A method for preparing a fine-porous zirconia coating
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-29
- Publication Date
- 2026-08-14
AI Technical Summary
[0003]现有的纳米氧化锆涂层，如图1所示，显微组织孔径大，使用过程中，氧沿着大孔进入氧化锆涂层与粘接层界面中容易生成氧化物（TGO），导致纳米氧化锆涂层的强度底、弯曲后表面边缘处会大面积剥落
[0016]本发明的有益效果在于：本申请获得的细密孔氧化锆涂层的组织均匀，孔径在1μm~45μm之间，孔径整体分布均匀，无裂纹、分层，结合强度值为20.68~25.21Mpa之间；弯曲时，涂层结合牢固，边缘没有脱落且无明显的贯穿性裂纹产生；在800℃下热震25次后，涂层没有脱落、裂纹、起皮的现象，解决了现有纳米氧化锆涂层显微组织孔径大，容易生成氧化物，导致纳米氧化锆涂层的强度底、弯曲后表面边缘处会大面积剥落的问题。
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Figure CN122564448A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for preparing a fine-pore zirconia coating, belonging to the field of thermal barrier coating technology. Background Technology
[0002] Thermal barrier coatings are required on the surfaces of hot-end components in aero-engines and gas turbines to improve thermal cycle life. Zirconia (YSZ) is a suitable thermal barrier coating material due to its advantages such as low thermal conductivity, high coefficient of thermal expansion, and high strain toughness.
[0003] Existing nano-zirconia coatings, such as Figure 1 As shown, the microstructure has large pore size. During use, oxygen enters the interface between the zirconia coating and the adhesive layer along the large pores and easily generates oxides (TGO), resulting in low strength of the nano-zirconia coating and large-area peeling at the surface edge after bending. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a method for preparing a fine-pore zirconia coating.
[0005] The present invention is achieved through the following technical solutions.
[0006] The present invention provides a method for preparing a fine-porous zirconia coating, comprising: The preparation process of fine-pore zirconia coating with a pore size of 1μm~45μm that can withstand 25 thermal shocks at 800℃.
[0007] The preparation process includes four steps performed sequentially: powder preparation, pretreatment, coating preparation, and coating performance testing.
[0008] The powder preparation stage involves the following steps: titrating 8% yttrium-stabilized zirconia spherical powder using a hydrothermal process. The zirconia spherical powder has the composition ZrO28Y2O3 and a particle size of 15~45μm. Before spraying, any trapped moisture is removed.
[0009] The pretreatment stage steps are as follows: the substrate is subjected to sandblasting activation treatment to achieve a roughness of Ra 2.0~3.8μm.
[0010] During the sandblasting activation treatment, the sandblasting pressure is 0.4 MPa, the sandblasting time is 5~10 min, the sandblasting angle is 50~75°, and the sandblasting distance is 90~130 mm; acetone + ultrasonic cleaning at 30°C removes excessive embedded sand particles for 15 min.
[0011] The coating preparation stage involves the following steps: first, an adhesive layer NiCrAlCoY2O3 is prepared on the sandblasted surface of the substrate using atmospheric plasma spraying, and then a nano-zirconia (YSZ) coating is prepared on the surface of the adhesive layer.
[0012] The preparation parameters for the adhesive layer are as follows: Ar flow rate 40 L / min, H2 flow rate 10 L / min, power 47 kW, powder feed rate 50 g / min, powder feed distance 8-10 mm, powder feed angle 90°, powder feed needle diameter 1.8 mm, spraying distance 150-160 mm, linear velocity 1-1.1 m / s, and coating thickness 0.10-0.20 mm.
[0013] The preparation parameters for the nano-zirconia coating are as follows: Ar flow rate 35 L / min, H2 flow rate 17 L / min, power 54 kW, powder feed rate 25 g / min, powder feed distance 3-4 mm, powder feed angle 90°, powder feed needle diameter 1.5 mm, spraying distance 120-140 mm, linear velocity 1-1.1 m / s, and coating thickness 0.10-0.20 mm.
[0014] The coating performance testing stage involves the following steps: testing the microstructure, bonding strength, bending properties, and thermal shock resistance of the prepared sample.
[0015] The surface roughness Ra of the fine-porous zirconia coating is 4.1~5.0 μm.
[0016] The beneficial effects of this invention are as follows: The fine-pore zirconia coating obtained in this application has a uniform structure with pore sizes between 1 μm and 45 μm. The pore size is uniformly distributed throughout the coating, without cracks or delamination, and the bonding strength is between 20.68 and 25.21 MPa. When bent, the coating is firmly bonded, with no edge peeling and no obvious through cracks. After 25 thermal shocks at 800°C, the coating does not peel, crack, or flake. This solves the problem that existing nano-zirconia coatings have large microstructure pore sizes, are prone to oxide formation, resulting in low strength and large-area peeling at the surface edges after bending. Attached Figure Description
[0017] Figure 1 This is a microstructure diagram of existing zirconia coatings; Figure 2 This is a microstructure diagram of the zirconium oxide coating of the present invention; Figure 3 This is a surface state diagram of the zirconia coating of the present invention under bending test performance with the substrate; Figure 4 This is a surface state diagram of the zirconium oxide coating of the present invention after being subjected to 25 thermal shock tests at 800°C along with the substrate; Detailed Implementation
[0018] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.
[0019] The present application discloses a method for preparing a fine-porous zirconia coating, comprising the following steps.
[0020] Step 1, Powder preparation stage: 8% yttrium oxide stabilized zirconia spherical powder (ZrO28Y2O3) is titrated using a hydrothermal process, with a particle size of 15~45μm. Before spraying, it is placed in an oven at 70℃ for more than 2 hours to remove moisture trapped in the powder particles.
[0021] Step 2, Pretreatment stage: The matrix is activated by sandblasting with 36# white fused alumina sand to achieve a roughness of Ra 2.0~3.8μm; During the sandblasting activation treatment, the sandblasting pressure is 0.4MPa, the sandblasting time is 5~10min, the sandblasting angle is 50~75°, and the sandblasting distance is 90~130mm; acetone + ultrasonic cleaning at 30℃ removes excess embedded sand particles for 15min.
[0022] Step 3, Coating preparation stage: First, an adhesive layer NiCrAlCoY2O3 is prepared on the sandblasted surface of the substrate using atmospheric plasma spraying, and then a nano-zirconia (YSZ) coating is prepared on the surface of the adhesive layer. The preparation parameters for the adhesive layer are as follows: Ar flow rate 40 L / min, H2 flow rate 10 L / min, power 47 kW, powder feed rate 50 g / min, powder feed distance 8~10 mm, powder feed angle 90°, powder feed needle diameter 1.8 mm, spraying distance 150~160 mm, linear velocity 1~1.1 m / s, and coating thickness 0.10~0.20 mm. The preparation parameters for the nano-zirconia coating are as follows: Ar flow rate 35 L / min, H2 flow rate 17 L / min, power 54 kW, powder feed rate 25 g / min, powder feed distance 3~4 mm, powder feed angle 90°, powder feed needle diameter 1.5 mm, spraying distance 120~140 mm, linear velocity 1~1.1 m / s, and coating thickness 0.10~0.20 mm.
[0023] Step 4, Coating Performance Testing Stage: The prepared samples are tested for microstructure, bonding strength, bending properties, and thermal shock resistance.
[0024] The technical solution of this application yields a microstructure of a fine-pored zirconia coating, see [see details]. Figure 2 ,from Figure 2 As can be seen, the microstructure is uniform, and the pore size of the fine-pored zirconia coating is between 1μm and 45μm. The overall pore size is uniformly distributed, and there are no cracks, delamination or other phenomena.
[0025] The bonding strength of the fine-pore zirconia coating obtained by the technical solution of this application is about 23 MPa, as shown in Table 1; Table 1 shows the test data for the bonding strength of the porous nano-zirconia (YSZ) coating.
[0026] Table 1 demonstrates that the presence of fine pores in the microporous zirconia coating does not reduce the coating's bonding strength, thus meeting the requirement of a bonding strength ≥15 MPa for general nano zirconia (YSZ).
[0027] The technical solution of this application achieves the bending properties of a fine-pore zirconia coating, see... Figure 3 The bending diameter is 12.7mm, and the bending angle is ≥90°. Figure 3 The results show that the coating at the curved surface R is firmly bonded, with no edge peeling and no obvious through cracks.
[0028] The technical solution of this application achieves the thermal shock resistance of a fine-pore zirconia coating, see... Figure 4 After 25 thermal shocks at 800℃, the coating did not peel off, crack, or flake, proving that this fine-pore zirconia (YSZ) coating has good thermal shock resistance. Because the small and dense pores cause the coating to shrink as a whole during thermal shock, the strain tolerance is sufficient.
[0029] The surface roughness of the fine-pore zirconia coating obtained by the technical solution of this application is shown in Table 2; Table 2 shows the surface roughness test data of the porous nano-zirconia coating.
[0030] As shown in Table 2, the surface roughness Ra of the fine-pore zirconia coating is 4.1~5.0 μm. This low surface roughness can extend the erosion life of the zirconia (YSZ) coating under high-speed and high-temperature airflow.
Claims
1. A method for preparing a fine-porous zirconia coating, characterized in that, include: The preparation process of fine-pore zirconia coating with a pore size of 1μm~45μm that can withstand 25 thermal shocks at 800℃.
2. The method for preparing a fine-porous zirconia coating as described in claim 1, characterized in that: The preparation process includes four steps performed sequentially: powder preparation, pretreatment, coating preparation, and coating performance testing.
3. The method for preparing a fine-porous zirconia coating as described in claim 2, characterized in that, The powder preparation stage involves the following steps: titrating 8% yttrium-stabilized zirconia spherical powder using a hydrothermal process. The zirconia spherical powder has the composition ZrO28Y2O3 and a particle size of 15~45μm. Before spraying, any trapped moisture is removed.
4. The method for preparing a fine-porous zirconia coating as described in claim 2, characterized in that, The pretreatment stage steps are as follows: the substrate is subjected to sandblasting activation treatment to achieve a roughness of Ra 2.0~3.8μm.
5. The method for preparing a fine-porous zirconia coating as described in claim 4, characterized in that, During the sandblasting activation treatment, the sandblasting pressure is 0.4 MPa, the sandblasting time is 5~10 min, the sandblasting angle is 50~75°, and the sandblasting distance is 90~130 mm; acetone + ultrasonic cleaning at 30°C removes excessive embedded sand particles for 15 min.
6. The method for preparing a fine-porous zirconia coating as described in claim 2, characterized in that, The coating preparation stage involves the following steps: first, an adhesive layer NiCrAlCoY2O3 is prepared on the sandblasted surface of the substrate using atmospheric plasma spraying, and then a nano-zirconia (YSZ) coating is prepared on the surface of the adhesive layer.
7. The method for preparing a fine-porous zirconia coating as described in claim 6, characterized in that, The preparation parameters for the adhesive layer are as follows: Ar flow rate 40 L / min, H2 flow rate 10 L / min, power 47 kW, powder feed rate 50 g / min, powder feed distance 8-10 mm, powder feed angle 90°, powder feed needle diameter 1.8 mm, spraying distance 150-160 mm, linear velocity 1-1.1 m / s, and coating thickness 0.10-0.20 mm.
8. The method for preparing a fine-porous zirconia coating as described in claim 6, characterized in that, The preparation parameters for the nano-zirconia coating are as follows: Ar flow rate 35 L / min, H2 flow rate 17 L / min, power 54 kW, powder feed rate 25 g / min, powder feed distance 3-4 mm, powder feed angle 90°, powder feed needle diameter 1.5 mm, spraying distance 120-140 mm, linear velocity 1-1.1 m / s, and coating thickness 0.10-0.20 mm.
9. The method for preparing a fine-porous zirconia coating as described in claim 2, characterized in that, The coating performance testing stage involves the following steps: testing the microstructure, bonding strength, bending properties, and thermal shock resistance of the prepared sample.
10. The method for preparing a fine-porous zirconia coating as described in claim 2, characterized in that, The surface roughness Ra of the fine-porous zirconia coating is 4.1~5.0 μm.