Alloy powder material, its preparation method and application in water-oxygen corrosion resistant bonding layer of thermal barrier coating

Abstract

This invention relates to an alloy powder material, its preparation method, and its application in a water- and oxygen-corrosion-resistant adhesive layer for thermal barrier coatings, belonging to the technical field of high-temperature coating materials. This invention employs a mechanical alloying process to prepare an alloy powder material for preparing a water- and oxygen-corrosion-resistant adhesive layer for thermal barrier coatings; the process is simple and convenient. The alloy powder material is composed of Yb, Ni, Cr, Al, and Y, resulting in a powder with small particle size, uniform particle distribution, and strong adhesion. Using the alloy powder material of this invention, an adhesive layer for thermal barrier coatings is prepared. In a high-temperature steam environment above 1200℃, the adhesive layer undergoes an in-situ reaction at the ceramic layer interface to generate Yb3Al5O. 12 This slows down the oxidation rate, resists the extreme environment of mixed hydrogen combustion (>1200℃, high partial pressure H2O / O2), improves the water and oxygen corrosion resistance of the thermal barrier coating alloy bonding layer, provides support for extending the service life of the thermal barrier coating, and provides new raw materials for the preparation of thermal barrier coatings.

Description

Technical Field

[0001] This invention relates to the field of high-temperature coating materials technology, and in particular to an alloy powder material, its preparation method, and its application in a water and oxygen corrosion resistant adhesive layer of a thermal barrier coating. Background Technology

[0002] The efficient utilization of green hydrogen energy is becoming a focus of social attention. Green hydrogen energy is closely linked to renewable energy, and its widespread application will strongly promote the dual-carbon transformation process. In the aviation sector, the application of hydrogen energy heralds a major transformation of the industrial chain. Compared with traditional fossil fuels, hydrogen energy significantly reduces carbon dioxide emissions throughout its entire life cycle. To address pollution emissions, noise, and energy conversion efficiency issues in the aviation sector, the industry urgently needs continuous and disruptive technological innovation to overcome key technologies for low-carbon development and achieve a transition to low-carbon energy. Hydrogen fuel cell aircraft engines are a key focus of global aviation research, with development trends pointing towards higher thrust-to-weight ratios, higher bypass ratios, and higher thermal efficiency. With the continuous increase in turbine inlet temperature and the challenges of future hydrogen fuel applications, higher requirements are being placed on the protection of hot-end engine components.

[0003] Thermal barrier coatings play a crucial role in protecting hot-end components of aero-engines and gas turbines. The use of metal-ceramic composite materials can effectively improve the thrust-to-weight ratio and turbine inlet temperature of aero-engines. This coating not only improves engine fuel efficiency and extends service life but also effectively prevents premature hot corrosion of the high-temperature alloy substrate. The binder layer, as the underlayer of the thermal barrier coating, can be prepared using various techniques, including atmospheric plasma spraying (APS) and plasma-sprayed physical vapor deposition (PS-PVD). Metal binder materials readily undergo thermochemical reactions with water vapor at high temperatures. Simultaneously, the thermally grown oxide (TGO) layer formed at the ceramic / metal interface under high temperatures is relatively porous. TGO oxidizes faster in humid air than in dry air, resulting in a thicker TGO layer. Furthermore, when grown in dry air, a uniform α-Al₂O₃ is formed. Humid air conditions prolong the presence of the γ, δ, and θ phases of the oxide. The temporary stability of these phases promotes the growth of unwanted oxides, forming spinels, which in turn promote crack nucleation and propagation.

[0004] Ytterbium aluminum garnet (Yb3Al5O) 12 YbAG (YbAG for short) has attracted attention in recent years as a potential thermal barrier coating (TBC) or environmental barrier coating (EBC) material for hot-end components of gas turbines. This material possesses several excellent properties, including resistance to water vapor corrosion, high compressive strength, low permeability, and low thermal conductivity (coefficient of thermal expansion approximately 8 × 10⁻⁶). -6 YbAG exhibits high temperature phase stability (at / ℃). However, there are currently no reports of its application in the binder layer of thermal barrier coatings. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an alloy powder material with resistance to water and oxygen corrosion, its preparation method, and its application in the water and oxygen corrosion resistant adhesive layer of thermal barrier coatings.

[0006] This invention introduces Yb into the binder layer to prepare YbNiCrAlY alloy powder, which is then applied to the binder layer of a thermal barrier coating. In a high-temperature water vapor environment, Yb and Al elements are preferentially and selectively oxidized. A composition design with a Yb:Al ratio of 3:5 induces the formation of Yb3Al5O3 alloy powder. 12 Due to its topological structure, YbAG exhibits a unique molecular interface passivation effect, where O atoms in H2O molecules are strongly attracted and preferentially "anchored" to the highly positively charged Yb atoms on the YbAG surface. 3+ At the cation site. In the anchored H₂O molecule, the H atom, due to its electron cloud bias towards the O atom, interacts with the neighboring O atom on the YbAG surface. 2- The interaction forces at the anion sites are extremely weak, making it impossible to effectively form stable two-point contacts (i.e., "bridge adsorption"). This asymmetric adsorption mode leads to a significant extension and distortion of the dissociation path of H2O molecules on the YbAG surface. The in-situ generation of YbAG in the binder layer significantly delays the catalytic erosion process of the thermally grown oxide (TGO) layer at the binder / ceramic layer interface by water molecules; it promotes the formation of a thinner, denser, and more adhesive TGO layer dominated by protective α-Al2O3, effectively blocking the formation and excessive growth of harmful spinel phases. This invention provides a new raw material option for the development of hydrogen-mixed combustion turbine engines and has high commercial value.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an alloy powder material, which is prepared by mechanical alloying of elemental metal powders of Yb, Ni, Cr, Al and Y, wherein the atomic ratio of Yb, Ni, Cr, Al and Y is (12~24):(50~70):(16~24):(5~10):0.5.

[0008] The alloy powder material of this invention is an alloy of Yb, Ni, Cr, Al, and Y. Introducing Yb into the alloy powder material improves the resistance to water and oxygen corrosion in the binder layer of a thermal barrier coating prepared from this alloy material. In the binder layer prepared using the YbNiCrAlY alloy material of this invention, Yb and Al elements are preferentially and selectively oxidized in a high-temperature water vapor environment, generating Yb3Al5O3 with specific oxidation properties. 12The topological structure and in-situ generation of YbAG significantly slowed down the catalytic erosion process of TGO at the interface of the adhesive layer / ceramic layer by water molecules; it promoted the formation of a thinner, denser, and more adhesive TGO layer mainly composed of protective α-Al2O3, which effectively blocked the formation and excessive growth of harmful spinel phases, thereby improving the water and oxygen corrosion resistance of the adhesive layer.

[0009] In a preferred embodiment of the alloy powder material of the present invention, the particle size of the alloy powder material is 45~150μm.

[0010] Secondly, the present invention provides a method for preparing the above-mentioned alloy powder material, comprising the following steps: S1. Mix the metallic elements Yb, Ni, Cr, Al and Y in an atomic ratio of (12~24):(50~70):(16~24):(5~10):0.5 to obtain a mixed powder; S2. Place the mixed powder obtained in step S1 and the grinding balls in a reaction vessel, introduce a protective gas, and ball mill thoroughly. After sieving, the resulting powder is the alloy powder material.

[0011] In a preferred embodiment of the preparation method described in this invention, in step S2, the reaction vessel is a polytetrafluoroethylene ball mill jar.

[0012] In a preferred embodiment of the preparation method of the present invention, in step S2, the mass ratio of the mixed powder to the grinding ball is 1:14~18.

[0013] In a preferred embodiment of the preparation method described in this invention, in step S2, the grinding ball is a zirconia ball mill.

[0014] In a preferred embodiment of the preparation method of the present invention, in step S2, the ball milling speed is 300~500 r / min and the ball milling time is 70~90 h.

[0015] In a preferred embodiment of the preparation method of the present invention, the protective gas in step S2 is nitrogen.

[0016] Thirdly, the present invention provides the application of the above-mentioned alloy powder material in the preparation of thermal barrier coatings.

[0017] Fourthly, the present invention provides the application of the above-mentioned alloy powder material in the preparation of the adhesive layer of a thermal barrier coating.

[0018] The alloy powder material of the present invention is instantaneously heated, accelerated and partially ionized in a plasma at a temperature of 10,000 degrees Celsius by directional plasma fusion deposition, forming a high-speed directional particle stream. The particles impact the activated matrix surface with extremely high kinetic energy, resulting in instantaneous metallurgical bonding and thermal densification, forming a bonding layer.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention employs a precise mechanical alloying process to prepare alloy powder materials for the water and oxygen corrosion resistant bonding layer of thermal barrier coatings. The process is simple and convenient to operate. The alloy powder material is composed of Yb, Ni, Cr, Al, and Y, and the resulting powder has the characteristics of small particle size, uniform particle distribution, and strong adhesion. Using the alloy powder material of this invention to prepare the bonding layer of the thermal barrier coating, the bonding layer undergoes an in-situ reaction at the ceramic layer interface in a high-temperature steam environment above 1200℃ to generate Yb3Al5O. 12 YbAG adsorbs water molecules at their apex sites, while only O in gaseous H2O(g) adsorbs metal ions. H has a weak attraction to oxides and cannot directly form bridging sites, resulting in a longer total adsorption-dissociation time. It has a high dissociation energy barrier for water and low reactivity with water, which slows down the oxidation rate. It can withstand extreme environments of mixed hydrogen combustion (>1200℃, high partial pressure H2O / O2), improves the water and oxygen corrosion resistance of the thermal barrier coating alloy bonding layer, provides support for extending the life of thermal barrier coatings, and provides a new raw material for the preparation of thermal barrier coatings. Attached Figure Description

[0020] Figure 1 This is a SEM image of the alloy powder material in Example 1 of the present invention; Figure 2 This is an appearance view of a high-temperature alloy sample after a binder layer has been deposited using alloy powder material from Example 1 of this invention. Figure 3 This is a picture of the appearance of a high-temperature alloy sample after the alloy powder material of Example 1 of the present invention has been deposited with a bonding layer and subjected to water-oxygen corrosion at 1100°C for 200 hours. Figure 4 This is an image of the appearance of a high-temperature alloy sample after the alloy powder material of Example 1 deposits a bonding layer, after 100 cycles of water-oxygen corrosion at 1100°C. Figure 5 The TGO thickness-time curves of the bonding layer prepared by the alloy powder material of Example 3 and Comparative Example 1 of the present invention in a water-oxygen corrosion environment at 1100℃. Detailed Implementation

[0021] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0022] Unless otherwise specified, all other materials and reagents used in the examples are commercially available.

[0023] Example 1 An alloy powder material is prepared by mechanical alloying of elemental metal powders of Yb, Ni, Cr, Al and Y, wherein the atomic ratio of Yb, Ni, Cr, Al and Y is 14:57.5:20:8:0.5.

[0024] The preparation method of alloy powder materials includes the following steps: S1. Mix the elemental metal powders of Yb, Ni, Cr, Al and Y in an atomic ratio of 14:57.5:20:8:0.5 to obtain a mixed powder with a total mass of 300g. S2. Place the mixed powder obtained in step S1 and zirconia grinding balls in a polytetrafluoroethylene ball milling jar, introduce nitrogen as a protective gas to isolate it from air and prevent oxidation, and ball mill at 300 r / min for 90 h. After ball milling, separate the powder by passing it through a 250 mesh sieve to obtain an alloy powder material with a particle size of 45~150 μm; the mass ratio of the mixed powder to the zirconia grinding balls is 1:14. The alloy powder material is stored in a vacuum storage container for later use.

[0025] Example 2 An alloy powder material is prepared by mechanical alloying of elemental metal powders of Yb, Ni, Cr, Al and Y, wherein the atomic ratio of Yb, Ni, Cr, Al and Y is 16:58.5:18:7:0.5.

[0026] The preparation method of alloy powder materials includes the following steps: S1. Mix the metallic elemental powders of Yb, Ni, Cr, Al and Y in an atomic ratio of Yb:58.5:18:7:0.5 to obtain a mixed powder with a total mass of 300g. S2. Place the mixed powder obtained in step S1 and the zirconia grinding balls into a polytetrafluoroethylene ball milling jar, introduce nitrogen as a protective gas to isolate air and avoid oxidation, and ball mill at 400 r / min for 80 h. After ball milling, separate the powder by passing it through a 250 mesh sieve to obtain an alloy powder material with a particle size of 45~150 μm; the mass ratio of the mixed powder to the zirconia grinding balls is 1:16.

[0027] Example 3 An alloy powder material is prepared by mechanical alloying of elemental metal powders of Yb, Ni, Cr, Al and Y, wherein the atomic ratio of Yb, Ni, Cr, Al and Y is 18:59.5:16:6:0.5.

[0028] The preparation method of alloy powder materials includes the following steps: S1. Mix the elemental metal powders of Yb, Ni, Cr, Al and Y in an atomic ratio of 18:59.5:16:6:0.5 to obtain a mixed powder with a total mass of 300g. S2. Place the mixed powder obtained in step S1 and the zirconia grinding balls into a polytetrafluoroethylene ball milling jar, introduce nitrogen as a protective gas to isolate air and avoid oxidation, and ball mill at 500 r / min for 70 h. After ball milling, separate the powder by passing it through a 250 mesh sieve to obtain an alloy powder material with a particle size of 45~150 μm; the mass ratio of the mixed powder to the zirconia grinding balls is 1:18.

[0029] Example 4 An alloy powder material is disclosed. The difference between this embodiment and Example 1 is only in the atomic ratio of Yb, Ni, Cr, Al and Y. In this embodiment, the atomic ratio of Yb, Ni, Cr, Al and Y in Example 1 is adjusted from 14:57.5:20:8:0.5 to 12:50:16:5:0.5, resulting in an alloy powder material with a particle size of 45~150μm.

[0030] Example 5 An alloy powder material is disclosed. The difference between this embodiment and Example 1 is only in the atomic ratio of Yb, Ni, Cr, Al and Y. In this embodiment, the atomic ratio of Yb, Ni, Cr, Al and Y in Example 1 is adjusted from 14:57.5:20:8:0.5 to 24:70:24:10:0.5, resulting in an alloy powder material with a particle size of 45~150μm.

[0031] Comparative Example 1 This invention provides a comparative example of an alloy powder material. The alloy powder material in this comparative example is NiCrAlCoY. The only difference between this comparative example and Example 1 is the composition of the metallic elements in the alloy powder material. In this comparative example, the metallic elements Yb, Ni, Cr, Al and Y in the alloy powder material of Example 1 are replaced with Co, Ni, Cr, Al and Y. The preparation method is the same as in Example 1.

[0032] Co is converted to Co2O3 in a high-temperature steam environment, and Yb is converted to Yb3Al5O in a high-temperature steam environment. 12 (YbAG) has stronger resistance to water vapor corrosion than Co2O3.

[0033] Test Example 1 The morphology of the alloy powder materials in the examples was analyzed by scanning electron microscopy (SEM).

[0034] The alloy powder materials in Examples 1-5 have good particle dispersion, with particle sizes ranging from 45 to 150 μm and relatively uniform particle size, with an average particle size of about 50 μm.

[0035] SEM image of alloy powder material in Example 1 is shown below. Figure 1 As shown.

[0036] Test Example 2 The alloy powder materials from Examples 1-5 and Comparative Example 1 were processed into a binder coating for a thermal barrier coating, with a nickel-based superalloy as the substrate material. The alloy powder materials were deposited onto a pretreated nickel-based superalloy substrate using low-pressure plasma spraying. The deposition parameters were: current 720 A, argon flow rate 60 L / min, hydrogen flow rate 8 L / min, and spraying distance 290 mm, resulting in a binder coating with a thickness of approximately 180 μm. The superalloy samples after the binder coating was deposited underwent high-temperature water-oxygen corrosion resistance testing. The appearance of the superalloy sample after the binder coating was deposited using the alloy powder material from Example 1 is shown in the figure. Figure 2 As shown.

[0037] The test employed a high-temperature tubular furnace as the core equipment, capable of operating at a maximum temperature of 1600℃, and equipped with high-temperature thermocouples for precise temperature control. During the test, saturated water vapor and compressed air were introduced into the furnace chamber at a flow rate of 15–18 L / min to simulate the high-temperature water-oxygen environment generated by hydrogen combustion. The temperature of the furnace chamber's insulation zone was precisely stabilized at 1100℃ through thermocouple calibration, and temperature cycling was performed at a rate of 10℃ / min to simulate the thermal cycling process under actual operating conditions. This method can effectively evaluate the water-oxygen corrosion resistance and thermal cycling stability of the thermal barrier coating's adhesive layer in a high-temperature water-oxygen environment.

[0038] Water and oxygen corrosion resistance: The sample was placed in a tube furnace, heated to 1100℃ and steam was introduced. After the temperature reached 1100℃, the timer was started. The sample was taken out after 25h, 50h, 100h, 150h and 200h respectively, cooled in air and the surface morphology of the sample was observed.

[0039] The results showed that the binder layer prepared from the alloy powder material in the example exhibited a smooth surface without peeling after 200 hours of water-oxygen corrosion at 1100℃, and the oxide layer on the surface was uniform and dense, demonstrating good resistance to water-oxygen corrosion. The appearance of the high-temperature alloy sample after depositing the binder layer using the alloy powder material of Example 1 and undergoing 200 hours of water-oxygen corrosion at 1100℃ is shown in the image below. Figure 3 As shown.

[0040] After water-oxygen corrosion at 1100℃ for 200 hours, the bonding layer prepared by the alloy powder material in Comparative Example 1 showed obvious granular, island-like or nodular morphology of the outer oxide layer, which caused the overall surface to change from the original relatively flat to a rough and undulating structure.

[0041] Thermal cycling stability: The sample was placed in a tube furnace, heated to 1100°C and steam was introduced. Timing was started after the temperature reached 1100°C. After 1 hour, the sample was removed, cooled in air for 10 minutes, and then placed back into the tube furnace at 1100°C. This process was repeated 100 times.

[0042] The results showed that the binder layer prepared from the alloy powder material in the example exhibited a smooth surface without peeling after 100 cycles (100 h) of water-oxygen corrosion at 1100℃, with a uniform and dense oxide layer and good thermal cycling stability. The appearance of the high-temperature alloy sample after 100 cycles of water-oxygen corrosion at 1100℃ following the deposition of the binder layer using the alloy powder material of Example 1 is shown in the image below. Figure 4 As shown.

[0043] After 100 cycles of water-oxygen corrosion at 1100℃, the bonding layer prepared from the alloy powder material in Comparative Example 1 showed accumulation of granular and nodular mixed oxides and local peeling of the oxide layer on its surface.

[0044] Oxidation rate: The thickness of thermally grown oxide (TGO) of the sample during the water-oxygen corrosion process at 1100℃ was measured, and the thickness changes of the two samples were compared to determine the rate of oxidation.

[0045] The TGO thickness of the bonding layer prepared by the alloy powder materials in Examples 1-5 after water-oxygen corrosion at 1100℃ for 300h was 7.05~7.82μm.

[0046] The TGO thickness-time curves of the bonding layers prepared from the alloy powder materials in Example 3 and Comparative Example 1 in a 1100℃ water-oxygen corrosion environment are shown below. Figure 5 As shown, the results indicate that the TGO thickness of the bonding layer prepared by the alloy powder material in Example 3 after water-oxygen corrosion at 1100℃ for 300h is approximately 7.25μm, while the TGO thickness of the bonding layer prepared by the alloy powder material in Comparative Example 1 after water-oxygen corrosion at 1100℃ for 300h is approximately 8.44μm. The oxidation rate corresponding to Example 3 is approximately 14% lower than that corresponding to Comparative Example 1.

[0047] In summary, the thermal barrier coating prepared by the alloy powder material of this invention has good resistance to water and oxygen corrosion, thermal cycling stability, and a lower oxidation rate.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An alloy powder material, characterized in that, It is prepared by mechanical alloying of metallic elemental powders of Yb, Ni, Cr, Al and Y, wherein the atomic ratio of Yb, Ni, Cr, Al and Y is (12~24):(50~70):(16~24):(5~10):0.

5.

2. The alloy powder material as described in claim 1, characterized in that, The particle size of the alloy powder material is 45~150μm.

3. The method for preparing the alloy powder material according to claim 1 or 2, characterized in that, Includes the following steps: S1. Mix the metallic elements Yb, Ni, Cr, Al and Y in an atomic ratio of (12~24):(50~70):(16~24):(5~10):0.5 to obtain a mixed powder; S2. Place the mixed powder obtained in step S1 and the grinding balls in a reaction vessel, introduce a protective gas to isolate oxygen, and ball mill thoroughly. After sieving, the resulting powder is the alloy powder material.

4. The preparation method according to claim 3, characterized in that, In step S2, the reaction vessel is a polytetrafluoroethylene ball mill jar.

5. The preparation method according to claim 3, characterized in that, In step S2, the mass ratio of the mixed powder to the grinding ball is 1:14~18.

6. The preparation method according to claim 3, characterized in that, In step S2, the grinding ball is a zirconia ball mill.

7. The preparation method according to claim 3, characterized in that, In step S2, the rotational speed of the ball mill is 300~500 r / min; And / or, in step S2, the ball milling time is 70~90h.

8. The preparation method according to claim 3, characterized in that, In step S2, the protective gas is nitrogen.

9. The application of the alloy powder material according to claim 1 or 2 in the preparation of thermal barrier coatings.

10. The use of the alloy powder material according to claim 1 or 2 in the preparation of the adhesive layer of a thermal barrier coating.

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