WO2015080804A1 - Modified thermal barrier composite coatings - Google Patents
Modified thermal barrier composite coatings Download PDFInfo
- Publication number
- WO2015080804A1 WO2015080804A1 PCT/US2014/060104 US2014060104W WO2015080804A1 WO 2015080804 A1 WO2015080804 A1 WO 2015080804A1 US 2014060104 W US2014060104 W US 2014060104W WO 2015080804 A1 WO2015080804 A1 WO 2015080804A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- coating
- coating layer
- layer
- thermal barrier
- modified composite
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
- F01D5/288—Protective coatings for blades
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
- C23C28/042—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
- C23C28/048—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material with layers graded in composition or physical properties
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/10—Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
- C23C4/11—Oxides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/134—Plasma spraying
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
- Y10T428/24612—Composite web or sheet
Definitions
- the present invention relates generally to the field of thermal barrier composite coatings utilized to protect substrate materials from high temperature and corrosive environments.
- TBC's Thermal barrier coatings
- TBC's can be deposited by vapor processes, such as physical vapor deposition (PVD).
- PVD coatings typically are produced from process conditions designed to foster nucleation and growth of discrete, tightly packed, columnar grains which provides a compliant microstructure.
- the columnar grains are separated by small gaps that can relieve the stress in the coating.
- the gaps between the columns can provide pathways for penetration of contaminants which can induce corrosion of the underlying coating and/or substrate material.
- thermal barrier coatings can be applied by atmospheric plasma spray (APS) which are derived from a dry powder source.
- APS coatings are formed by heating a gas-propelled spray of a powdered metal oxide or non-oxide material with a plasma spray torch. The spray is heated to a temperature at which the powder particles become molten. The spray of molten particle is directed against a substrate surface where they solidify upon impact to create a coating.
- the conventional as-deposited APS microstructure is known to be characterized by overlapping splats of material. The inter-splat boundaries can be tightly joined or may be separated by gaps resulting in some porosity.
- APS coatings are generally less expensive to apply than EB-PVD coatings and they provide a better thermal and chemical seal against the surrounding environment than columnar-grained structures.
- the inter- splat gaps in the as- deposited APS microstructure tend to densify upon exposure to high temperatures. Such densification may result in a shorter operating life in a gas turbine environment by virtue of repeated thermal cycling inducing accumulation of thermal stresses within the coating that can ultimately cause spallation.
- a columnar structure may be produced by using an APS process (i.e., spray process performed under ambient temperature and pressure conditions) utilizing nano-sized powder commonly delivered by solution or suspension means.
- APS process i.e., spray process performed under ambient temperature and pressure conditions
- nano-sized powder commonly delivered by solution or suspension means.
- the inter-columnar gaps can provide strain relief.
- the plasma effluent and the particle size are tailored to a desired interaction range, the overlapping layers of deposited material can flow together to form a columnar ordering of the adjacent particle layers.
- the invention may include any of the following aspects in various combinations and may also include any other aspect of the present invention described below in the written descriptioa
- a thermal barrier modified composite coating comprising: a first coating layer bonded to a surface of a substrate, said first coating layer comprising macro columnar features characterized by a predetermined distribution of peaks and valleys at their corresponding free surfaces to create improved mechanical bonding between the first layer and a second layer; said macro columnar features derived from a precursor liquid suspension of nano-sized and/or submicron-sized splats to form a thermo- mechanical compliant interface at the substrate surface, said splats being randomly oriented to produce an isotropic crystallographic orientation for the first coating; said splats comprising non-equiaxed columnar grains that grow opposite to a direction of heat flow upon cooling to produce an anisotropic crystallographic grain orientation;
- a thermal barrier modified composite coating comprising: a first coating layer bonded to a surface of a smooth substrate, said first coating layer having a size less than about 10 ⁇ ; said first coating layer comprising macro columnar features characterized by a
- said macro columnar features derived from a precursor liquid suspension of nano-sized and/or submicron-sized splats to form a
- thermomechanical compliant interface at the substrate surface said splats being randomly oriented to produce an isotropic crystallographic orientation for the first coating; said splats comprising non-equiaxed columnar grains that grow opposite to a direction of heat flow upon cooling to produce an anisotropic crystallographic grain orientation; and said second layer comprising a densified coating layer bonded to the corresponding free surfaces of the first coating layer, said densified coating having a lower porosity than that of the first coating layer, said densified coating having an improved mechanical erosion barrier in comparison to the first coating layer.
- a thermal barrier modified composite coating comprising: a first coating layer bonded to a surface of a smooth substrate, said first coating layer having a size less than about 10 ⁇ ; said first coating layer comprising macro columnar features characterized by a
- said macro columnar features derived from a precursor liquid suspension of nano-sized and/or submicron-sized splats to form a
- thermomechanical compliant interface at the substrate surface said splats being randomly oriented to produce an isotropic crystallographic orientation for the first coating; said splats comprising non-equiaxed columnar grains that grow opposite to a direction of heat flow upon cooling to produce an anisotropic crystallographic grain orientation; said second layer comprising a densified coating layer bonded to the corresponding free surfaces of the first coating layer, said densified coating having a lower porosity than that of the first coating layer, said densified coating derived from a dry powder applied by atmospheric spraying, said coating comprising partially molten and fully molten particles having an improved mechanical erosion barrier in comparison to the first coating layer.
- Figure la shows an optical micrograph of a representative first coating layer of the present invention having columnar grained macrostructures
- Figure lb shows an optical micrograph of the columnar grained coating of Fig. la at a higher magnification
- Figure 2 generally illustrates any suitable second coating layer that can be bonded to the free surfaces of the first coating layer of Figures la and lb;
- Figure 3 illustrates an exemplary composite coating system in accordance with an embodiment of the present invention in which the second coating layer is a dense columnar coating
- Figure 4 illustrates an exemplary composite coating system in accordance with another embodiment of the present invention, in which the second coating layer is a environmental barrier coating;
- Figure 5 illustrates an exemplary composite coating system in accordance with yet another embodiment of the present invention, in which the second coating layer is a DVC;
- Figure 6 illustrates an exemplary composite coating system in accordance with yet another embodiment of the present invention, in which the second coating layer is an abradable coating;
- Figure 7 shows an optical micrograph of a columnar composite coating system that was prepared in accordance with the principles of the present invention
- Figure 8 shows an optical micrograph for another columnar composite coating system that was prepared in accordance with the principles of the present invention
- Figure 10 plots and compares the results of various mechanical erosion resistance tests for different thermal barrier coating materials.
- the present disclosure relates to novel TBC composite coatings for a variety of applications.
- the coatings of the present invention are particularly suitable for high-temperature applications, including, but not limited to gas turbines.
- the disclosure is set out herein in various embodiments and with reference to various aspects and features of the invention.
- TBC's of the present invention can achieve improved performance, in relation to other types of materials, including conventional thermal barrier materials. Unless indicated otherwise, it should be understood that all compositions are expressed as weight percentages (wt %) based on the total weight of the formulation.
- the TBC's of the present invention offer unique alternatives to conventional TBC's.
- the TBC's of the present invention include a first and a second layer which are selected to be compatible with each other so as to interact with each another in a synergistic manner to create and maintain superior thermomechanical compliance in terms of adhesion and bond strength at the coating-substrate interface while simultaneously improving selected coating properties in the bulk and/or free surface of the composite coating structure.
- thermomechanical compliance as used herein and throughout the specification is intended to refer to the ability of the first coating layer to maintain sufficient adhesion and bond strength to the substrate surface during repetitive thermal heating and cooling (i.e., "thermal cycling") so as to not undergo spallation from thermal shock impact that can be created by thermal cycling that occurs during use of the coated substrates in high temperature environments, such as, for example, gas turbine applications.
- thermal cycling repetitive thermal heating and cooling
- the composite coating structure is tailored to have one or more selected properties that may vary continuously within each of the first and/or second layers or in a discrete manner from a location within the first coating layer to a location within the second coating layer.
- the selected bulk properties may include, for example, bond strength, thermal conductivity, erosion resistance, corrosion resistance, and thermomechanical compliance.
- Exemplary first coating layers are shown in Figures la and lb.
- Figure la shows an optical micrograph of a representative first coating layer 100 of the present invention having macro columnar features
- Figure lb is an optical micrograph that shows the first coating layer 100 at higher magnification.
- Figures la and lb show the first coating layer 100 bonded to a substrate 110.
- the first coating layer 100 serves as an undercoat for a second coating layer to be deposited thereon in the formation of a composite coating system.
- first coating layer and “undercoat layer” will be used interchangeably throughout the specification.
- Figures la and lb show the first coating layer 100 has macro columnar features 120.
- the macro columnar features 120 are comprised of microstructural features that include nano and/or sub-micron sized splats derived from a precursor liquid suspension of nano-sized and/or submicron sized precursor particles.
- liquid suspension as used herein is intended to refer to a suspension plasma spray (SPS) whereby fine particles as described herein can be effectively suspended and transported to the target substrate without substantial agglomeration to produce a coating.
- SPS suspension plasma spray
- the majority of the precursor material are preferably splats which are partially molten and/or fully molten prior to impinging on the substrate 110. Any resultant particles that re-solidify prior to impacting the substrate 110 tend to become entrapped and lodged within the surrounding splats.
- the splats are randomly oriented to produce an isotropic crystallographic orientation in the first coating or undercoat layer 100.
- the portion of the splats bonded to the surface of the substrate 110 forms a thermomechanical compliant interface that can remain adhered to the surface during thermal cycling conditions typically encountered by TBC's.
- Figures la and lb further show that a controlled amount of porosity is built-in between adjacently configured macro columnar features 120 as well as within the macro columnar features 120.
- the built-in porosity of the columnar undercoat layer 100 can further improve thermomechanical compliance during thermal cycling. As a result, the undercoat layer 100 can aid in extending the lifetime of the inventive TBC in comparison to conventional TBC's.
- Figures la and lb show that the macro-columnar features 120 of the undercoat layer 100 have a distinctive and unique feature of peaks 130 and valleys 140 along the free surfaces of the first coating layer.
- the term "free surfaces" as used herein in connection with the undercoat layer 100 is intended to refer to that portion of the first coating layer 100 that can bond with a topcoat or second coating layer, as will be discussed. It should be understood that the terms “topcoat layer” and “second coating layer” will be used interchangeably throughout the specification.
- the peaks 130 and valleys 140 can be better seen in the higher magnification of Figure lb. Without being bound by any theory, it is believed that the peaks 130 and valleys 140 enhance the properties of the undercoat layer 100 in a manner that creates improved bonding and
- thermomechanical compliance between the undercoat layer 100 and a subsequent topcoat or second coating layer The peaks 130 and valleys 140 can be produced to have a selected distribution and pattern based on control of the thermal spray process and coating media conditions. In a preferred embodiment, the peaks 130 and valleys 140 produce a random- like distribution to create an irregular free surface which is jagged and tortuous, as can be seen in Figure lb.
- the degree of tortuosity of the undercoat layer 100 that is required may depend on several factors, including the end-use application and the type of second coating layer to be bonded thereto. Generally speaking, the tortuosity is sufficient to create a favorable interfacial boundary over which a second coating can be applied and remain adhered thereto during operational use of the composite coating.
- Figures la and lb shows that the width and height of each of the peaks 130 and valleys 140 are substantially non-uniform in order to enhance the tortuosity along the free surface of the first coating layer 100.
- the microstructure of the undercoat is defined by splats and grains contained within the splats.
- the grains are substantially non-equiaxed.
- the grains are produced by undergoing cooling and directional solidification upon making contact with the substrate 110 to produce an anisotropic crystallographic orientation.
- the solidified grains within the splats acquire a directional orientation whereby the grains generally are aligned and grow in a preferred directionality, thereby creating localized texture.
- the fine microstructural features of the undercoat layer 100 may be less than 25 microns ( ⁇ ), and more preferably less than about 10 microns ( ⁇ ) in size to enhance adhesion onto the substrate 110, which can be smooth. In another embodiment, the microstructural features of the undercoat range from about 10 ⁇ down to about 50 nm in size or less.
- a smooth substrate as used herein is intended to mean a surface having a roughness (designated as "Ra") of less than about 125 ⁇ .
- the undercoat layer 100 of the present invention may be applied onto a smooth substrate surface characterized by a Ra between about 25 to about 80 ⁇ . Surface preparation of the substrate surface is therefore not required prior to thermal spraying of the first coating layer 100 onto the substrate 110.
- the first coating layer 100 therefore not only bonds to a smooth substrate surface, but can maintain thermomechanical compliance to the substrate 110 during the severe thermal cycling occurring during its lifetime, thereby extending the lifetime of the coated part such as a gas turbine assembly without requiring repair and/or restoration work.
- the undercoat layer 100 is designed with a controlled amount of built-in porosity to improve thermomechanical compliance during thermal cycling, an extended lifetime of the TBC composite of the present invention in comparison to conventional TBC's can be achieved.
- the built-in porosity in combination with the tortuous interfacial boundary along the free surfaces of the undercoat layer 100 can also enhance insulative properties of the composite coating.
- the undercoat layer 100 by virtue of its relatively small size (i.e., sub-micron or smaller) can be prepared by suspending the precursor material in a liquid carrier during a thermal spray process utilizing a plasma torch to enable effective deposition and coverage of the sub-micron or smaller particles onto the substrate without particle agglomeration as would typically occur if the sub- micron particles were utilized as a dry powder.
- Suitable liquid carriers may include solvents which are aqueous based or fuels.
- suitable solvent materials include, by of example and not intending to be limiting, water, ethanol, methanol, ethylene glycol, kerosene and propylene.
- the exact plasma torch conditions to be selected will be dependent upon several parameters, including the specific type of torch employed and the specific coating media selected for the undercoat and topcoat, as would be recognized by one of ordinary skill in the art.
- thermal barrier precursor materials can be utilized for making the first coating layer 100, such as any suitable ceramic or cermet coating material.
- a ceramic material such as a stabilized zirconia material may be used.
- Other examples include yttria-stabilized zirconia.
- oxides, such as hafnates and cerates can be used along with other oxides that may be stabilized with yttria or other stabilizing agents, such as, for example, ceria.
- the present invention also contemplates zirconium oxide, yttrium oxide, aluminum oxide or any other type of suitable rare earth oxide.
- the columnar grained structure is thermomechanically compliant, it generally cannot on its own create the desired properties of a TBC.
- a second coating layer or topcoat 200 that is compatible with the undercoat layer 100 of Figures la and lb can be bonded thereto to produce a novel TBC composite coating system 220 in accordance with the principles of the present invention.
- the topcoat 200 of Figure 2 is shown not as a micrograph, but rather as an illustration whereby any suitable topcoat 200 can be selected that is complementary and compatible for bonding with the undercoat 100.
- the top coat 200 may be selected as a dense TBC, an abradable coating or any other TBC as will be shown in greater detail in Figures 3-6.
- the tortuous free ends or free surfaces of the undercoat layer 100 provide an effective interfacial boundary 210 for the second coating layer 200 to bond thereto.
- the one or more deficient properties of the first coating layer 100 can be offset or compensated by selection of a suitable second coating layer 200 that is not deficient in the same, thereby improving the overall performance of the TBC composite coating system 200 with respect to that particular deficient property.
- the first coating layer 100 by itself may contain an unacceptably high level of porosity which enhances thermomechanical compliance at the expense of not being able to effectively inhibit heat flow to the surface of the substrate 110.
- the second coating layer 200 can be selected that possesses sufficiently low thermal conductivity relative to the first coating layer 100 so as to balance or offset this particular deficiency in the first coating layer 100. Because the second coating layer 200 may be exposed to the high temperature environment of a component such as a combustion engine, its lower thermal conductivity inhibits heat flow much more effectively than the first coating layer 100. Additionally, the superior compliance of the first coating layer 100 maintains sustained integrity of the composite coating structure 220 in a manner that direct bonding of the second coating layer 200 to the substrate 110 cannot achieve. In other words, the direct bonding of the second coating layer 200 to the smooth or even roughened substrate surface 110 would potentially cause spallation and shorten the operational lifetime of the coated part.
- various types of second coating layers can be applied onto the tortuous interface of the first coating layer.
- selection of the appropriate second coating layer improves the overall bulk and free surface properties of the composite coating system without sacrificing loss of thermocompliance, as will be shown in the Examples.
- Possible composite coatings contemplated by the present invention are shown in Figures 3-6. It should be understood that Figures 3-6 are intended to be illustrative of certain aspects of the composite coating and in the process of doing so may not be representative of the macrostructural and/or microstructural coating morphology of the composite coating system.
- FIG. 3 shows a composite coating system 300 consisting of a densified columnar coating as the second coating layer 320 and a porous columnar coating 310 as the undercoat or first coating layer.
- the densified columnar coating 320 may be applied onto porous columnar undercoat 310 by any suitable process.
- the densified columnar coating 320 is derived from a liquid suspension of particles having a median size greater than that of the median size of the first coating layer 310.
- the densified columnar coating 320 has a higher density and lower porosity than the undercoat layer 310.
- the densified columnar coating 320 provides erosion resistance at its free surface and/or bulk regions.
- the undercoat 310 is the first coating layer and has a columnar structure directly bonded to a smooth substrate 330.
- the columnar undercoat structure 310 is as described in Figs, la and lb.
- the undercoat layer 310 has built-in porosity by virtue of its macro columnar structural features described and shown in Figures la and lb.
- the porous undercoat 310 has greater porosity than the densified columnar coating 320 and therefore provides the requisite thermomechanical compliance to extend the lifetime of the composite coating system 300 in comparison to conventional composite TBC systems.
- the composite coating system 300 of Figure 3 grades the density within the column from across the thickness of the coating.
- the density can be graded in several ways. In one embodiment, the density increases along a path starting at a location within either the first coating layer 310, or adjacent to the interface of the first coating layer 310 and the second coating layer 320, and then extending in a direction towards a point on the free surface of the second coating layer 320.
- the grading can occur in a continuous manner or discrete manner. It should be understood that other coating properties may also be graded.
- the densified columnar coating 320 preferably has a greater thickness than the first coating layer 310 to further enhance erosion resistance properties. This combination of superior thermomechanical compliance provided by the first coating layer 310 and improved coating properties in the bulk and/or free surface provided by the second coating layer 320 produces a compliant composite coating system 300 with superior erosion resistance not previously possible by conventional TBC composite systems.
- Figure 4 shows a composite coating system 400 consisting of an environmental barrier coating (EBC) topcoat 420 as the second coating layer and a porous columnar coating 410 as the undercoat or first coating layer that is bonded to a smooth substrate 430.
- the environmental barrier topcoat 420 blocks pathways for penetration of contaminants therein which can induce corrosion of the substrate surface 430.
- the corrosion resistance of the second coating layer 420 is higher than that of the first coating layer 410.
- the porous columnar coating 410 may be substantially identical to that of the first coating layer 310 of Figure 3.
- the undercoat 410 may be modified at its free surfaces as necessary to produce a customized predetermined distribution of peaks and valleys that can create the desired tortuosity at the interface to allow compatibility with the environmental barrier topcoat 420 so as to facilitate bonding and adhesion of the topcoat 420 thereto.
- Figure 5 shows a composite coating system 500 consisting of a densely vertically cracked (DVC) topcoat 520 as the second coating layer and a porous columnar coating 510 as the undercoat or first coating layer.
- the DVC topcoat 520 utilizes a dense vertically cracked microstructure to create a dense barrier for erosion resistance.
- the DVC topcoat 520 may in some instances serve as an EBC.
- the undercoat 510 is bonded to a smooth substrate 530 and maintains a level of thermomechanical compliance not attainable by the DVC topcoat 520 itself.
- the erosion resistance of the second coating layer 520 is higher than that of the first coating layer 510.
- the first coating layer 510 is relatively more porous and columnar and may be modified at its free surfaces in comparison to that of Figures 3 and 4 to allow compatibility with the DVC topcoat 520 at the bond interface. In this manner, a compliant composite coating system 500 is customized and created with superior erosion resistance not previously possible by conventional TBC composite systems.
- Figure 6 shows a composite coating system 600 consisting of an abradable topcoat 620 as the second coating layer and a porous columnar coating 610 as the undercoat or first coating layer which is bonded to a smooth substrate 630.
- the abradable topcoat 620 is selected to be compatible with the free surfaces of the undercoat 610 at the tortuous interface. During service, the abradable topcoat 620 provides a seal while the columnar undercoat 610 maintains the
- thermomechanical compliance and adhesion In this manner, a compliant composite coating system 600 is created with superior sealant properties not previously possible by conventional TBC composite systems.
- thermomechanical compliance of the modified composite TBC's of the present invention with other materials by conducting furnace cycle tests (FCT's), as will now be discussed in the Examples below.
- FCT's furnace cycle tests
- a smooth Ni based superalloy substrate having a surface roughness Ra of about 25-40 ⁇ was utilized.
- the substrate surface was not pre-roughened, but only lightly burnished to remove any impurities at the free surface prior to coating.
- a fine mesh media was utilized to attain a final surface roughness that was within a surface range of about 25-40 ⁇ .
- a commercially available Progressive Surface 100HETM plasma torch was employed to prepare the SPS undercoats for the Baseline Coatings in Comparative Examples 1 and 2; the SPS undercoat and SPS top coat in Example 1; and the SPS undercoat in Example 2.
- Torch conditions when utilizing the Progressive Surface 100HETM torch to prepare each of such coatings included gas flows and chemistries of 180 scfh argon; 120 scfh nitrogen; and 120 scfh hydrogen.
- the torch was operated at power levels of 100-105 kW and 450-500 Amps.
- the feedrate of the suspension feedstock was about 40-50 mL/min.
- the feedstock employed was an ethanol suspension of about 7-8wt% YSZ submicron sized particles.
- the suspension was radially injected into the plasma effluent externally of the Progressive Surface 100HETM.
- the torch was rastered across the part at a constant surface speed for a select number of passes until the desired coating thickness was accumulated.
- the topcoat for the APS Densely Vertically Cracked (DVC) coating in Example 2 was produced using a PST 1100 series torch.
- the feedstock employed with the torch was an ethanol suspension of about 7-8wt% YSZ submicron sized particles.
- Plasma spray conditions were operated at 90 grams/minute of feedstock.
- the total current employed ranged from 150-170 Amps.
- the primary torch gas flows was 90 scfh torch gas; 90 scfh argon; and 40 scfh hydrogen gas.
- Each FCT cycle consisted of exposing the coated sample to an elevated temperature of 2075F and holding at such temperature for 50 min followed by cooling the coated sample to 75F for 10 minutes. The average number of FCT cycles completed under such conditions was determined for each of the coatings tested. The coating was considered to fail after 20% of the total coating area was determined to spall from the substrate. A high number of FCT cycles prior to failure is desirable.
- Coated samples were also prepared from the modified composite TBC's of the present invention and various other materials to test for resistance against mechanical erosion.
- Each mechanical erosion test was conducted under controlled conditions that consisted of subjecting the coated samples to angular- shaped, alumina particles having a median size of 50 microns. The particles impinged the coated sample at a particle velocity of 200 ft/sec at 20C room temperature.
- An erosion rate is established for the test sample based on the exposure to a set mass of alumina erosion media. In other words, a mass of eroded coating material per mass of alumina erosion media is determined. A low erosion rate is desirable.
- a non-composite coating was prepared (designated Columnar SPS Baseline) from a feedstock material of 7-8wt% yttria stabilized zirconia (YSZ) in an ethanol-based suspension.
- the material had a submicron size of about 330 nm diameter.
- the material was suspended in the ethanol-based suspension and then thermally sprayed onto a smooth substrate having a surface roughness of about 25-40 ⁇ .
- a coating thickness of about 12 - 15 mil was obtained.
- the resultant coating comprised macro columnar features.
- the column features were generally uniform in width across the surface of the substrate with each other.
- the features were also equivalent in height with each other.
- a regular smooth interface having uniform coating thickness was produced.
- a non-composite coating was prepared (designated APS DVC) from a feedstock material of 7-8 wt% YSZ dry powder.
- the material had a median particle diameter of 22 - 62 ⁇ .
- the material was thermally sprayed by APS onto a smooth substrate having a surface roughness Ra of about 25-40 ⁇ . It was observed that that the APS DVC coating exhibited poor quality and coverage. The coating quality was too poor to produce any substantial coating, and only a maximum thickness of 1 mil was obtained in those regions where it was considered adherent.
- Additional coated non-composite samples were prepared for mechanical erosion testing.
- the erosion rate was determined in units of mg of tested material eroded per gram of alumina particle impinging the coated surface.
- the non-composite samples showed an erosion rate of between about .2-.25 mg/g, as shown by the bar labeled "APS DVC" in Figure 10.
- a composite coating system (designated “Columnar SPS Composite A”) was prepared as shown in Figure 7.
- the undercoat layer was prepared from feedstock of 7-8wt% yttria stabilized zirconia (YSZ).
- the undercoat material had a median particle diameter of about 330 nm.
- the undercoat material was suspended in an ethanol based suspension and then thermally sprayed onto a smooth substrate having a surface roughness Ra of about 25-40 ⁇ .
- the coating thickness of the undercoat was 6 -7 mil.
- the topcoat layer was prepared from a feedstock material of 7-8wt% YSZ.
- the top topcoat material had a median particle diameter of about 2 ⁇ .
- the topcoat material was suspended in a liquid carrier of an ethanol-based suspension and then thermally sprayed onto the substrate.
- the coating thickness of the topcoat was 4-5 mil.
- the thickness of the composite coating was 10 - 12 mil.
- the resultant composite coating system produced is shown in Figure 7.
- the composite contained a porous macro columnar undercoat and a dense macro columnar top coat.
- the undercoat layer maintained thermomechanical compliance of the coating layer on the smooth substrate surface while the tortuous interfacial boundary provided improved mechanical bonding between the first and the second coating layers.
- a composite coating system (designated “Columnar SPS Composite B") was prepared as shown in Figure 8.
- the undercoat layer was prepared from a feedstock of 7-8wt% yttria stabilized zirconia (YSZ).
- the undercoat material had a median particle diameter of about 330 nm.
- the undercoat material was suspended in an ethanol based suspension and then thermally sprayed onto a smooth substrate having a surface roughness Ra of about 25-40 ⁇ .
- the coating thickness of the undercoat was 6 -7 mils.
- the topcoat layer was prepared from a feedstock material of 7-8 wt% YSZ dry powder having an average particle diameter between 22 - 62 ⁇ .
- the topcoat material was thermally sprayed by atmospheric plasma spraying (APS) onto a smooth substrate surface to produce an APS Densely Vertically Cracked (DVC) topcoat.
- APS atmospheric plasma spraying
- DVC Densely Vertically Cracked
- the thickness of the APS DVC topcoat was about 8 mil and the total composite coating thickness was about 14-15 mil.
- the resultant composite coating system is shown in Figure 8.
- the first coating or undercoat layer was more porous and provided thermomechanical compliance.
- the second coating or topcoat layer was denser and provided a barrier to mechanical erosion.
- the inventive composite coatings have the ability to bond and adhere to smooth substrate interfaces (e.g. ⁇ 100 ⁇ Ra), while also retaining thermal conductivity values consistent with thermal spray coatings. Additionally, the inventive TBC's are produced at a lower cost range in comparison to other typical thermal spray processes. Generally speaking, the ability for conventional TBC's to maintain thermomechanical compliance during repetitive thermal shock cycling was possible only at the expense of significantly reduced erosion resistance and other properties at the bulk and/or free surface of the coated sample. Examples 1 and 2 demonstrate that a specifically designed first coating layer having a non-uniform columnar macrostructure and bonded to a smooth substrate roughness enabled a subsequent second coating compatible with the first coating layer to be applied thereto.
- the second coating is selected so as to complement the first coating layer by exhibiting one or more improved properties at the bulk and/or free surface of the resultant composite coating structure.
- the present invention offers TBC composite structures that possess a combination of improved properties (e.g., thermomechanical compliance and erosion/corrosion resistance) previously recognized as mutually exclusive properties due to competing design considerations.
- any suitable top coating can be utilized to provide desired bulk and free surface coating properties as may be desired for particular TBC applications as well as other types of applications.
- the specifically designed undercoat free surface may be modified as needed to ensure adequate bonding of the particular topcoat. For example, some topcoats may require increased tortuosity (i.e., increased non-uniformity in the heights and widths of adjacent peaks and valleys) of the free surfaces of the undercoat for adequate bonding of the topcoat.
- Properties of the first coating layer are selectively tailored by virtue of the macrostructural features shown in Figures la and lb. Of particular significance is the ability of the present invention to maintain adhesion to a smooth substrate and bond strength during thermal cycling, thereby producing materials with superior thermomechanical compliance in comparison to conventional thermal barrier coatings such as a DVC, abradable coating, environmental barrier coating or a densified columnar coating - none of which can typically maintain sustained adhesion and bond strength during thermal cycling.
- thermal barrier coatings such as a DVC, abradable coating, environmental barrier coating or a densified columnar coating - none of which can typically maintain sustained adhesion and bond strength during thermal cycling.
Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP14802526.5A EP3074546B1 (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings |
MX2016006851A MX2016006851A (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings. |
CA2928776A CA2928776C (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings |
BR112016011819-7A BR112016011819B1 (en) | 2013-11-26 | 2014-10-10 | modified thermal barrier composite coating |
PL14802526T PL3074546T3 (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings |
JP2016533585A JP7097668B2 (en) | 2013-11-26 | 2014-10-10 | Modified heat shield composite coating |
CN201480064103.2A CN105765100A (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/090,513 US20150147524A1 (en) | 2013-11-26 | 2013-11-26 | Modified thermal barrier composite coatings |
US14/090,513 | 2013-11-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015080804A1 true WO2015080804A1 (en) | 2015-06-04 |
Family
ID=51947467
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2014/060104 WO2015080804A1 (en) | 2013-11-26 | 2014-10-10 | Modified thermal barrier composite coatings |
Country Status (10)
Country | Link |
---|---|
US (1) | US20150147524A1 (en) |
EP (1) | EP3074546B1 (en) |
JP (1) | JP7097668B2 (en) |
CN (1) | CN105765100A (en) |
BR (1) | BR112016011819B1 (en) |
CA (1) | CA2928776C (en) |
MX (1) | MX2016006851A (en) |
PL (1) | PL3074546T3 (en) |
SG (1) | SG10201804461SA (en) |
WO (1) | WO2015080804A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106116698A (en) * | 2016-06-21 | 2016-11-16 | 上海交通大学 | A kind of low thermal conductance SiCN Y2siO5environment barrier preparation method of composite coating |
EP3438325A1 (en) * | 2017-07-31 | 2019-02-06 | General Electric Company | Improved adhesion of thermal spray coatings over a smooth surface |
EP3995601A1 (en) * | 2020-11-04 | 2022-05-11 | Siemens Energy Global GmbH & Co. KG | Bilayer thermal barrier coatings with an advanced interface |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10745793B2 (en) | 2015-06-04 | 2020-08-18 | Raytheon Technologies Corporation | Ceramic coating deposition |
JP6908973B2 (en) * | 2016-06-08 | 2021-07-28 | 三菱重工業株式会社 | Manufacturing methods for thermal barrier coatings, turbine components, gas turbines, and thermal barrier coatings |
US10947625B2 (en) | 2017-09-08 | 2021-03-16 | Raytheon Technologies Corporation | CMAS-resistant thermal barrier coating and method of making a coating thereof |
US10550462B1 (en) | 2017-09-08 | 2020-02-04 | United Technologies Corporation | Coating with dense columns separated by gaps |
JP7284553B2 (en) * | 2017-09-21 | 2023-05-31 | 日本特殊陶業株式会社 | Substrate with thermal spray coating and method for manufacturing the same |
CN111417740A (en) * | 2017-12-19 | 2020-07-14 | 欧瑞康美科(美国)公司 | Erosion and CMAS resistant coatings for protecting EBC and CMC layers and thermal spray methods |
CA3094335A1 (en) * | 2018-04-09 | 2019-10-17 | Oerlikon Metco (Us) Inc. | Cmas resistant, high strain tolerant and low thermal conductivity thermal barrier coatings and thermal spray coating method |
CN209694856U (en) * | 2018-07-27 | 2019-11-29 | 佛山市顺德区美的电热电器制造有限公司 | Cookware and cooking apparatus |
WO2023223655A1 (en) * | 2022-05-17 | 2023-11-23 | 三菱パワー株式会社 | Shaft sealing device and rotary machine |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008007870A1 (en) * | 2008-02-06 | 2009-08-13 | Forschungszentrum Jülich GmbH | Thermal barrier coating system and process for its preparation |
EP2341166A1 (en) * | 2009-12-29 | 2011-07-06 | Siemens Aktiengesellschaft | Nano and micro structured ceramic thermal barrier coating |
US20130224453A1 (en) * | 2012-02-29 | 2013-08-29 | United Technologies Corporation | Spallation-Resistant Thermal Barrier Coating |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04323358A (en) * | 1991-01-16 | 1992-11-12 | Sumitomo Metal Ind Ltd | Plasma spraying method |
JP2003160852A (en) * | 2001-11-26 | 2003-06-06 | Mitsubishi Heavy Ind Ltd | Thermal insulating coating material, manufacturing method therefor, turbine member and gas turbine |
WO2003087422A1 (en) * | 2002-04-12 | 2003-10-23 | Sulzer Metco Ag | Plasma injection method |
US6764779B1 (en) * | 2003-02-24 | 2004-07-20 | Chromalloy Gas Turbine Corporation | Thermal barrier coating having low thermal conductivity |
CA2460296C (en) * | 2003-05-23 | 2012-02-14 | Sulzer Metco Ag | A hybrid method for the coating of a substrate by a thermal application of the coating |
US7291403B2 (en) * | 2004-02-03 | 2007-11-06 | General Electric Company | Thermal barrier coating system |
JP4388466B2 (en) * | 2004-12-27 | 2009-12-24 | 三菱重工業株式会社 | Gas turbine, thermal barrier coating material, manufacturing method thereof, and turbine member |
CN100427637C (en) * | 2005-09-21 | 2008-10-22 | 武汉理工大学 | Liquid phase plasma spraying process of preparing nanometer zirconia thermal-barrier coating |
US7955708B2 (en) * | 2005-10-07 | 2011-06-07 | Sulzer Metco (Us), Inc. | Optimized high temperature thermal barrier |
US20080145554A1 (en) * | 2006-12-14 | 2008-06-19 | General Electric | Thermal spray powders for wear-resistant coatings, and related methods |
US8586172B2 (en) * | 2008-05-06 | 2013-11-19 | General Electric Company | Protective coating with high adhesion and articles made therewith |
CA2760005A1 (en) * | 2010-12-21 | 2012-06-21 | Sulzer Metco Ag | Method for the manufacture of a thermal barrier coating structure |
US20130260132A1 (en) * | 2012-04-02 | 2013-10-03 | United Technologies Corporation | Hybrid thermal barrier coating |
-
2013
- 2013-11-26 US US14/090,513 patent/US20150147524A1/en not_active Abandoned
-
2014
- 2014-10-10 CN CN201480064103.2A patent/CN105765100A/en active Pending
- 2014-10-10 SG SG10201804461SA patent/SG10201804461SA/en unknown
- 2014-10-10 WO PCT/US2014/060104 patent/WO2015080804A1/en active Application Filing
- 2014-10-10 MX MX2016006851A patent/MX2016006851A/en unknown
- 2014-10-10 BR BR112016011819-7A patent/BR112016011819B1/en active IP Right Grant
- 2014-10-10 JP JP2016533585A patent/JP7097668B2/en active Active
- 2014-10-10 PL PL14802526T patent/PL3074546T3/en unknown
- 2014-10-10 EP EP14802526.5A patent/EP3074546B1/en active Active
- 2014-10-10 CA CA2928776A patent/CA2928776C/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008007870A1 (en) * | 2008-02-06 | 2009-08-13 | Forschungszentrum Jülich GmbH | Thermal barrier coating system and process for its preparation |
US20110244216A1 (en) * | 2008-02-06 | 2011-10-06 | Alexandra Meyer | Thermal barrier coating system and method for the production thereof |
EP2341166A1 (en) * | 2009-12-29 | 2011-07-06 | Siemens Aktiengesellschaft | Nano and micro structured ceramic thermal barrier coating |
US20130224453A1 (en) * | 2012-02-29 | 2013-08-29 | United Technologies Corporation | Spallation-Resistant Thermal Barrier Coating |
Non-Patent Citations (1)
Title |
---|
HOLGER KASSNER ET AL: "Application of Suspension Plasma Spraying (SPS) for Manufacture of Ceramic Coatings", JOURNAL OF THERMAL SPRAY TECHNOLOGY, vol. 17, no. 1, March 2008 (2008-03-01), pages 115 - 123, XP055163277, ISSN: 1059-9630, DOI: 10.1007/s11666-007-9144-2 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106116698A (en) * | 2016-06-21 | 2016-11-16 | 上海交通大学 | A kind of low thermal conductance SiCN Y2siO5environment barrier preparation method of composite coating |
EP3438325A1 (en) * | 2017-07-31 | 2019-02-06 | General Electric Company | Improved adhesion of thermal spray coatings over a smooth surface |
EP3995601A1 (en) * | 2020-11-04 | 2022-05-11 | Siemens Energy Global GmbH & Co. KG | Bilayer thermal barrier coatings with an advanced interface |
WO2022096211A1 (en) * | 2020-11-04 | 2022-05-12 | Siemens Energy Global GmbH & Co. KG | Bilayer thermal barrier coatings with an advanced interface |
Also Published As
Publication number | Publication date |
---|---|
BR112016011819B1 (en) | 2021-02-23 |
CA2928776C (en) | 2022-09-20 |
CA2928776A1 (en) | 2015-06-04 |
EP3074546A1 (en) | 2016-10-05 |
MX2016006851A (en) | 2016-12-15 |
CN105765100A (en) | 2016-07-13 |
JP7097668B2 (en) | 2022-07-08 |
SG10201804461SA (en) | 2018-07-30 |
PL3074546T3 (en) | 2019-11-29 |
JP2016540890A (en) | 2016-12-28 |
EP3074546B1 (en) | 2019-06-19 |
US20150147524A1 (en) | 2015-05-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2928776C (en) | Modified thermal barrier composite coatings | |
EP1295964B1 (en) | Dual microstructure thermal barrier coating | |
US10947625B2 (en) | CMAS-resistant thermal barrier coating and method of making a coating thereof | |
CN109874330B (en) | Method for coating the surface of a solid substrate with a layer containing a ceramic compound and coated substrate obtained | |
US20090252985A1 (en) | Thermal barrier coating system and coating methods for gas turbine engine shroud | |
EP2193217B1 (en) | Imparting functional characteristics to engine portions | |
JP6387005B2 (en) | Thermal barrier coating system and its production and use | |
US20130260132A1 (en) | Hybrid thermal barrier coating | |
EP2305852B1 (en) | Method for the Production of a single layer bond coat. | |
EP2208805A1 (en) | Strain tolerant thermal barrier coating system | |
US9017792B2 (en) | Tri-barrier ceramic coating | |
JP5300851B2 (en) | CERAMIC LAYER COMPOSITE AND METHOD FOR PRODUCING THE CERAMIC LAYER COMPOSITE | |
EP2322686B1 (en) | Thermal spray method for producing vertically segmented thermal barrier coatings | |
US10550462B1 (en) | Coating with dense columns separated by gaps | |
EP2971240B1 (en) | Hybrid thermal barrier coating and process of making the same | |
EP2339051B1 (en) | Article having thermal barrier coating | |
Toma et al. | Performance of suspension sprayed YSZ thermal barrier coatings on Inconel 718 substrates produced by laser powder bed fusion | |
Lokachari et al. | Effect of Microstructure on CMAS Interaction of Axial Suspension and Solution Precursor Plasma Sprayed Thermal Barrier Coatings—YSZ & GZ | |
Musalek et al. | Heterogeneous Thermal Barrier Coatings with Engineered Gradient Interfaces | |
Lu et al. | Microstructural evolution and mechanical properties of vertical-cracked thermal barrier coatings in thermal exposure | |
Lima et al. | A Comparison of Thermal Shock Behavior between APS and Low-Energy VLPPS ZrO2-7% Y2O3 Thermal Barrier Coatings | |
Zhu et al. | A Comparison of Thermal Shock Behavior between APS and Low-Energy VLPPS ZrO2-7% Y2O3 Thermal Barrier Coatings |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 14802526 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2928776 Country of ref document: CA |
|
ENP | Entry into the national phase |
Ref document number: 2016533585 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2016/006851 Country of ref document: MX |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112016011819 Country of ref document: BR |
|
REEP | Request for entry into the european phase |
Ref document number: 2014802526 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014802526 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 112016011819 Country of ref document: BR Kind code of ref document: A2 Effective date: 20160524 |