surface and MCrAl—X coating layer.

(9) FIG. 11 shows Table 1 comprising examples of elemental compositions in wt. % of two superalloy substrates (Superalloy 1, Superalloy 2) and three MCrAl—X coating layers (NiCrAlY 1, NiCrAlY 2 and NiCrAlY 3).

(10) Concretely, the present invention relates to:

(11) A coated substrate comprising a substrate (1) comprising a metal substrate surface (11) coated with a coating system (7) consisting of or comprising a functional coating film (5), said functional coating film (5) consisting of or comprising at least one MCrAl—X coating layer, wherein: the at least one MCrAl—X coating layer is deposited directly on the metal substrate (11), or the at least one MCrAl—X coating layer is deposited on an intermediate coating layer (3) that is formed of at least one substrate matching layer (31), wherein the at least one substrate matching layer (31) is deposited directly on the metal substrate surface (11),
and wherein the layer deposited directly on the metal substrate surface (11), it means respectively the MCrAl—X coating layer if it is deposited directly on the metal substrate surface (11) or the substrate matching layer (31) if it is deposited on the metal substrate surface (11) exhibits: epitaxial growth in part or totally, or heteroepitaxial growth in part or totally.

(12) Preferably the material of the metal substrate surface (11) is a super alloy or a nickel aluminide.

(13) Preferably the metal substrate surface (11) is a super alloy of the type nickel based super alloy or cobalt based super alloy or a nickel/cobalt based super alloy.

(14) According to a preferred embodiment of the present invention the MCrAl—X coating layer comprises at least two sublayers, a first sublayer and a second sublayer, wherein the first sublayer is deposited nearest to the metal substrate surface (11) and the second sublayer is deposited onto the first sublayer, wherein the both the first sublayer and the second sublayer comprises the same elements but the second sublayer has a higher Al content than the first sublayer.

(15) Preferably the MCrAl—X layer comprises at least two sublayers, a first sublayer and a second sublayer, wherein the second layer comprises oxygen and is therefore a MCrAl—X-O layer.

(16) Preferably the concentration of Al in the second sublayer in relation to the first sublayer taking into account only the concentration of the metallic components M, Cr and Al in atomic percentage is twice as much.

(17) The oxygen in the second sublayer can increase gradually.

(18) The aluminum in the second sublayer can also increase gradually.

(19) Preferably in the MCrAl—X layer, and if present then also in the MCrAl—X-O material: M is Ni or Co or Ni—Co, and X is Y or Er or Zr.

(20) According to a preferred embodiment of the present invention at least one layer of MCrAl—X-O material present in the functional coating film (5) has indentation hardness (HIT)—measured by using nanoindentation techniques—in the range between 18 GPa and 35 GPa+/−2 GPa, the range including the border values 18 GPa and 35 GPa.

(21) Preferably at least one layer of MCrAl—X material present in the functional coating film (5) has indentation hardness (HIT)—measured by using nanoindentation techniques—of 9 GPa+/−2 GPa.

(22) Preferably at least one layer of MCrAl—X-O material present in the functional coating film (5) has elastic modulus (EIT)—measured by using nanoindentation techniques—in the range between 270 GPa and 320 GPa+/−5 GPa, the range including the border values 270 GPa and 320 GPa.

(23) Preferably at least one layer of MCrAl—X material present in the functional coating film (5) has elastic modulus (EIT)—measured by using nanoindentation techniques—of 220 GPa+/−5 GPa.

(24) According to a preferred embodiment of the present invention, in which at least one layer of MCrAl—X-O material is present in the functional coating film (5), this layer comprises an oxygen content corresponding to a value between 50 at. % and 60 at. %+/−3 at. %—the range including the border values 50 at. % and 60 at. %—considering all elements present in this layer for the determination of the element composition in atomic percentage.

(25) Preferably the oxygen content corresponds to a value higher than 50 at. %.

(26) Preferably the oxygen content corresponds to a value lower than 60 at. %.

(27) According to a preferred embodiment of the present invention at least one layer of MCrAl—X material is present in the functional coating film (5), wherein this layer exhibits fcc crystalline structure.

(28) A preferred method for producing a coated substrate according to any of the embodiments mentioned above, comprises a step in which the at least one layer of the type MCrAl—X is deposited by using a physical vapor deposition (PVD) technique, wherein the used PVD technique is arc evaporation or magnetron sputtering, and wherein a target composed of M, Cr, Al and X is used as coating source material and in case of deposition of at least one layer of the type MCrAl—X-O, oxygen flow gas is used as reactive gas.

(29) The deposition method for depositing the at least one layer of the type MCrAl—X coating layer can be a magnetron sputtering technique of the type high power impulse magnetron sputtering (HiPIMS).

(30) According to a preferred embodiment of the present invention, the layer that is deposited directly on the metal substrate surface (11) has a similar crystalline structure compared to the crystalline structure of the material of the metal substrate (1), respectively of the metal substrate surface (11), wherein the maximal mismatch in the lattice parameter is of 5%, preferably maximal 1%.

(31) The present invention relates also to coated substrates comprising at least one metal substrate surface (11) coated with a coating system (7) comprising a functional coating film (5) and an intermediate coating film (3) deposited between the at least one metal surface (11) and the functional coating film (5), wherein the functional coating film (5) comprises at least one layer of the type MCrAl—X and/or at least one layer of the type MCrAl—X-O and the intermediate coating film (3), wherein the at least one layer of the type MCrAl—X and/or the at least one layer of the type MCrAl—X-O is deposited by means of arc evaporation or magnetron sputtering, if sputtering preferably HiPIMS, directly on the at least one metal surface (11).

(32) A preferred method for producing a coated substrate according the directly above described embodiment, comprises a step in which the at least one layer of the type MCrAl—X is deposited by the at least one layer of the type MCrAl—X and/or the at least one layer of the type MCrAl—X-O is deposited by using a physical vapor deposition (PVD) technique, wherein the used PVD technique is arc evaporation or magnetron sputtering, if sputtering preferably HiPIMS, wherein a target composed of M, Cr, Al and X is used as coating source material and in case of deposition of at least one layer of the type MCrAl—X-O, oxygen flow gas is used as reactive gas.

(33) For the PVD deposition of the MCrAl—X and MCrAl—X-O layers as described in the present invention usual coating parameters can be used.

(34) For example, for the deposition of a MCrAl—X coating layer by using arc evaporation PVD techniques and a target composed of M. Cr, Al and X as described above, the arc current can be adjusted to be in a typical range or arc current for such kind of PVD processes, for example a value between 100 A and 200 A. The substrate temperature during deposition can be also adjusted to be in known substrate temperature ranges, for example between 200° C. and 800° C. or between 400° C. and 600° C.

(35) Before coating deposition, the substrate surfaces to be coated should be/can be cleaned and pre-treated in known manner (e.g. by using known cleaning processes and plasma pretreatment processes).