A method for preparing an ablation-resistant coating for a hydrogen-fueled gas turbine composite blade

Abstract

The application belongs to the field of inorganic nonmetallic materials, and particularly relates to a preparation method of a hydrogen combustion gas turbine composite material blade anti-ablation coating. The anti-ablation coating is coated on a ceramic matrix composite material blade gas flow channel surface, and is composed of an encapsulation layer, a chemical barrier layer, a water and oxygen resistance layer and a heat insulation layer from inside to outside. The anti-ablation coating is prepared by adopting slurry impregnation, plasma spraying and vibration polishing treatment composite technology, and can meet the protection requirements of the ceramic matrix composite material blade under a 1600 DEG C hydrogen combustion environment. The preparation method of the hydrogen combustion gas turbine composite material blade anti-ablation coating has the advantages of convenient construction, excellent aerodynamic characteristics, good hydrogen ablation resistance and CMAS corrosion resistance and long service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of inorganic non-metallic materials, and particularly relates to a preparation method of an ablation-resistant coating for a hydrogen-fueled gas turbine composite blade. BACKGROUND

[0002] Under the background of the "double carbon" emission reduction target, hydrogen as a clean and sustainable energy carrier has attracted widespread attention. The hydrogen-fueled gas turbine, which has the advantages of zero carbon emission and flexible control, will replace the traditional gas turbine and become an inevitable choice for achieving the "double carbon" emission reduction target in the energy field. The hydrogen-fueled gas turbine is a kind of power equipment that uses hydrogen-rich fuel and pure oxygen as oxidant to generate high-temperature and high-pressure water vapor (1750℃) through direct combustion, and then directly enters the turbine to work. Its thermal efficiency can reach more than 70%. However, the high-temperature and high-pressure water vapor with a temperature as high as 1750℃ directly acting on the turbine blade components puts high requirements on the temperature resistance and durability of the turbine components.

[0003] Silicon carbide ceramic matrix composites (SiC-CMCs) have low density (about 1 / 3 of high-temperature alloy), high specific strength, insensitivity to cracks, and resistance to high temperature and chemical corrosion, and are one of the most potential structural materials to replace high-temperature alloys in the future. However, in the service environment of the hydrogen-fueled gas turbine using hydrogen as fuel, a large amount of water vapor and excess oxygen generated by combustion reacts with SiC under high temperature conditions to generate volatile Si(OH)4, which leads to rapid consumption of the matrix material, which is one of the main reasons limiting the application of SiC f / SiC materials. In particular, the SiC f / SiC composite blade components work under the condition of ablation of hydrogen fuel at a temperature of more than 1750℃, and a large amount of water vapor generated during ablation causes water-oxygen coupling corrosion damage, which is the main factor causing premature failure of SiC f / SiC composite blades. It is urgent to develop a protective coating material with high-temperature ablation resistance and water-oxygen corrosion resistance and a preparation method thereof. SUMMARY

[0004] To solve the technical problems in the prior art, the application aims to provide a preparation method of an ablation-resistant coating for a hydrogen-fueled gas turbine composite blade.

[0005] The technical scheme of the application is as follows:

[0006] A preparation method of an ablation-resistant coating for a hydrogen-fueled gas turbine composite blade, wherein the ablation-resistant coating is coated on the SiC fThe SiC composite vane gas flow channel surface is composed of an encapsulation layer, a chemical barrier layer, a water and oxygen resistant layer and a thermal insulation layer from inside to outside, and an anti-ablation coating is prepared by slurry impregnation and plasma spraying composite technology. The specific preparation process includes the following steps.

[0007] Step 1: Pre-treatment of the substrate surface: The non-gas flow channel surface of the SiCf / SiC composite vane is protected by a high-temperature shielding material, the gas flow channel surface of the SiCf / SiC composite vane is cleaned with acetone, and after drying, the gas flow channel surface is textured by high-energy beam, obtaining a gas flow channel surface with a surface roughness not less than Ra3.2 and a reaction layer depth ≤5 μm;

[0008] Step 2: Encapsulation of the substrate: Distilled water, Si powder with a particle size of 1 μm-10 μm, TiC powder with a particle size of 1 μm-10 μm and HfB2 powder with a particle size of 1 μm-10 μm are mixed in a mass ratio of 100:50:10:5 and ball milled for 8-24 hours to prepare a slurry, and the SiCf / SiC composite vane is immersed in the slurry for 10-50 minutes; the SiCf / SiC composite vane after infiltration is placed in a 1400℃-1600℃ protective atmosphere furnace for high temperature sintering treatment, and the SiCf / SiC composite vane after sintering treatment is treated by diamond abrasive belt surface polishing to remove residual sintering residues;

[0009] Step 3: Preparation of the gas flow channel surface coating by plasma spraying technology: the gas flow channel surface of the SiCf / SiC composite vane after step 1 and step 2 is sequentially sprayed with a chemical barrier layer, a water and oxygen resistant layer and a thermal insulation layer, wherein the chemical barrier layer is composed of RESiO4 with a thickness of 100 μm-150 μm; the water and oxygen resistant layer is composed of rare earth monosilicate RE2SiO5 with a thickness of 100 μm-150 μm; the thermal insulation layer is composed of Al2O3, SiO2 and HfO2 with a thickness of 100 μm-150 μm; the substrate surface temperature during spraying is controlled at 600-800℃, and the coating-substrate interface strength is ≥15 MPa;

[0010] Step 4: Vibration polishing treatment: SiC particles are used as abrasive, and vibration polishing technology is used to polish the gas flow channel surface coating, and after polishing, the coating surface finish is not less than Ra1.6 μm;

[0011] Step 5: Stress relief treatment: remove the shielding material from the non-gas flow channel surface, and place the SiCf / SiC composite vane with coating in a protective atmosphere furnace for stress relief treatment at a temperature of 600-1500℃.

[0012] The step 1 high-energy beam texturing treatment technology uses a femtosecond laser or a plasma jet.

[0013] The chemical barrier layer is one of HfSiO4 or ZrSiO4 or their modified products.

[0014] The water- and oxygen-resistant layer is one of Yb2SiO5, Lu2SiO5, and Sc2SiO5, or one of Yb2SiO5 and its modified products.

[0015] The heat insulation layer is composed of Al2O3, SiO2 and cubic HfO2, wherein the molar ratio of the three components is (10-30)%: (10-30)%; (40-80)%.

[0016] The cubic HfO2 structure is modified by adding one of the elements Y, Yb, or Gd.

[0017] The plasma spraying technology is atmospheric plasma spraying or vacuum plasma spraying, with a spraying power of 30-90kW.

[0018] The SiCf / SiC composite blades are prepared using one of the following processes: MI process, PIP process, or CVI process.

[0019] The beneficial effects of this invention are:

[0020] 1) This invention is specifically for SiC f To address the issues of porosity, fiber exposure, and reduced mechanical properties during the forming process of SiC composite blades, this paper proposes an encapsulation material composed of Si, TiC, and HfB2, employing a slurry impregnation process to encapsulate SiC. f The SiC composite material blades are encapsulated using this material, which has advantages such as strong permeability, good wettability with the matrix, and good thermal compatibility, effectively solving the problems of SiC... f The problem of pores and exposed fibers during the forming process of SiC composite blades. By adding TiC and HfB2, hafnium silicate is formed during long-term high-temperature service. It has excellent chemical compatibility and thermal matching with the RESiO4 chemical barrier layer, which can further improve the temperature resistance and high-temperature stability of the encapsulation layer and solve the problems of low melting point (1410℃) and easy volatility of traditional silicon adhesive layers.

[0021] 2) A RESiO4 chemical barrier layer and a RE2SiO5 rare-earth monosilicate environmental barrier layer were sequentially prepared using plasma spraying technology. The RESiO4 layer has a high melting point (~1750℃) and a low coefficient of thermal expansion (3.6~4.0×10⁻⁶). -6The high-temperature oxidation rate of the packaging layer and the SiC substrate can be significantly reduced, and the interface stability of the coating can be improved by the low oxygen diffusion rate and the low oxygen diffusion rate. The RE2SiO5 layer has a very low silica activity and good CMAS corrosion resistance, which can significantly reduce the corrosion effect of the hydrogen atmosphere on the substrate. The cubic structure HfO2 heat insulation layer has a high melting point (~ 2800℃) and low thermal conductivity (≤1.0 W / m·K), which can significantly improve the temperature resistance and heat insulation performance of the coating, and meet the requirements of the composite function of serving at a temperature above 1600℃ and resisting hydrogen atmosphere ablation.

[0022] 3) The high-energy beam, plasma spraying and vibration light decoration composite process can be used to prepare the coating, which can realize the preparation of the complex blade surface anti-hydrogen atmosphere ablation and CMAS corrosion composite function coating, and has the advantages of short process cycle, low cost and strong controllability. The surface roughness of the coating is Ra1.6μm, which can significantly improve the aerodynamic characteristics and CMAS corrosion resistance of the ceramic matrix composite blade surface. DETAILED DESCRIPTION

[0023] The application will be further described in detail below with reference to the examples. It should be understood that the preparation method described in the examples of the application is only used to illustrate the application, and is not a limitation on the application. Simple improvements of the preparation method of the application under the concept of the application also belong to the scope of protection of the application.

[0024] A preparation method of a hydrogen combustion gas turbine composite material blade ablation-resistant coating, the ablation-resistant coating is coated on the SiC f / SiC composite material blade gas flow channel surface, which is composed of a packaging layer, a chemical barrier layer, a water and oxygen resistant layer and a heat insulation layer from inside to outside. The ablation-resistant coating is prepared by slurry impregnation and plasma spraying composite technology. The chemical barrier layer is one of HfSiO4 or ZrSiO4 or a modified product thereof. The water and oxygen resistant layer is one of Yb2SiO5, Lu2SiO5, Sc2SiO5 or one of Yb2SiO5 and a modified product thereof. The heat insulation layer is composed of Al2O3, SiO2 and cubic structure HfO2, and the molar ratio of the three components is (10-30) %:(10-30) %:(40-80) %.

[0025] The specific preparation process includes the following steps:

[0026] Step 1: substrate surface pretreatment: high-temperature resistant shielding is used to protect the non-gas flow channel surface of the SiCf / SiC composite material blade, the SiCf / SiC composite material blade gas flow channel surface is cleaned with acetone, and after drying, high-energy beam is used for texturing treatment of the gas flow channel surface to obtain a gas flow channel surface with a surface roughness not less than Ra3.2 and a reaction layer depth ≤5μm. The high-energy beam texturing treatment technology uses a femtosecond laser or a plasma jet.

[0027] Step 2 matrix encapsulation: distillated water, Si powder with a particle size of 1-10 μm, TiC powder with a particle size of 1-10 μm and HfB2 powder with a particle size of 1-10 μm are mixed in a mass ratio of 100:50:10:5 and ball-milled for 8-24 hours to prepare a slurry, and the SiCf / SiC composite vane is immersed in the slurry for 10-50 minutes for infiltration; the infiltrated SiCf / SiC composite vane is placed in a 1400-1600 °C protective atmosphere furnace for high-temperature sintering treatment, and the sintered SiCf / SiC composite vane is subjected to surface polishing treatment with a diamond abrasive belt to remove residual sintering residues;

[0028] Step 3: a gas flow channel surface coating layer is prepared by plasma spraying technology: the gas flow channel surface of the SiCf / SiC composite vane treated in step 1 and step 2 is successively sprayed with a chemical barrier layer, a water and oxygen resistant layer and a thermal insulation layer, wherein the chemical barrier layer is composed of RESiO4 and has a thickness of 100-150 μm; the water and oxygen resistant layer is composed of rare earth monosilicate RE2SiO5 and has a thickness of 100-150 μm; the thermal insulation layer is composed of Al2O3, SiO2 and HfO2 and has a thickness of 100-150 μm; the substrate surface temperature during the spraying process is controlled at 600-800 °C, and the interface strength between the coating and the substrate is ≥15 MPa; the cubic structure HfO2 is modified by adding one of Y, Yb and Gd elements. The plasma spraying technology is atmospheric plasma spraying or vacuum plasma spraying, and the spraying power is 30-90 kW.

[0029] Step 4: vibration polishing treatment: the gas flow channel surface coating layer is polished by vibration polishing technology using SiC particles as abrasive, and the surface roughness of the coating after polishing is not less than Ra1.6 μm.

[0030] Step 5: stress relief treatment: the shielding material is removed from the non-gas flow channel surface, and the SiCf / SiC composite vane with the coating is placed in a protective atmosphere furnace for stress relief treatment at a temperature of 600-1500 °C.

[0031] The SiCf / SiC composite vane is prepared by one of the MI process, the PIP process or the CVI process.

[0032] Example 1

[0033] A typical hydrogen-fueled gas turbine guide vane component, the matrix material of which is PIP process SiC f / SiC composite material. The surface of the component is ultrasonically cleaned with acetone, and after the surface is dried with compressed air, the component is placed in a resistance furnace for drying treatment.

[0034] Pre-treatment of substrate surface: SiC f / SiC composite vane non-gas flow channel surface protection, using acetone to clean SiC f / SiC composite vane gas flow channel surface, after drying, using femtosecond laser beam to perform roughening treatment on the gas flow channel surface, obtaining a surface roughness Ra3.2μm, a reaction layer depth of 2μm, and the laser beam parameters used are: laser frequency 1.0MHZ, pulse width 10μs, scanning speed 400mm / s.

[0035] Substrate packaging: distill water, Si powder with a particle size of 1μm, TiC powder with a particle size of 1μm, and HfB2 powder with a particle size of 1μm are mixed in a mass ratio of 100:50:10:5 and ball milled for 12 hours to prepare a slurry, and the composite vane is immersed in the slurry for 30 minutes. The infiltrated vane is placed in a 1500℃ protective atmosphere furnace for high temperature sintering treatment, and the sintered vane is subjected to surface polishing treatment using a diamond abrasive belt to remove residual sintering residues.

[0036] Plasma spraying: using plasma spraying technology to spray chemical barrier layer, water and oxygen resistant layer and thermal insulation layer on the SiC f / SiC composite vane gas flow channel surface, wherein the chemical barrier layer is composed of HfSiO4 with a thickness of 125μm; the water and oxygen resistant layer is composed of rare earth monosilicate Yb2SiO5 with a thickness of 125μm; the thermal insulation layer is composed of Al2O3, SiO2 and HfO2 with a thickness of 150μm. The atmospheric plasma spraying parameters used are: power 55kW, argon flow rate 50NLPM, powder feeding speed 10g / min, spraying distance 150mm. The substrate surface temperature is controlled at 700℃ during spraying, and the interfacial strength between the coating and the substrate can reach 19.2MPa;

[0037] Vibratory finishing treatment: using SiC particles as abrasive, the gas flow channel coating is polished using vibratory finishing technology, the abrasive size is 200 mesh, and the main parameters are: frequency 50Hz; total surface finishing time 20min. After foaming, the coating surface finish is Ra1.6μm.

[0038] Stress relief treatment: removing the shielding of the non-gas flow channel, the SiC f / SiC composite vane with coating is placed in a protective atmosphere furnace for stress relief treatment, and the stress relief treatment temperature is 1300℃.

[0039] The typical properties of the ablation-resistant coating of the hydrogen-fueled gas turbine composite vane are as follows:

[0040]

[0041] Example 2

[0042] Typical hydrogen-fueled gas turbine guide vane component, base material is SiC f / SiC composite. The surface of the component is ultrasonically cleaned with acetone, and after the surface is dried with compressed air, it is placed in a resistance furnace for drying treatment.

[0043] Pre-treatment of the surface of the base: the SiC f / SiC composite vane non-gas flow face is protected, and the SiC f / SiC composite vane gas flow face is treated with plasma jet after drying, to obtain a surface roughness Ra3.2 μm and a reaction layer depth of 5 μm. The plasma jet parameters used are: plasma power 90 kW, scanning speed 400 mm / s.

[0044] Base encapsulation: distilled water, Si powder with a particle size of 5 μm, TiC powder with a particle size of 1 μm, and HfB2 powder with a particle size of 1 μm are mixed in a mass ratio of 100:50:10:5 and ball milled for 12 hours to prepare a slurry, and the composite vane is immersed in the slurry for 50 minutes. The infiltrated vane is placed in a 1500°C protective atmosphere furnace for high-temperature sintering treatment, and the sintered vane is surface polished with a diamond abrasive belt to remove residual sintering residues.

[0045] Plasma spraying: a chemical barrier layer, a water and oxygen resistant layer, and a thermal insulation layer are successively sprayed on the SiC f / SiC composite vane gas flow face using plasma spraying technology, wherein the chemical barrier layer is composed of ZrSiO4 with a thickness of 100 μm; the water and oxygen resistant layer is composed of rare earth monosilicate Lu2SiO5 with a thickness of 100 μm; and the thermal insulation layer is composed of Al2O3, SiO2, and HfO2 with a thickness of 100 μm. The atmospheric plasma spraying parameters used are: power 65 kW, argon flow rate 55 NLPM, powder feeding speed 10 g / min, and spraying distance 150 mm. The surface temperature of the base during spraying is controlled at 800°C, and the interfacial strength of the coating and the base can reach 20.6 MPa.

[0046] Vibratory finishing treatment: the gas flow face coating is polished using vibratory finishing technology with SiC particles as the abrasive, with an abrasive size of 200 mesh and main parameters of: frequency 50 Hz; and total surface finishing time 20 min. The surface finish of the coating after foaming is Ra1.6 μm.

[0047] Destress treatment: removing the mask of non-gas flow channel surface, coating SiC f / SiC composite blade is placed in a protective atmosphere furnace for destress treatment, and the destress treatment temperature is 1300℃.

[0048] The typical performance of the obtained hydrogen combustion gas turbine composite blade anti-ablation coating is as follows:

[0049]

Claims

1. A method for preparing an ablation resistant coating for a hydrogen-fueled gas turbine composite blade, the method comprising: The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC f The anti-ablation coating is coated on SiC <000000 Step 1: Surface pretreatment of the substrate: The non-gas flow channel surface of the SiCf / SiC composite blade is protected by a high-temperature-resistant shield, the gas flow channel surface of the SiCf / SiC composite blade is cleaned with acetone, and after drying, the gas flow channel surface is textured by high-energy beam, obtaining a gas flow channel surface with a surface roughness not less than Ra3.2 and a reaction layer depth ≤5 μm; Step 2: Substrate packaging: Distilled water, Si powder with a particle size of 1 μm~10 μm, TiC powder with a particle size of 1 μm~10 μm, and HfB2 powder with a particle size of 1 μm~10 μm are mixed in a mass ratio of 100:50:10:5 and ball milled for 8~24 hours to prepare a slurry, and the SiCf / SiC composite blade is immersed in the slurry for 10~50 minutes; the SiCf / SiC composite blade after infiltration is placed in a 1400℃~1600℃ protective atmosphere furnace for high-temperature sintering treatment, and the SiCf / SiC composite blade after sintering treatment is surface polished by diamond abrasive belt to remove residual sintering residues; Step 3: Preparation of gas flow channel coating by plasma spraying technology: The gas flow channel surface of the SiCf / SiC composite blade treated in steps 1 and 2 is sequentially sprayed with a chemical barrier layer, a water and oxygen resistant layer, and a thermal insulation layer, wherein the chemical barrier layer is composed of RESiO4 with a thickness of 100 μm~150 μm; the water and oxygen resistant layer is composed of rare earth monosilicate RE2SiO5 with a thickness of 100 μm~150 μm; the thermal insulation layer is composed of Al2O3, SiO2, and HfO2 with a thickness of 100 μm~150 μm; the substrate surface temperature during spraying is controlled at 600~800℃, and the interfacial strength between the coating and the substrate is ≥15 MPa; the HfO2 is modified by adding one of Y, Yb, and Gd elements; Step 4: Vibration polishing treatment: SiC particles are used as abrasive, and vibration polishing technology is used to polish the gas flow channel coating, and the surface finish of the coating after polishing is not less than Ra1.6 μm; Step 5: Stress relief treatment: Remove the shield from the non-gas flow channel, and place the SiCf / SiC composite blade with coating in a protective atmosphere furnace for stress relief treatment at a temperature of 600~1500℃.

2. The method of claim 1, wherein the method further comprises: Step 1: High-energy beam texturing technology, using femtosecond laser or plasma jet.

3. The method of claim 1, wherein the method further comprises: The water and oxygen resistant layer is one of Yb2SiO5, Lu2SiO5, Sc2SiO5, or a modified product of Yb2SiO5.

4. The method of claim 1, wherein the method further comprises: The thermal insulation layer is composed of Al2O3, SiO2, and cubic HfO2, and the molar ratio of the three components is (10~30)%:(10~30)%:(40~80)%.

5. The method of claim 1, wherein the method further comprises: The plasma spraying technology is atmospheric plasma spraying or vacuum plasma spraying with a spraying power of 30~90 kW.

6. The method of claim 1, wherein the method further comprises: The SiCf / SiC composite blade is prepared by one of the MI process, PIP process, or CVI process.

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