Novel bonding layer material for high-temperature-resistant thermal environment barrier coating as well as preparation method and application of novel bonding layer material

Abstract

The invention provides a novel bonding layer material for a high-temperature-resistant thermal environment barrier coating as well as a preparation method and application of the novel bonding layer material, and relates to the technical field of high-temperature thermal protection coating materials. The bonding layer is made of Si-MSi2, and M is selected from one or more of Y, Mo, Hf, Nb, Ta, Re and Ti. According to the novel bonding layer material for the high-temperature-resistant thermal environment barrier coating, MSi2 is introduced, so that an oxide generated at a high temperature can react with SiO2 in TGO to form M2Si2O7, the volume effect can be relieved, the interlayer thermal expansion gradient can be bridged due to the low thermal expansion coefficient of MSi2, the interface compatibility is remarkably improved, stress accumulation in the thermal cycle process is inhibited, and the thermal performance of the coating is improved. And meanwhile, the bonding layer material can also improve the high-temperature resistance of the coating, so that the coating is suitable for a harsh high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature thermal protective coating materials, and in particular to a novel bonding layer material for a high-temperature thermal environment resistant barrier coating, and a preparation method and application thereof. Background Art

[0002] As aircraft engines develop towards a higher thrust-to-weight ratio, the service temperature of hot end components has exceeded the 1350°C limit. Traditional nickel-based high-temperature alloys are gradually being replaced by silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC f / SiC-CMCs) instead. This material has become an ideal substrate for the hot end components of the new generation of engines due to its low density, excellent high temperature strength and oxidation resistance. However, SiC f The interface mismatch between SiC-CMCs and thermal environment barrier coatings (TEBCs) seriously restricts their engineering applications: on the one hand, the difference in thermal expansion coefficients between the substrate and the coating leads to interfacial stress accumulation during thermal cycling; on the other hand, excessive diffusion of silicon elements in high temperature environments easily forms a brittle aluminosilicate phase, causing the coating to peel off and fail.

[0003] Existing bonding layer technologies (such as MCrAlY alloy or Al-Si coating) still have the following significant limitations in extreme thermomechanical coupling environments: (1) Traditional metal bonding layers fail due to oxidation at temperatures ≥1200°C, and the thermal expansion coefficient differs significantly from that of ceramic coatings (ΔCTE ≥3×10 -6 / K), which can easily lead to the initiation of interface cracks; (2) Although a single silicon-based bonding layer can alleviate the CTE (coefficient of thermal expansion) mismatch, active silicon can easily react with the substrate at high temperatures (>1300℃) to form a low-melting-point SiO2 transition layer, accelerating interface degradation; (3) Although complex multi-component bonding layers (such as Si-HfO2-Y2O3 system) can improve thermal stability, their preparation process is cumbersome and the risk of component segregation is high, making it difficult to meet the stringent requirements of aviation components for coating reliability.

[0004] In addition, the most widely used silicon bonding layer has a specific pain point: SiO2 thermally grown oxide (TGO) is easily formed during high-temperature oxidation. Since the conversion of Si→SiO2 is accompanied by a volume expansion of about 2.2 times, a growth stress of up to 1.8~2.3GPa is generated at the interface, which can easily lead to coating warping and interface peeling. Secondly, SiO2 undergoes a reversible phase transition between β-cristobalite (high-temperature phase) and α-cristobalite (low-temperature phase) during high-temperature service. When cooled to 220°C, the β→α phase transition is accompanied by a 4.9% volume shrinkage, while the α→β phase transition causes volume expansion when heated. This cyclic strain is observed in the Si bonding layer (CTE=4.5×10 -6 / K~5.5×10 -6 / K) for SiO2 layer (CTE = 10.3 × 10 -6 / K), a tensile strain exceeding 1.2% will accumulate inside the SiO2 layer, and a through-crack will form after 50 thermal cycles.

[0005] Therefore, there is an urgent need to develop a new bonding layer material to regulate the interface structure and maintain the long-term and stable operation of the coating under extreme working conditions of high temperature (>1300℃). Summary of the Invention

[0006] In view of this, the present invention proposes a new type of bonding layer material for high temperature resistant thermal environment barrier coating and its preparation method and application. Through the innovation of the component of the bonding layer material and the regulation of the interface structure, the bonding layer material is used in the SiC f A composite interface layer with gradient thermal matching, high-temperature chemical stability and oxygen barrier functions is constructed between the SiC-CMCs substrate and the rare earth aluminate coating.

[0007] The technical solution of the present invention is achieved as follows:

[0008] In the first aspect, the present invention provides a novel bonding layer material for a high-temperature thermal environment barrier coating, wherein the bonding layer material is Si-MSi2, wherein the M is selected from one or more of Y, Mo, Hf, Nb, Ta, Re, and Ti.

[0009] In one or some possible embodiments, based on the mass percentage of the bonding layer material, the amount of MSi2 is 20-50 wt %, and the amount of Si is 50-80 wt %.

[0010] By adopting the above technical solution, the thermal expansion coefficient of the mixture in the bonding layer can be made equal to that of SiC f / SiC-CMCs substrate close to ensure that there is no thermal mismatch.

[0011] In a second aspect, the present invention provides a method for preparing the above-mentioned novel bonding layer material for high-temperature thermal environment barrier coating, comprising the following steps:

[0012] After drying Si powder and MSi2 powder respectively, they are mixed according to the mass percentage, ball milled, and then spray granulated to obtain Si-MSi2 bonding layer material with a particle size of 32 to 125 μm.

[0013] In one or some possible embodiments, the present invention relates to an application of the novel bonding layer material for high-temperature resistant thermal environment barrier coating in a thermal environment barrier coating.

[0014] In a third aspect, the present invention provides a novel high-temperature resistant thermal environment barrier coating, comprising a substrate, and an adhesive layer, an environmental barrier coating, and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0015] The substrate is SiCf / SiC-CMCs substrate;

[0016] The bonding layer includes the above-mentioned novel bonding layer material for high-temperature thermal environment barrier coating.

[0017] In one or some possible embodiments, the thickness of the bonding layer is 50-100 μm.

[0018] In one or some possible embodiments, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and / or a Yb2SiO5 environmental barrier coating, and the thickness of any of the environmental barrier coatings is 50 to 100 μm.

[0019] In one or some possible embodiments, the surface thermal barrier coating is selected from Yb3Al5O with a thickness of 50 to 100 μm. 12 Surface thermal barrier coating.

[0020] By adopting this technical solution, the total thickness of the thermal barrier coating is controlled between 300-350μm, balancing the thermal protection capability and structural stability of the thermal barrier coating. A coating that is too thick can easily lead to thermal stress concentration, reduced bonding strength, and process instability. A coating that is too thin cannot provide effective thermal isolation and environmental protection, and is prone to rapid failure under high-temperature service conditions.

[0021] In a fourth aspect, the present invention relates to a method for preparing the above-mentioned novel high-temperature thermal environment barrier coating, comprising the following steps:

[0022] S1. Pre-treating the substrate;

[0023] S2, depositing a bonding layer on the surface of the substrate;

[0024] S3, depositing an environmental barrier coating on the surface of the bonding layer;

[0025] S4. Depositing a surface thermal barrier coating on the surface of the environmental barrier coating to obtain a novel high-temperature resistant thermal environmental barrier coating.

[0026] In one or some possible embodiments, in step S2, the deposition conditions of the bonding layer are: argon flow rate of 25 to 45 L / min, hydrogen flow rate of 5 to 10 L / min, spraying distance of 80 to 120 mm, spraying current of 500 to 800 A, particle size of Si-MSi2 powder used for spraying is 50 to 125 μm, and powder feeding rate is 3-8%.

[0027] In one or some possible embodiments, in step S3, the deposition conditions of the environmental barrier coating are: argon flow rate of 30 to 60 L / min, hydrogen flow rate of 7 to 16 L / min, spraying distance of 90 to 150 mm, spraying current of 600-900 A, the particle size of Yb2Si2O7 and / or Yb2SiO5 powder used for spraying is 30-140 μm, and the powder feeding rate is 5-15%.

[0028] In one or some possible embodiments, in step S4, the deposition conditions of the surface thermal barrier coating are: argon flow rate of 30-60 L / min, hydrogen flow rate of 5-15 L / min, spraying distance of 100-150 mm, spraying current of 500-1000 A, and Yb3Al5O 12 The particle size of the powder is 30-120 μm, and the powder feeding rate is 5-10%.

[0029] The novel high-temperature thermal environment resistant barrier coating and its preparation method of the present invention have the following beneficial effects compared with the prior art:

[0030] (1) The novel bonding layer material for high-temperature resistant thermal barrier coating prepared by the present invention is prepared by introducing MSi2, which is oxidized at high temperature to generate M2O3, which then reacts with SiO2 in TGO to form M2Si2O7. This product not only consumes part of SiO2 to alleviate the volume effect, but also has a low thermal expansion coefficient (~4.0×10 -6 / K) can also bridge the thermal expansion gradient between layers, significantly improve the interface compatibility, inhibit stress accumulation during thermal cycling, and thus improve the coating bonding strength.

[0031] (2) The new high-temperature thermal environment barrier coating prepared by the present invention adopts the Si-MSi2 layer to replace the Si layer in the traditional system, which can significantly improve the high-temperature resistance of the coating and is suitable for more severe high-temperature environments.

[0032] (3) The new high-temperature resistant thermal environment barrier coating prepared by the present invention effectively solves the problem of insufficient high-temperature resistance of the bonding layer in the existing thermal environment barrier coating system. It is not easy to react with the substrate to form a low-melting-point SiO2 transition layer under high-temperature (>1300°C) environment, effectively suppressing the phenomenon of interface degradation and improving the long-term stability and service life of the coating under extreme high-temperature working conditions.

[0033] (4) When the Si-MSi2 bonding layer provided by the present invention is compounded with a substrate, under the premise of no EBC (environmental barrier coating) and TBC (surface thermal barrier coating) protection, the thermal cycle life of the coating is not less than 200 times under the same test conditions, which is significantly better than the thermal cycle number of the coating made of traditional pure Si bonding layer (less than 100 times), showing more excellent thermal cycle resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a schematic structural diagram of a novel high-temperature thermal environment barrier coating prepared in Example 1 of the present invention;

[0036] Figure 2 Schematic diagram of a thermal cycle model for thermal cycle performance testing of the present invention;

[0037] Figure 3 This is a comparison diagram of the substrate / adhesive layer materials prepared in Example 1 of the present invention and Comparative Example 1 under the same thermal ablation conditions;

[0038] Figure 4 Schematic diagram of the number of thermal cycles of the substrate / adhesive layer materials of Example 1 of the present invention and Comparative Example 1 under the same test conditions;

[0039] Figure 5 Schematic diagram of samples of bonding strength test of bonding layer materials of Example 1 and Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] The Si bonding layer in the existing thermal barrier coating system has weak high-temperature resistance. It is easy for the substrate to react to form a low-melting-point SiO2 transition layer in a higher temperature environment (>1300°C), accelerating interface degradation, making it difficult to achieve long-term and stable operation under extreme high-temperature conditions.

[0042] Therefore, the present invention provides a novel high-temperature resistant thermal environment barrier coating, comprising a substrate, and an adhesive layer, an environmental barrier coating, and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0043] The substrate is SiC f / SiC-CMCs substrate;

[0044] The bonding layer is a Si-MSi2 bonding layer, wherein the M is selected from one or more of Y, Mo, Hf, Nb, Ta, Re, and Ti.

[0045] In the embodiment of the present invention, the SiC f / SiC-CMCs substrate needs to be pre-treated, including: f The SiC / SiC-CMCs substrate was ground, sandblasted, ultrasonically cleaned and dried.

[0046] In a specific embodiment of the present invention, during the pretreatment process, the grinding medium is a 240-800 mesh diamond grinding wheel, and the grinding wheel speed is 100-240 r / min; the sandblasting medium is 40-150 mesh corundum sand, the compressed air pressure is 0.1-0.4 MPa; and the ultrasonic cleaning time is 10-15 minutes.

[0047] In the embodiment of the present invention, the pretreated SiC f The roughness of the SiC-CMCs substrate is 4-10 μm.

[0048] In one embodiment of the present invention, the bonding layer powder is prepared by drying the desired Si powder and MSi2 powder in an oven at 100°C for 6 hours and then mixing them in a stoichiometric ratio. The powder is then mixed with deionized water and zirconium oxide balls in a mass ratio of 1:2:2. The powder particles are refined and mixed uniformly through friction and collision. After ball milling for 72 hours, the powder is spray granulated to obtain a spherical or quasi-spherical powder. This powder is then sieved to obtain the desired particle size range of 32-125 μm for atmospheric plasma spraying.

[0049] In a specific embodiment of the present invention, when the bonding layer Si-MSi2 powder is mixed according to stoichiometric measurements, Si and water will slowly react during the mixing process to produce a small amount of Si(OH)4 gas. In order to ensure that there is no leakage, the mixing barrel needs to be opened every 4 to 6 hours for venting.

[0050] The technical solution of the present invention is further described below with reference to specific embodiments. Unless otherwise specified, the sources of materials and equipment in the embodiments are all commercially available conventional products.

[0051] Example 1

[0052] This embodiment provides a new high temperature thermal environment barrier coating, including SiC f / SiC-CMCs substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0053] The bonding layer is a Si-YSi2 bonding layer, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and a Yb2SiO5 environmental barrier coating in sequence, and the surface thermal barrier coating is a Yb3Al5O 12 Surface thermal barrier coating.

[0054] The novel high temperature resistant thermal environment barrier coating of this embodiment, such as Figure 1 As shown, it is prepared by the following steps:

[0055] (1) SiC f / SiC-CMCs substrate was pre-treated by grinding and sandblasting. The grinding process conditions were: 240 mesh diamond grinding wheel, grinding wheel speed was 200r / min; the sandblasting process conditions were: 150 mesh corundum sand, compressed air pressure was 0.1MPa; the roughness of SiC was detected by using a roughness meter. f / The surface roughness of SiC-CMCs substrate after pretreatment is 7 μm;

[0056] The pretreated SiC f The SiC / SiC-CMCs substrate was ultrasonically cleaned in 98% alcohol for 15 min and then dried at 120°C.

[0057] (2) Si-YSi2 bonding layer powder: The required Si powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) and YSi2 powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) were dried in an oven at 100°C for 6 hours, and then mixed in a ratio of Si / YSi2=50wt% / 50wt%. The powder was mixed with deionized water and zirconium oxide balls in a ratio of 1:2:2, and the powder particles were refined and mixed evenly through friction and collision, and ball milled at 300 rpm for 72 hours. In particular, when the bonding layer Si-YSi2 powder was mixed according to stoichiometric mixing, since Si and water would react slowly during the mixing process, in order to ensure that there was no leakage, the mixing barrel needed to be opened every 4 hours for venting.

[0058] (3) Using atmospheric plasma spraying technology on SiC that has been ultrasonically cleaned and dried f A Si-YSi2 bonding layer was prepared on the surface of the SiC-CMCs substrate. The thickness of the Si-YSi2 bonding layer was 100 μm, and the particle size of the Si-YSi2 powder used for spraying was 50-125 μm. The spraying process parameters were: spraying distance 80 mm, spraying current 500 A, powder feeding rate 3%, argon flow rate 30 L / min, and hydrogen flow rate 5 L / min.

[0059] (4) Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were sequentially prepared on the surface of the Si-YSi2 bonding layer by atmospheric plasma spraying technology. The thickness of the Yb2Si2O7 and Yb2SiO5 environmental barrier coatings was 50 μm, and the particle size of the Yb2Si2O7 and Yb2SiO5 powders used for spraying was 30-140 μm. The spraying process parameters were: spraying distance 90 mm, spraying current 600 A, powder feeding rate 5%, argon flow rate 40 L / min, and hydrogen flow rate 7 L / min.

[0060] (6) Preparation of Yb3Al5O on the surface of Yb2SiO5 environmental barrier coating by atmospheric plasma spraying technology 12 Surface thermal barrier coating, sprayed with Yb3Al5O 12 The thickness of the surface thermal barrier coating is 100 μm, Yb3Al5O 12 The powder particle size is 30-140 μm; the spraying process parameters are: spraying distance is 100 mm, spraying current is 600 A, powder feeding rate is 5%, argon flow rate is 40 L / min, and hydrogen flow rate is 7 L / min.

[0061] Use Figure 2 The thermal cycling equipment shown in the thermal cycling model schematic was used to test the thermal / environmental barrier coating used as a bonding layer for the novel high-temperature, thermal environment-resistant coating prepared in this example. The test conditions were: 1350°C in a tube furnace for 55 minutes, followed by air cooling for 5 minutes, until the coating area fell off by more than 10%, which was defined as failure. Specifically, the sample was heated to 1350°C in a tube furnace and held at this temperature for 5 minutes to ensure temperature stability and complete development of thermal stress. The sample was then quickly removed and immersed in room-temperature water and cooled for 2 minutes, causing rapid thermal contraction to simulate the thermal shock under extreme operating conditions. The sample was then wiped dry to prevent moisture from affecting the next high-temperature stage. The cycle was repeated, with the sample placed in the furnace again and heated, continuing the above process (each "1350°C hold + water cooling" cycle was defined as a complete cycle) until the mass loss of the block reached 10% of its total mass.

[0062] The results show that the thermal cycle life of the thermal / environmental barrier coating with the novel high-temperature thermal environment resistant bonding layer in the embodiment is 512 times.

[0063] Example 2

[0064] This embodiment provides a new high temperature thermal environment barrier coating, including SiC f / SiC-CMCs substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0065] The bonding layer is a Si-TiSi2 bonding layer, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and a Yb2SiO5 environmental barrier coating in sequence, and the surface thermal barrier coating is a Yb3Al5O 12 Surface thermal barrier coating.

[0066] The novel high-temperature thermal environment barrier coating of this embodiment is prepared by the following steps:

[0067] (1) SiC f / SiC-CMCs substrate was pre-treated by grinding and sandblasting. The grinding process conditions were: 400 mesh diamond grinding wheel, grinding wheel speed was 240r / min; the sandblasting process conditions were: 100 mesh corundum sand, compressed air pressure was 0.2MPa; the roughness of SiC was detected by using a roughness meter. f / The surface roughness of SiC-CMCs substrate after pretreatment is 10 μm;

[0068] The pretreated SiC f The SiC / SiC-CMCs substrate was ultrasonically cleaned in 98% alcohol for 12 min and dried at 120°C.

[0069] (2) Si-TiSi2 bonding layer powder: The required Si powder and TiSi2 powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) were dried in an oven at 100°C for 6 hours, and then mixed in a ratio of Si / TiSi2=50wt% / 50wt%. The powder was mixed with deionized water and zirconium oxide balls in a ratio of 1:2:2, and the powder particles were refined and mixed evenly through friction and collision, and ball milled at 300 rpm for 72 hours. In particular, when the bonding layer Si-TiSi2 powder was mixed according to stoichiometric mixing, since Si and water would react slowly during the mixing process, in order to ensure that there was no leakage, the mixing barrel needed to be opened every 5 hours for venting.

[0070] (3) Using atmospheric plasma spraying technology on SiC that has been ultrasonically cleaned and dried f A Si-TiSi2 bonding layer was prepared on the surface of the SiC-CMCs substrate. The thickness of the Si-TiSi2 bonding layer was 100 μm, and the particle size of the Si-TiSi2 powder used for spraying was 50-125 μm. The spraying process parameters were: spraying distance 80 mm, spraying current 500 A, powder feeding rate 3%, argon flow rate 40 L / min, and hydrogen flow rate 5 L / min.

[0071] (4) Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were sequentially prepared on the surface of the Si-TiSi2 bonding layer by atmospheric plasma spraying technology. The thickness of the Yb2Si2O7 and Yb2SiO5 environmental barrier coatings was 50 μm, and the particle size of the Yb2Si2O7 and Yb2SiO5 powders used for spraying was 30-140 μm. The spraying process parameters were: spraying distance 90 mm, spraying current 800 A, powder feeding rate 10%, argon flow rate 45 L / min, and hydrogen flow rate 10 L / min.

[0072] (5) Preparation of Yb3Al5O on the surface of Yb2SiO5 environmental barrier coating by atmospheric plasma spraying technology 12 Surface thermal barrier coating, sprayed with Yb3Al5O 12 The thickness of the surface thermal barrier coating is 100 μm, Yb3Al5O 12 The powder particle size is 30-140 μm; the spraying process parameters are: spraying distance is 120 mm, spraying current is 800 A, powder feeding rate is 10%, argon flow rate is 45 L / min, and hydrogen flow rate is 10 L / min.

[0073] The thermal / environmental barrier coating with the novel adhesive layer for high-temperature thermal environment coatings prepared in this example was subjected to thermal cycling performance testing. The test conditions were: 1350°C in a tube furnace for 55 minutes, followed by air cooling for 5 minutes, until the coating lost more than 10% of its area, which was considered failure. The results showed that the thermal / environmental barrier coating with the novel adhesive layer for high-temperature thermal environment coatings in this example had a thermal cycling life of 435 cycles.

[0074] Example 3

[0075] This embodiment provides a new high temperature thermal environment barrier coating, including SiC f / SiC-CMCs substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0076] The bonding layer is a Si-HfSi2 bonding layer, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and a Yb2SiO5 environmental barrier coating in sequence, and the surface thermal barrier coating is a Yb3Al5O 12 Surface thermal barrier coating.

[0077] The novel high-temperature thermal environment barrier coating of this embodiment is prepared by the following steps:

[0078] (1) SiC f / SiC-CMCs substrate was pre-treated by grinding and sandblasting. The grinding process conditions were: 800 mesh diamond grinding wheel, grinding wheel speed was 180r / min; sandblasting process conditions were: 40 mesh corundum sand, compressed air pressure was 0.4MPa; roughness tester was used to detect SiC f / The surface roughness of SiC-CMCs substrate after pretreatment is 4 μm;

[0079] The pretreated SiC f The SiC / SiC-CMCs substrate was ultrasonically cleaned in 98% alcohol for 10 min and dried at 120°C.

[0080] (2) Si-HfSi2 bonding layer powder: The required Si powder and HfSi2 powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) were dried in an oven at 100°C for 6 hours, and then mixed in a ratio of Si / HfSi2=50wt% / 50wt%. The powder was mixed with deionized water and zirconium oxide balls in a ratio of 1:2:2, and the powder particles were refined and mixed evenly through friction and collision, and ball milled at 300 rpm for 72 hours. In particular, when the bonding layer Si-HfSi2 powder was mixed according to stoichiometric mixing, since Si and water would react slowly during the mixing process, in order to ensure that there was no leakage, the mixing barrel needed to be opened every 6 hours for venting.

[0081] (3) Using atmospheric plasma spraying technology on SiC that has been ultrasonically cleaned and dried f A Si-HfSi2 bonding layer was prepared on the surface of the SiC-CMCs substrate. The thickness of the Si-HfSi2 bonding layer was 100 μm, and the particle size of the Si-HfSi2 powder used for spraying was 50-125 μm. The spraying process parameters were: spraying distance 120 mm, spraying current 800 A, powder feeding rate 3%, argon flow rate 45 L / min, and hydrogen flow rate 10 L / min.

[0082] (4) Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were sequentially prepared on the surface of the Si-HfSi2 bonding layer by atmospheric plasma spraying technology. The thickness of the Yb2Si2O7 and Yb2SiO5 environmental barrier coatings was 50 μm, and the particle size of the Yb2Si2O7 and Yb2SiO5 powders used for spraying was 30-140 μm. The spraying process parameters were: spraying distance 120 mm, spraying current 900 A, powder feeding rate 15%, argon flow rate 60 L / min, and hydrogen flow rate 16 L / min.

[0083] (5) Preparation of Yb3Al5O on the surface of Yb2SiO5 environmental barrier coating by atmospheric plasma spraying technology 12Surface thermal barrier coating, sprayed with Yb3Al5O 12 The thickness of the surface thermal barrier coating is 100 μm, Yb3Al5O 12 The powder particle size is 30-140 μm; the spraying process parameters are: spraying distance is 100 mm, spraying current is 1000 A, powder feeding rate is 8%, argon flow rate is 30 L / min, and hydrogen flow rate is 5 L / min.

[0084] The thermal / environmental barrier coating with the novel adhesive layer for high-temperature thermal environment coatings prepared in this example was subjected to thermal cycling performance testing. The test conditions were: 1350°C in a tube furnace for 55 minutes, followed by air cooling for 5 minutes, until the coating lost more than 10% of its area, which was considered failure. The results showed that the thermal / environmental barrier coating with the novel adhesive layer for high-temperature thermal environment coatings in this example had a thermal cycling life of 412 cycles.

[0085] Example 4

[0086] This embodiment provides a new high temperature thermal environment barrier coating, including SiC f / SiC-CMCs substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0087] The bonding layer is a Si-YSi2 bonding layer, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and a Yb2SiO5 environmental barrier coating in sequence, and the surface thermal barrier coating is a Yb3Al5O 12 Surface thermal barrier coating.

[0088] The novel high-temperature thermal environment barrier coating of this embodiment is prepared by the following steps:

[0089] (1) SiC f / SiC-CMCs substrate was pre-treated by grinding and sandblasting. The grinding process conditions were: 240 mesh diamond grinding wheel, grinding wheel speed was 200r / min; the sandblasting process conditions were: 150 mesh corundum sand, compressed air pressure was 0.1MPa; the roughness of SiC was detected by using a roughness meter. f / The surface roughness of SiC-CMCs substrate after pretreatment is 7 μm;

[0090] The pretreated SiC f The SiC / SiC-CMCs substrate was ultrasonically cleaned in 98% alcohol for 15 min and then dried at 120°C.

[0091] (2) Si-YSi2 bonding layer powder: The required Si powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) and YSi2 powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) were dried in an oven at 100°C for 6 hours, and then mixed in a ratio of Si / YSi2=80wt% / 20wt%. The powder was mixed with deionized water and zirconium oxide balls in a ratio of 1:2:2, and the powder particles were refined and mixed evenly through friction and collision, and ball milled at 300 rpm for 72 hours. In particular, when the bonding layer Si-YSi2 powder was mixed according to stoichiometric mixing, since Si and water would react slowly during the mixing process, in order to ensure that there was no leakage, the mixing barrel needed to be opened every 4 hours for venting.

[0092] (3) Using atmospheric plasma spraying technology on SiC that has been ultrasonically cleaned and dried f A Si-YSi2 bonding layer was prepared on the surface of the SiC-CMCs substrate. The thickness of the Si-YSi2 bonding layer was 50 μm, and the particle size of the Si-YSi2 powder used for spraying was 50-125 μm. The spraying process parameters were: spraying distance 120 mm, spraying current 800 A, powder feeding rate 8%, argon flow rate 25 L / min, and hydrogen flow rate 10 L / min.

[0093] (4) Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were sequentially prepared on the surface of the Si-YSi2 bonding layer by atmospheric plasma spraying technology. The thickness of the Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were both 100 μm, and the particle size of the Yb2Si2O7 and Yb2SiO5 powders used for spraying was 30-140 μm. The spraying process parameters were: spraying distance 150 mm, spraying current 900 A, powder feeding rate 15%, argon flow rate 30 L / min, and hydrogen flow rate 16 L / min.

[0094] (5) Preparation of Yb3Al5O on the surface of Yb2SiO5 environmental barrier coating by atmospheric plasma spraying technology 12 Surface thermal barrier coating, sprayed with Yb3Al5O 12 The thickness of the surface thermal barrier coating is 50 μm, Yb3Al5O 12 The powder particle size is 30-140 μm; the spraying process parameters are: spraying distance is 150 mm, spraying current is 1000 A, powder feeding rate is 10%, argon flow rate is 60 L / min, and hydrogen flow rate is 15 L / min.

[0095] Example 5

[0096] This embodiment provides a new high temperature thermal environment barrier coating, including SiC f / SiC-CMCs substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate;

[0097] The bonding layer is a Si-TiSi2 bonding layer, the environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and a Yb2SiO5 environmental barrier coating in sequence, and the surface thermal barrier coating is a Yb3Al5O 12 Surface thermal barrier coating.

[0098] The novel high-temperature thermal environment barrier coating of this embodiment is prepared by the following steps:

[0099] (1) SiC f / SiC-CMCs substrate was pre-treated by grinding and sandblasting. The grinding process conditions were: 400 mesh diamond grinding wheel, grinding wheel speed was 240r / min; the sandblasting process conditions were: 100 mesh corundum sand, compressed air pressure was 0.2MPa; the roughness of SiC was detected by using a roughness meter. f / The surface roughness of SiC-CMCs substrate after pretreatment is 10 μm;

[0100] The pretreated SiC f The SiC / SiC-CMCs substrate was ultrasonically cleaned in 98% alcohol for 12 min and dried at 120°C.

[0101] (2) Si-TiSi2 bonding layer powder: The required Si powder and TiSi2 powder (200 mesh, purity 99.9%, purchased from Beijing Huawei Ruike Chemical Technology Co., Ltd.) were dried in an oven at 100°C for 6 hours, and then mixed in a ratio of Si / TiSi2=70wt% / 30wt%. The powder was mixed with deionized water and zirconium oxide balls in a ratio of 1:2:2, and the powder particles were refined and mixed evenly through friction and collision, and ball milled at 300 rpm for 72 hours. In particular, when the bonding layer Si-TiSi2 powder was mixed according to stoichiometric mixing, since Si and water would react slowly during the mixing process, in order to ensure that there was no leakage, the mixing barrel needed to be opened every 6 hours for venting.

[0102] (3) Using atmospheric plasma spraying technology on SiC that has been ultrasonically cleaned and dried f A Si-TiSi2 bonding layer was prepared on the surface of the SiC-CMCs substrate. The thickness of the Si-TiSi2 bonding layer was 80 μm, and the particle size of the Si-TiSi2 powder used for spraying was 50-125 μm. The spraying process parameters were: spraying distance 120 mm, spraying current 800 A, powder feeding rate 8%, argon flow rate 45 L / min, and hydrogen flow rate 10 L / min.

[0103] (4) Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were sequentially prepared on the surface of the Si-TiSi2 bonding layer by atmospheric plasma spraying technology. The thickness of the Yb2Si2O7 and Yb2SiO5 environmental barrier coatings were 50 μm and 100 μm, respectively. The particle size of the Yb2Si2O7 and Yb2SiO5 powders used for spraying was 30-140 μm. The spraying process parameters were: spraying distance 150 mm, spraying current 600 A, powder feeding rate 5%, argon flow rate 60 L / min, and hydrogen flow rate 7 L / min.

[0104] (5) Preparation of Yb3Al5O on the surface of Yb2SiO5 environmental barrier coating by atmospheric plasma spraying technology 12 Surface thermal barrier coating, sprayed with Yb3Al5O 12 The thickness of the surface thermal barrier coating is 80 μm, Yb3Al5O 12 The powder particle size is 30-140 μm; the spraying process parameters are: spraying distance is 100 mm, spraying current is 500 A, powder feeding rate is 5%, argon flow rate is 30 L / min, and hydrogen flow rate is 5 L / min.

[0105] Comparative Example 1

[0106] The difference from Example 1 is that the bonding layer is a Si bonding layer, and the other conditions remain unchanged.

[0107] The thermal barrier coating prepared in this comparative example was subjected to thermal cycling performance testing. The test conditions remained the same as in Example 1. The results showed that the thermal / environmental barrier coating with a conventional Si bonding layer in the comparative example had a thermal cycling lifespan of 325 cycles, significantly lower than the thermal / environmental barrier coating with the novel high-temperature-resistant thermal environment coating bonding layer.

[0108] Taking the adhesive layer materials provided in Example 1 and Comparative Example 1 as an example, thermal ablation experiments were conducted after compounding with the substrate. Figure 3 shown.

[0109] Depend on Figure 3 It can be seen that under the same thermal ablation conditions, the substrate / adhesive layer system obtained in Example 1 is more resistant to high temperatures and produces fewer cracks under the same ablation conditions.

[0110] Take 3 portions of the bonding layer materials provided in Example 1 and Comparative Example 1 as examples, and f The sample prepared after compounding with SiC-CMCs substrate was kept at 1350℃ for 5 minutes, then taken out and quickly cooled in water for 2 minutes. The number of thermal cycles was as follows: Figure 4 shown.

[0111] Depend on Figure 4It can be seen that compared with Si samples (Si①, Si②, Si③, with thermal cycle times of 85, 82, and 86 respectively), Si-YSi samples (Si-YSi2①, Si-YSi2②, Si-YSi2③) showed significantly higher thermal cycle life (201, 243, and 226 respectively) under the same thermal cycle conditions. Their thermal cycle times are almost 2.5 to 3 times that of pure Si samples. This result shows that Si-YSi2 samples can significantly improve the thermal shock resistance of materials under extreme thermal cycle conditions.

[0112] Taking the bonding layer materials of Example 1 and Comparative Example 1 as an example, a bonding strength test was performed after compounding the Yb2Si2O7 environmental barrier coating. The test method includes the following steps:

[0113] (1) First, a high-purity graphite sheet with a size of 10 mm × 10 mm × 2 mm was selected as a temporary substrate material. The graphite surface was polished to enhance the adhesion of the coating. A bonding layer and a surface material were sequentially deposited on the surface of the graphite substrate. The bonding layer was divided into two groups: one group was a single Si bonding layer and the other group was a Si-YSi2 bonding layer, both with a thickness of 50 μm. A Yb2Si2O7 environmental barrier coating was then sprayed on top of the coating with a thickness of 50 μm. The deposition method was a plasma spraying process. The specific process parameters can be found in the above text.

[0114] (2) After the deposition is completed, the sample is placed in a static air atmosphere and heat treated at 1300 ° C for 10 hours to improve the density of the coating and promote interface bonding. After the heat treatment is completed, it is cooled to room temperature. Then, the graphite matrix is completely removed by mechanical means (such as sandpaper polishing), leaving only the complete Yb2Si2O7 / bonding layer double layer structure as the bonding strength test sample, such as Figure 5 shown.

[0115] (3) During the test, use high-temperature epoxy glue or ceramic glue to bond the upper and lower surfaces of the sample to a metal tensile fixture, with the upper fixture bonding the Yb2Si2O7 layer and the bottom fixture bonding the bonding layer. After bonding, keep the sample at 150°C for 2 hours to complete the curing. The bond strength test is performed using an electronic universal material testing machine with a tensile rate set at 0.5 mm / min. The maximum breaking load is recorded and the bond strength is calculated. The number of samples in each test group should be no less than 5 to improve data reliability.

[0116] The test results show that the average bond strength of samples containing a Si bond layer is lower than that of samples containing a Si-YSi2 bond layer. The fracture sites of these samples are mostly concentrated at the interface, showing a certain degree of interfacial delamination. In contrast, the fracture sites of the Si-YSi2 bond layer samples mainly occur within the coating, indicating good interfacial bonding. This indicates that the Si-YSi2 bond layer significantly improves the bond strength between the Si-YSi2 bond layer and the Yb2Si2O7 environmental barrier coating.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A novel bonding layer material for high temperature resistant thermal environment barrier coating, characterized in that: The bonding layer material is Si-MSi2, wherein the M is selected from one or more of Y, Mo, Hf, Nb, Ta, Re, and Ti.

2. The novel bonding layer material for high temperature resistant thermal environment barrier coating according to claim 1, characterized in that: Calculated by the mass percentage of the bonding layer material, the amount of MSi2 is 20 to 50 wt%.

3. A method for preparing the novel bonding layer material for high temperature resistant thermal environment barrier coating according to claim 2, characterized in that: The following steps are involved: After drying Si powder and MSi2 powder respectively, they are mixed according to the mass percentage, ball milled, and then spray granulated to obtain Si-MSi2 bonding layer material with a particle size of 32 to 125 μm.

4. Use of the novel bonding layer material for high-temperature resistant thermal environment barrier coating according to claim 1 or 2 in thermal environment barrier coating.

5. A new type of high temperature thermal environment barrier coating, characterized in that: The invention comprises a substrate, and a bonding layer, an environmental barrier coating and a surface thermal barrier coating sequentially deposited on the surface of the substrate; The substrate is SiC f / SiC-CMCs substrate; The bonding layer comprises the new bonding layer material for high-temperature thermal environment barrier coating according to claim 1 or 2.

6. The novel high temperature resistant thermal environment barrier coating according to claim 5, characterized in that: The thickness of the bonding layer is 50 to 100 μm; The environmental barrier coating includes a Yb2Si2O7 environmental barrier coating and / or a Yb2SiO5 environmental barrier coating, and the thickness of any of the environmental barrier coatings is 50 to 100 μm; The surface thermal barrier coating is selected from Yb3Al5O with a thickness of 50 to 100 μm. 12 Surface thermal barrier coating.

7. A method for preparing the novel high-temperature thermal environment barrier coating according to claim 5 or 6, characterized in that: The following steps are involved: S1. Pre-treating the substrate; S2, depositing a bonding layer on the surface of the substrate; S3, depositing an environmental barrier coating on the surface of the bonding layer; S4. Depositing a surface thermal barrier coating on the surface of the environmental barrier coating to obtain a novel high-temperature resistant thermal environmental barrier coating.

8. The method for preparing the novel high-temperature thermal environment barrier coating according to claim 7, characterized in that: In step S2, the deposition conditions of the bonding layer are: argon flow rate of 25-45 L / min, hydrogen flow rate of 5-10 L / min, spraying distance of 80-120 mm, spraying current of 500-800 A, particle size of Si-MSi2 powder used for spraying of 50-125 μm, and powder feeding rate of 3-8%.

9. The method for preparing the novel high-temperature thermal environment barrier coating according to claim 7, wherein: In step S3, the deposition conditions of the environmental barrier coating are as follows: argon flow rate is 30-60 L / min, hydrogen flow rate is 7-16 L / min, spraying distance is 90-150 mm, spraying current is 600-900 A, the particle size of Yb2Si2O7 and / or Yb2SiO5 powder used for spraying is 30-140 μm, and the powder feeding rate is 5-15%.

10. The method for preparing a novel high-temperature thermal environment barrier coating according to claim 7, wherein: In step S4, the deposition conditions of the surface thermal barrier coating are as follows: argon flow rate of 30-60 L / min, hydrogen flow rate of 5-15 L / min, spraying distance of 100-150 mm, spraying current of 500-1000 A, and Yb3Al5O 12 The particle size of the powder is 30-120 μm, and the powder feeding rate is 5-10%.

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