Powder for crystallizer copper plate coating

Abstract

The invention relates to the technical field of spraying, and provides powder for a crystallizer copper plate coating, which is composed of the following raw materials in percentage by weight: 0.5%-1.0% of C, 2.0%-2.5% of Si, 0.1%-0.5% of Fe, 0.5%-1.5% of B, 1.8%-2.5% of Co, 15%-18% of W, 10.0%-12.0% of a reinforcing phase and the balance of Ni, and the reinforcing phase is composed of titanium nitride, silicon nitride and aluminum nitride in a mass ratio of 3: 2: (1-1.5). According to the technical scheme, the problem that the hardness of the coating formed by the powder for the crystallizer copper plate coating in the related technology is insufficient is solved.

Description

Technical Field

[0001] This invention relates to the field of spray coating technology, and more specifically, to a powder for coating copper plates in crystallizers. Background Technology

[0002] In numerous fields such as industrial manufacturing, electronics, medical devices, and aerospace, copper plates have always held an indispensable position due to their excellent electrical and thermal conductivity, good ductility, and machinability. However, pure copper plates inherently possess defects such as low surface hardness, poor wear resistance, and insufficient corrosion resistance. Under long-term conditions of friction, impact, or complex corrosive environments, they are prone to surface scratches, wear thinning, and even corrosion failure, severely shortening the service life of copper plate components and increasing equipment maintenance costs and safety hazards. To compensate for the performance shortcomings of pure copper plates, extend their service life, and expand their application scenarios, surface modification treatment of copper plates through coating technology has become a widely adopted key technology in the industry. Powder is used as the core raw material for preparing crystallizer copper plate coatings, and its performance directly determines the quality and performance of the final coating.

[0003] However, existing powder coatings for copper plates in crystallizers still lack sufficient hardness, failing to meet the requirements for high-hardness coatings in some applications. If the coating's hardness is insufficient, it is easily worn down by friction pairs under wear-resistant conditions, leading to rapid coating failure. This exposes the copper substrate, accelerating wear and corrosion, significantly shortening component lifespan, and increasing equipment downtime and replacement costs. In precision machining, low-hardness coatings struggle to resist cutting and impact forces during processing, easily resulting in scratches, dents, and other defects. This affects product machining accuracy and surface quality, leading to a decrease in product yield.

[0004] Therefore, it is essential to develop a powder for coating copper plates in crystallizers that can form a high-hardness coating. Summary of the Invention

[0005] This invention proposes a powder for coating copper plates of crystallizers, which solves the problem of insufficient coating hardness in the powder used for coating copper plates of crystallizers in related technologies.

[0006] The technical solution of the present invention is as follows: The present invention proposes a powder for coating copper plates of crystallizers, which is composed of the following raw materials in weight percentage: C 0.5%~1.0%, Si 2.0%~2.5%, Fe 0.1%~0.5%, B 0.5%~1.5%, Co 1.8%~2.5%, W 15%~18%, reinforcing phase 10.0%~12.0%, and the balance being Ni. The reinforcing phase is composed of titanium nitride, silicon nitride and aluminum nitride in a mass ratio of 3:2:1~1.5.

[0007] As a further technical solution, the raw material satisfies W / (C+B+Si) = 3.6~5.

[0008] In the powder used for the crystallizer copper plate coating of this invention, the raw materials satisfy the ratio of W / (C+B+Si) = 3.6~5. By balancing the ratio of high-hardness core elements and auxiliary reinforcing elements, the synergistic effect of each component on hardness is better utilized. W, as a key element for improving the hardness of the coating matrix, when its content is controlled in the ratio of C, B, and Si within the range of 3.6~5, it can ensure that sufficient W elements form high-hardness intermetallic compounds, laying the foundation for coating hardness; at the same time, appropriate amounts of C, B, and Si can promote the solid solution and dispersion distribution of W, avoiding the problem of uneven hardness caused by W element aggregation. Simultaneously, C, B, Si, W, and other alloying elements synergistically precipitate more hard phases, further densifying the coating structure and improving the hardness of the crystallizer copper plate coating.

[0009] As a further technical solution, the average particle size of the powder used for coating the copper plate of the crystallizer is 30~40μm.

[0010] The present invention also proposes a crystallizer copper plate coating, which is formed by powder spraying.

[0011] As a further technical solution, the spraying includes the following steps: S1. Sandblasting preparation: Use solvent to wipe away dirt and grease from the surface and sides of the copper plate, grind the surface and sides of the copper plate to remove the oxide layer and work-hardened layer, and obtain the pre-treated copper plate. S2, Sandblasting: The coating surface of the pretreated copper plate is sandblasted to obtain a sandblasted copper plate; S3. Spraying preheating: The sandblasted copper plate is heated to 50~60℃ to obtain a preheated copper plate. The coating of the crystallizer copper plate is made of powder according to the weight percentage, sintered and then crushed, and heated to 100~120℃ to obtain hot powder. S4. Spraying: The hot powder is sprayed onto the surface of the preheated copper plate using a supersonic flame spraying method to form a coating on the crystallizer copper plate.

[0012] As a further technical solution, the solvent includes one or more of acetone, anhydrous ethanol, xylene, acetone, and ethyl acetate.

[0013] As a further technical solution, the surface roughness of the copper plate after sandblasting is Ra15~Ra30μm.

[0014] As a further technical solution, the sintering is vacuum hot pressing sintering, the sintering temperature is 1400~1500℃, for example, 1400℃, 1420℃, 1440℃, 1450℃, 1460℃, 1480℃, 1500℃, preferably 1450℃; the sintering pressure is 20~40MPa, for example, 20MPa, 25MPa, 30MPa, 35MPa, 40MPa, preferably 30MPa; the vacuum degree of the sintering is 3.5×10 -3 ~4.5×10 -3 Preferably 4×10 -3 The heat preservation time is 1 to 3 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours, with 2 hours being the preferred time.

[0015] As a further technical solution, the thickness of the copper plate coating of the crystallizer is 0.55~1.05mm.

[0016] As a further technical solution, the solvent is composed of anhydrous ethanol, acetone and ethyl acetate in a mass ratio of 5~6:2:3.

[0017] Before spraying the coating on the copper plate of the crystallizer in this invention, a solvent is used to wipe away dirt and grease from the surface and sides of the copper plate. The solvent consists of anhydrous ethanol, acetone, and ethyl acetate. Anhydrous ethanol, with its excellent solubility and volatility, can quickly dissolve and remove surface dust and light oil stains. Acetone has a stronger degreasing ability and can remove stubborn grease, residual additives, and other contaminants. Ethyl acetate can help dissolve insoluble impurities and regulate the evaporation rate of the solvent system, avoiding residual water stains or dirt after wiping. Through the synergistic cleaning effect of this composite solvent, dirt and grease on the surface and sides of the copper plate can be thoroughly removed. At the same time, it slightly activates the oxide layer on the surface of the copper plate, reduces the interfacial impurity barrier between the coating and the substrate during the spraying process, improves the interfacial wettability between the coating powder and the copper plate substrate, and enhances the bonding strength between the coating and the copper plate.

[0018] The working principle and beneficial effects of this invention are as follows: The powder used for the copper plate coating of the crystallizer in this invention has a high content of W, which, as a high-hardness alloying component, can form stable intermetallic compounds with other elements, significantly improving the hardness of the coating matrix. C and B elements can promote the precipitation and refinement of the alloy phase, further enhancing the structural density and hardness of the coating; Co element can optimize the compatibility of each component, ensuring increased hardness while maintaining the structural stability of the coating. The addition of reinforcing phases formed by titanium nitride, silicon nitride, and aluminum nitride, with the synergistic effect of these three types of nitrides, creates dispersed hard reinforcing sites that form a strong metallurgical bond with the alloy matrix, significantly improving the overall hardness of the coating. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] In the following examples and comparative examples: Titanium nitride: particle size 20nm, purity 99.9%; Silicon nitride: particle size 20nm, purity 99.9%; Aluminum nitride: particle size 40nm, purity 99.9%; W: Particle size 0.5μm, purity 99.9%; Ni: Particle size 1μm, purity 99.9%; B: Particle size is 1μm, purity is 99.5%; Si: Particle size 80nm, purity 99.9%; Fe: Particle size 1μm, purity 99.9%; C: Particle size is 20nm, purity is 99.9%.

[0021] Example 1 A powder for coating copper plates in crystallizers is composed of the following raw materials by weight percentage: C 0.5%, Si 2.0%, Fe 0.1%, B 0.5%, Co 1.8%, W 15%, reinforcing phase 10.0%, and the balance being Ni, wherein the reinforcing phase is composed of titanium nitride, silicon nitride, and aluminum nitride in a mass ratio of 3:2:1; A coating for a crystallizer copper plate, the coating application comprising the following steps: S1. Sandblasting preparation: Wipe away dirt and grease from the surface and sides of the copper plate with anhydrous ethanol, grind the surface and sides of the copper plate to remove the oxide layer and work-hardened layer, and obtain the pretreated copper plate. S2. Sandblasting: The coating surface of the pretreated copper plate is sandblasted to obtain a sandblasted copper plate with a surface roughness of Ra15μm. S3. Preheating for Coating: The sandblasted copper plate is heated to 50°C to obtain a preheated copper plate. The coating powder for the crystallizer copper plate is then formulated according to the weight percentage and vacuum sintered at 1450°C with a vacuum degree of 4×10⁻⁶. -3 The pressure was 30MPa, and after holding at the temperature for 2 hours, it was crushed and heated to 100℃ to obtain hot powder. The particle size of the powder used for the coating of the copper plate of the crystallizer after crushing was 30μm. S4. Spraying: Hot powder is sprayed onto the surface of the preheated copper plate using a supersonic flame spraying method to form a crystallizer copper plate coating with a thickness of 0.8mm.

[0022] Example 2 A powder for coating copper plates in crystallizers is composed of the following raw materials by weight percentage: C 0.8%, Si 2.2%, Fe 0.3%, B 0.75%, Co 2.1%, W 16.5%, reinforcing phase 11.0%, and the balance being Ni, wherein the reinforcing phase is composed of titanium nitride, silicon nitride, and aluminum nitride in a mass ratio of 3:2:1; A coating for a crystallizer copper plate, the coating application comprising the following steps: S1. Sandblasting preparation: Wipe away dirt and grease from the surface and sides of the copper plate with anhydrous ethanol, grind the surface and sides of the copper plate to remove the oxide layer and work-hardened layer, and obtain the pretreated copper plate. S2. Sandblasting: The coating surface of the pretreated copper plate is sandblasted to obtain a sandblasted copper plate with a surface roughness of Ra15μm. S3. Preheating for Coating: The sandblasted copper plate is heated to 50°C to obtain a preheated copper plate. The coating powder for the crystallizer copper plate is then formulated according to the weight percentage and vacuum sintered at 1450°C with a vacuum degree of 4×10⁻⁶. -3 The pressure was 30MPa, and after holding at the temperature for 2 hours, it was crushed and heated to 100℃ to obtain hot powder. The particle size of the powder used for the coating of the copper plate of the crystallizer after crushing was 30μm. S4. Spraying: Hot powder is sprayed onto the surface of the preheated copper plate using a supersonic flame spraying method to form a crystallizer copper plate coating with a thickness of 0.8mm.

[0023] Example 3 A powder for coating copper plates in crystallizers is composed of the following raw materials by weight percentage: C 1.0%, Si 2.5%, Fe 0.5%, B 1.5%, Co 2.5%, W 18%, reinforcing phase 12.0%, and the balance being Ni, wherein the reinforcing phase is composed of titanium nitride, silicon nitride, and aluminum nitride in a mass ratio of 3:2:1; A coating for a crystallizer copper plate, the coating application comprising the following steps: S1. Sandblasting preparation: Wipe away dirt and grease from the surface and sides of the copper plate with anhydrous ethanol, grind the surface and sides of the copper plate to remove the oxide layer and work-hardened layer, and obtain the pretreated copper plate. S2. Sandblasting: The coating surface of the pretreated copper plate is sandblasted to obtain a sandblasted copper plate with a surface roughness of Ra15μm. S3. Preheating for Coating: The sandblasted copper plate is heated to 50°C to obtain a preheated copper plate. The coating powder for the crystallizer copper plate is then formulated according to the weight percentage and vacuum sintered at 1450°C with a vacuum degree of 4×10⁻⁶. -3The pressure was 30MPa, and after holding at the temperature for 2 hours, it was crushed and heated to 100℃ to obtain hot powder. The particle size of the powder used for the coating of the copper plate of the crystallizer after crushing was 30μm. S4. Spraying: Hot powder is sprayed onto the surface of the preheated copper plate using a supersonic flame spraying method to form a crystallizer copper plate coating with a thickness of 0.8mm.

[0024] Example 4 The difference between Example 4 and Example 2 is that the reinforcing phase is composed of titanium nitride, silicon nitride and aluminum nitride in a mass ratio of 3:2:1.5.

[0025] Example 5 Compared with Example 4, Example 5 differs in that the powder for coating the copper plate of the crystallizer is composed of the following raw materials by weight percentage: C 0.5%, Si 2.0%, Fe 0.3%, B 0.5%, Co 2.1%, W 18.0%, reinforcing phase 11.0%, and the balance being Ni.

[0026] Example 6 Compared with Example 4, Example 6 differs in that the powder for coating the copper plate of the crystallizer is composed of the following raw materials by weight percentage: C 1.0%, Si 2.5%, Fe 0.3%, B 1.5%, Co 2.1%, W 15.0%, reinforcing phase 11.0%, and the balance being Ni.

[0027] Example 7 The difference between Example 7 and Example 4 is that the solvent consists of anhydrous ethanol and acetone in a mass ratio of 5:2.

[0028] Example 8 The difference between Example 8 and Example 4 is that the solvent consists of anhydrous ethanol and ethyl acetate in a mass ratio of 5:3.

[0029] Example 9 The difference between Example 9 and Example 4 is that the solvent consists of acetone and ethyl acetate in a mass ratio of 2:3.

[0030] Example 10 The difference between Example 10 and Example 4 is that the solvent consists of anhydrous ethanol, acetone and ethyl acetate in a mass ratio of 5:2:3.

[0031] Example 11 The difference between Example 11 and Example 4 is that the solvent consists of anhydrous ethanol, acetone and ethyl acetate in a mass ratio of 6:2:3.

[0032] Example 12 The difference between Example 12 and Example 4 is that the solvent consists of anhydrous ethanol, acetone and xylene in a mass ratio of 6:2:3.

[0033] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that the reinforcing phase is titanium nitride.

[0034] Comparative Example 2 Compared with Example 2, Comparative Example 2 differs in that the reinforcing phase is composed of titanium nitride and aluminum nitride in a mass ratio of 3:1.

[0035] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that the reinforcing phase is composed of silicon nitride and aluminum nitride in a mass ratio of 2:1.

[0036] Experimental Example 1 The Vickers hardness of the crystallizer copper plate coatings prepared in Examples 1-6 and Comparative Examples 1-3 was tested according to the Vickers hardness test method specified in GB / T 16534-2009 "Test Method for Room Temperature Hardness of Fine Ceramics".

[0037] The test results are shown in Table 1: Table 1 Performance test results of Examples 1-6 and Comparative Examples 1-3

[0038] As shown in Table 1, when a reinforcing phase composed of titanium nitride, silicon nitride and aluminum nitride is added to the powder for coating the copper plate of the crystallizer, the hardness of the coating can be improved. When the raw materials in the powder for coating the copper plate of the crystallizer meet the range and W / (C+B+Si)=3.6~5, the hardness of the coating can be further improved.

[0039] Experiment Example 2 For the copper plate coatings of the crystallizers prepared in Examples 4 and 7-12, the bonding strength between the coating and the copper plate was tested according to the test methods specified in T / CSEA 31-2023 "Thermal Spray Coating of Copper Plates for Continuous Casting Crystallizers".

[0040] The test results are shown in Table 2: Table 2 Performance test results of Examples 4 and 7-12

[0041] As shown in Table 2, wiping the surface and sides of the copper plate with a solvent composed of anhydrous ethanol, acetone and ethyl acetate in a mass ratio of 5~6:2:3 can improve the bonding strength between the coating and the copper plate.

[0042] The above are merely preferred embodiments of the present invention and are 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 within the protection scope of the present invention.

Claims

1. A powder for a crystallizer copper plate coating, characterized by, It is composed of the following raw materials by weight percentage: C 0.5%~1.0%, Si 2.0%~2.5%, Fe 0.1%~0.5%, B 0.5%~1.5%, Co 1.8%~2.5%, W 15%~18%, reinforcing phase 10.0%~12.0%, with the balance being Ni. The reinforcing phase is composed of titanium nitride, silicon nitride, and aluminum nitride in a mass ratio of 3:2:1~1.

5.

2. A powder for a copper plate coating of a crystallizer according to claim 1, characterized by The raw materials satisfy W / (C+B+Si) = 3.6~5.

3. The powder for a copper plate coating of a crystallizer according to claim 1, characterized by, The average particle size of the powder used for coating the copper plate of the crystallizer is 30~40μm.

4. A crystallizer copper plate coating, formed by powder spraying according to any one of claims 1 to 3.

5. A crystallizer copper plate coating according to claim 4, characterized in that, The spraying process includes the following steps: S1. Sandblasting preparation: Use solvent to wipe away dirt and grease from the surface and sides of the copper plate, grind the surface and sides of the copper plate to remove the oxide layer and work-hardened layer, and obtain the pre-treated copper plate. S2, Sandblasting: The coating surface of the pretreated copper plate is sandblasted to obtain a sandblasted copper plate; S3. Spraying preheating: The sandblasted copper plate is heated to 50~60℃ to obtain a preheated copper plate. The coating of the crystallizer copper plate is made of powder according to the weight percentage, sintered and then crushed, and heated to 100~120℃ to obtain hot powder. S4. Spraying: The hot powder is sprayed onto the surface of the preheated copper plate using a supersonic flame spraying method to form a coating on the crystallizer copper plate.

6. The crystallizer copper plate coating according to claim 5, characterized in that, In step S1, the solvent includes one or more of acetone, anhydrous ethanol, xylene, acetone, and ethyl acetate.

7. A crystallizer copper plate coating according to claim 5, characterized in that, In step S2, the surface roughness of the copper plate after sandblasting is Ra15~Ra30μm.

8. A crystallizer copper plate coating according to claim 5, characterized in that, In step S3, the sintering is vacuum hot-press sintering, the sintering temperature is 1400-1500℃, the sintering pressure is 20-40MPa, the sintering vacuum degree is 3.5×10 -3 ~4.5×10 -3 , and the holding time is 1-3h.

9. A crystallizer copper plate coating according to claim 5, characterized in that, The thickness of the copper plate coating of the crystallizer is 0.55~1.05mm.

10. A crystallizer copper plate coating according to claim 6, characterized in that, The solvent is composed of anhydrous ethanol, acetone and ethyl acetate in a mass ratio of 5~6:2:3.

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