A sprue for preparing nanocrystalline alloy strips, its preparation method and application

Abstract

This invention discloses a nozzle for preparing nanocrystalline alloy strips, its preparation method, and its application. The nozzle includes a SiC nozzle body and a ZrO2-CaO-C liner mounted on its inner surface, with a erosion-resistant composite coating covering the surface of the ZrO2-CaO-C liner. This invention solves the problems in existing technologies for preparing nanocrystalline alloy strips, such as SiC particles easily falling into the nanocrystalline master alloy molten steel, deposits easily forming on the inner wall of the nozzle leading to narrowing of the inner diameter, and microcracks easily appearing in the inner hole of the nozzle. It improves the cleanliness and fluidity of the nanocrystalline master alloy molten steel and greatly extends the service life of the nozzle.

Description

Technical Field

[0001] This invention relates to the technical field of preparing strip materials, and more particularly to the preparation technology of nanocrystalline alloy strip materials. Background Technology

[0002] Nanocrystalline alloy soft magnetic materials have seen rapid development in production and application in recent years due to their excellent electromagnetic properties, high saturation magnetic induction, high rectangularity ratio, high permeability, low loss, and stable performance, especially in the application of various high-quality core materials in switching power supplies and ISDN. Currently, nanocrystalline ribbons are mainly produced using the single-roll rapid quenching method. The preparation process is as follows: the nanocrystalline master alloy is placed in a vacuum medium-frequency furnace for remelting. After melting, the alloy molten steel is poured into a nozzle and heated. After being heated to 1400℃, the alloy molten steel flows out from the nozzle, passes through the nozzle nozzle cup, and is finally sprayed onto a high-speed rotating cooling copper roller for condensation, ultimately forming a nanocrystalline alloy ribbon with a thickness of 16-30 μm and a width of 10-75 mm. The nanocrystalline nozzle package sprue is one of the core components of the nanocrystalline alloy strip spraying production line. It is installed at the bottom of the nozzle package, and the flared end at the top of the sprue engages with a stopper rod. The flow rate of the master alloy molten steel is controlled by the up-and-down movement of the stopper rod. Its main function is to provide high-temperature molten steel with stable flow and pressure, maintaining the stability of the molten pool formed on the copper roller. The quality of the sprue directly affects the surface quality and yield of the nanocrystalline strip.

[0003] The existing sprue is integrally molded and made entirely of SiC. While it has the advantages of simple structure and low cost, it also has some drawbacks:

[0004] ① After one use, the nozzle body is flushed by 1400℃ alloy steel liquid, and its smooth protective layer has basically fallen off, exposing the rough SiC body. Under the continuous flushing of the steel liquid, the SiC particles on the body are easy to fall off and mix into the steel liquid, which not only contaminates the steel liquid, but also clogs the nozzle and affects the quality of the spraying.

[0005] ② During the spraying process, the aluminum in the master alloy steel melt reacts chemically with the oxygen drawn into the nozzle, and the product Al2O3 is deposited on the inner wall of the upper nozzle, which causes the inner diameter of the nozzle to narrow and the flow of the master alloy steel melt to be obstructed.

[0006] ③ To improve the resistance to molten steel erosion, the density of the SiC nozzle body needs to be increased, but the density needs to be increased to 3.7 g / cm³. 3 At this time, thermal shock stability becomes very poor, and fine cracks are easily formed after thermal shock, which reduces the corrosion resistance and lifespan. Summary of the Invention

[0007] The purpose of this invention is to provide a sprue for preparing nanocrystalline alloy strips, its preparation method and application, so as to solve the problems of short sprue life, steel contamination and affecting the quality of sprayed strips in the prior art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A sprue for preparing nanocrystalline alloy strips includes a SiC sprue body and a ZrO2-CaO-C liner assembled on its inner surface, with a layer of erosion-resistant composite coating covering the surface of the ZrO2-CaO-C liner.

[0010] Furthermore, a high-temperature adhesive is applied between the SiC sprue body and the ZrO2-CaO-C liner.

[0011] Furthermore, the thickness of the erosion-resistant composite coating is 0.4 mm to 0.9 mm.

[0012] Furthermore, the lower part of the nozzle body is provided with a nozzle body contact surface, a pressure ring contact surface, and a nozzle cup contact surface, and the flatness of the nozzle body contact surface, the pressure ring contact surface, and the nozzle cup contact surface is ≤0.05mm.

[0013] Furthermore, by weight,

[0014] The raw materials for the SiC nozzle body include:

[0015] 53-65 parts of coarse SiC, 26-35 parts of fine SiC, 1.5-3 parts of cellulose, 8-12 parts of aqueous solution, and 0.4-0.7 parts of glycerol;

[0016] The raw materials for the ZrO2-CaO-C lining include: 35-43 parts of coarse calcium zirconate, 18-26 parts of fine calcium zirconate, 20-33 parts of flake graphite, 2-6 parts of boron carbide, and 4-9 parts of phenolic resin.

[0017] The raw materials for the erosion-resistant composite coating include: 71-80 parts fused silica, 3-5 parts silica fume, 4-8 parts aluminate cement, and 10-15 parts aqueous solution.

[0018] Further, the SiC coarse material has a SiC mass fraction ≥98.32% and a particle size range of 0.1-1.2 mm; the SiC fine material has a SiC mass fraction ≥96.18% and a particle size range of 0.02-0.1 mm; the aqueous solution is prepared by adding 3.1%-4.8% by weight of polyvinyl alcohol to boiling purified water and stirring.

[0019] The coarse calcium zirconate has a particle size of 0.2–1 mm, the fine calcium zirconate has a particle size of 0–0.2 mm, and the flake graphite has a particle size of 0–1 mm.

[0020] This invention also provides a method for preparing a sprue for nanocrystalline alloy strips, comprising the following steps:

[0021] (1) Fabricate a high-strength sprue body mold and a high-strength inner lining pressing mold;

[0022] (2) Fabrication of SiC gate body:

[0023] ① Prepare the ingredients according to the weight ratio;

[0024] ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer;

[0025] ③ Stirring: Start the mixer to stir and obtain solid SiC board material;

[0026] ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring to obtain SiC board material slurry;

[0027] ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring to obtain the SiC gate body material, which is then sealed and stored.

[0028] ⑥ Molding: The SiC gate body material is added into a high-strength gate body mold, vibrated and sealed, and then formed in a multi-layer hot press to form a SiC gate body green blank.

[0029] ⑦ Sintering: The SiC gate body green blank is sintered at high temperature to obtain the SiC gate body;

[0030] (3) Preparation of ZrO2-CaO-C lining:

[0031] ① Prepare the ingredients according to the weight ratio;

[0032] ② Mixing: Add the lining raw materials to a high-speed mixer, and finally add phenolic resin. Mix evenly and then dry for later use.

[0033] ③ Molding: Add the mixed lining material into a high-strength lining mold, vibrate to compact and seal, and then mold in a multi-layer hot press to form a ZrO2-CaO-C lining green blank;

[0034] ④ Sintering: The ZrO2-CaO-C liner is sintered at high temperature to obtain the ZrO2-CaO-C liner;

[0035] (4) Preparation of erosion-resistant composite coatings:

[0036] The raw materials, including fused silica, silica fume, aluminate cement, and aqueous solution, are mixed evenly according to the weight ratio to obtain an erosion-resistant composite coating.

[0037] (5) An erosion-resistant composite coating is applied to the ZrO2-CaO-C lining:

[0038] ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining;

[0039] ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly;

[0040] ③ After molding, heat until dry.

[0041] (6) Assembly:

[0042] After the ZrO2-CaO liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body.

[0043] (7) Baking:

[0044] The sprue of the assembled nanocrystalline alloy strip is baked.

[0045] (8) Grind the nozzle body contact surface, pressure ring contact surface, and nozzle cup contact surface at the bottom of the sprue.

[0046] Furthermore, the detailed steps include:

[0047] (1) Fabricate a high-strength sprue body mold and a high-strength inner lining pressing mold;

[0048] (2) Fabrication of SiC gate body:

[0049] ① Prepare the ingredients according to the weight ratio;

[0050] ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer;

[0051] ③ Stirring: Start the mixer and stir for 22-24 minutes to obtain solid SiC board material;

[0052] ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring until the temperature reaches 31°C. The stirring time is 22-24 minutes to obtain SiC board material slurry.

[0053] ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring for 5 minutes to obtain the SiC sprue body material, and store it in a sealed container;

[0054] ⑥ Molding: Add the SiC gate body material into the high-strength gate body mold, vibrate to seal, and mold in a multi-layer hot press. The molding pressure is 62-67MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to form a SiC gate body green blank.

[0055] ⑦ Sintering: The SiC gate body green blank is sintered at 1540±20℃ for 9 to 10 hours to obtain the SiC gate body;

[0056] (3) Preparation of ZrO2-CaO-C lining:

[0057] ① Prepare the ingredients according to the weight ratio;

[0058] ② Mixing: Add the lining raw materials (calcium zirconate coarse material, calcium zirconate fine material, flake graphite, boron carbide) to a high-speed mixer, and finally add phenolic resin. After mixing evenly, dry for later use.

[0059] ③ Molding: Add the mixed lining material into a high-strength lining mold, vibrate to compact and seal, and then mold in a multi-layer hot press. The molding pressure is 115-119MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a ZrO2-CaO-C lining green blank.

[0060] ④ Sintering: The SiC sprue body green blank is sintered at 1540±20℃ for 10 to 12 hours to obtain ZrO2-CaO-C lining;

[0061] (4) Preparation of erosion-resistant composite coatings:

[0062] The raw materials, including fused silica, silica fume, aluminate cement, and aqueous solution, are mixed evenly according to the weight ratio to obtain an erosion-resistant composite coating.

[0063] (5) An erosion-resistant composite coating is applied to the ZrO2-CaO-C lining:

[0064] ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining;

[0065] ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly;

[0066] ③After molding, heat to 410℃ and dry.

[0067] (6) Assembly:

[0068] After the ZrO2-CaO liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body.

[0069] (7) Baking:

[0070] The assembled sprue of the nanocrystalline alloy strip was placed in a constant temperature drying oven at 220℃ and baked for 8 hours.

[0071] (8) Grind the nozzle body contact surface, pressure ring contact surface and nozzle cup contact surface at the bottom of the water inlet to make its flatness ≤0.05mm.

[0072] Furthermore, both the high-strength sprue body mold and the inner lining pressing mold are high-strength metal pressure molds.

[0073] The present invention also provides an application of the sprue obtained by the method in the preparation of nanocrystalline alloy strips.

[0074] The advantages of this invention include:

[0075] (1) This invention incorporates a ZrO2-CaO-C liner within the inner bore of the nozzle body, which possesses advantages such as high melting point, good thermodynamic stability, strong vacuum stability, excellent thermal shock resistance, and strong resistance to molten steel corrosion. This solves the problem of SiC particles easily detaching from the nozzle body and mixing into the nanocrystalline master alloy molten steel, ensuring the cleanliness of the nanocrystalline master alloy molten steel, preventing nozzle clogging, and thus improving the quality of the sprayed strip.

[0076] (2) In the ZrO2-CaO-C lining material, the calcium zirconate decomposes into CaO under the scouring of the nanocrystalline master alloy steel liquid at 1350℃. CaO reacts with Al2O3 in the water to form a low-melting-point phase. The low-melting-point phase makes the inner wall surface of the upper nozzle smooth and does not easily adhere. It can effectively eliminate the deposition of master alloy steel liquid on the inner wall of the upper nozzle, solve the problem of narrowing of the nozzle inner diameter, and ensure the fluidity of the nanocrystalline master alloy steel liquid.

[0077] (3) This invention improves service life by attaching a layer of erosion-resistant composite material to the ZrO2-CaO-C liner, thus avoiding the thermal shock effect of the first flush of the nanocrystalline master alloy steel. Specifically, by adding a composite material coating to the surface of the high-density ZrO2-CaO-C liner, direct contact between the molten steel and the ZrO2-CaO-C liner surface is avoided. Under the flushing of molten steel, the composite coating will slowly disappear within 12 to 14 minutes, thus providing 12 to 14 minutes of preheating time for the ZrO2-CaO-C liner and preventing the occurrence of microcracks. The high-density ZrO2-CaO-C liner without microcracks has excellent corrosion resistance and its service life is significantly increased by about 63%.

[0078] (4) The present invention has a simple structure, is easy to implement, and has low manufacturing cost. It can spray wider (80mm and above) and thinner (12-14μm) nanocrystalline alloy strips, making it suitable for widespread promotion and use. Attached Figure Description

[0079] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings:

[0080] Figure 1 This is a schematic diagram of the sprue cross-section structure for preparing nanocrystalline alloy strips;

[0081] Figure 2 This is a top view of the nozzle structure for preparing nanocrystalline alloy strips. Detailed Implementation

[0082] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0083] Example 1

[0084] like Figure 1 , 2 As shown, the present invention provides a sprue for preparing nanocrystalline alloy strips, comprising a SiC sprue body 1 and a ZrO2-CaO-C liner 2 assembled on its inner surface, and a layer of erosion-resistant composite coating 3 covering the surface of the ZrO2-CaO-C liner. The lower part of the SiC sprue body 1 is provided with a nozzle body contact surface 11, a pressure ring contact surface 12, and a nozzle cup contact surface 13. The flatness of the nozzle body contact surface 11, the pressure ring contact surface 12, and the nozzle cup contact surface 13 is ≤0.05mm. The thickness of the erosion-resistant composite coating 3 is 0.4mm to 0.9mm.

[0085] Example 2

[0086] (1) The high-strength sprue body mold and the high-strength inner lining pressing mold are both high-strength metal pressure molds.

[0087] (2) Fabrication of SiC gate body:

[0088] ① Prepare ingredients according to the weight ratio:

[0089] Serial Number Material Name Specification weight 1 SiC crude material (silicon carbide crude material) Particle size 0.1-1.2mm 63 2 SiC fines (silicon carbide fines) Particle size 0.02-0.1mm 26 3 cellulose —— 2.5 4 Aqueous solution —— 8 5 glycerin —— 0.5

[0090] ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer;

[0091] ③ Stirring: Start the mixer and stir for 22-24 minutes to obtain solid SiC board material;

[0092] ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring until the temperature reaches 31°C. The stirring time is 22-24 minutes to obtain SiC board material slurry.

[0093] ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring for 5 minutes to obtain the SiC sprue body material, and store it in a sealed container;

[0094] ⑥ Molding: Add the SiC gate body material into the high-strength gate body mold, vibrate to seal, and mold in a multi-layer hot press. The molding pressure is 62-67MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a SiC gate body green blank.

[0095] ⑦ Sintering: The SiC gate body green blank is sintered at 1540±20℃ for 9 to 10 hours to obtain the SiC gate body.

[0096] (3) Preparation of ZrO2-CaO-C lining:

[0097] ① Prepare ingredients according to the weight ratio:

[0098] Serial Number Material Name Specification weight 1 Calcium zirconate coarse material Particle size 0.2–1 mm 42 2 Calcium zirconate fines Particle size 0–0.2 mm 19 3 Flake graphite Particle size 0-1mm 30 4 Boron carbide —— 3 5 Phenolic resin —— 6

[0099] ② Mixing: Add the lining raw materials (calcium zirconate coarse material, calcium zirconate fine material, flake graphite, boron carbide) to a high-speed mixer, and finally add phenolic resin. After mixing evenly, dry for later use.

[0100] ③ Molding: Add the mixed lining material into a high-strength lining pressing mold, vibrate to compact and seal, and then mold in a multi-layer hot press. The molding pressure is 115-119MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a ZrO2-CaO-C lining green blank.

[0101] ④ Sintering: The ZrO2-CaO-C lining green body is sintered at 1540±20℃ for 10 to 12 hours to obtain the ZrO2-CaO-C lining.

[0102] (4) Production of erosion-resistant composite coatings:

[0103] ① Prepare ingredients according to the weight ratio:

[0104] Serial Number Material Name weight 1 Fused Quartz 79 2 silica ash 4 3 aluminate cement 6 4 Aqueous solution 11

[0105] ② Mixing: Mix the above raw materials evenly to obtain an erosion-resistant composite coating.

[0106] (5) An erosion-resistant composite coating is applied to the ZrO2-CaO-C lining:

[0107] ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining;

[0108] ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly;

[0109] ③After molding, heat to 410℃ and dry.

[0110] (6) Assembly:

[0111] After the ZrO2-CaO-C liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body.

[0112] (7) Baking:

[0113] The assembled sprue of the nanocrystalline alloy strip was placed in a constant temperature drying oven and baked at 220℃ for 8 hours.

[0114] (8) Finely grind the nozzle envelope contact surface, pressure ring contact surface, and nozzle cup contact surface at the bottom of the SiC sprue body to make its flatness ≤0.05mm.

[0115] The physical properties of the SiC nozzle body and the ZrO2-CaO-C lining, as tested, are as follows:

[0116]

[0117] Example 3

[0118] (1) The high-strength sprue body mold and the high-strength inner lining pressing mold are both high-strength metal pressure molds.

[0119] (2) Fabrication of SiC gate body:

[0120] ① Prepare ingredients according to the weight ratio:

[0121] Serial Number Material Name Specification weight 1 SiC crude material (silicon carbide crude material) Particle size 0.1-1.2mm 58 2 SiC fines (silicon carbide fines) Particle size 0.02-0.1mm 30 3 cellulose —— 2.4 4 Aqueous solution —— 9 5 glycerin —— 0.6

[0122] ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer;

[0123] ③ Stirring: Start the mixer and stir for 22-24 minutes to obtain solid SiC board material;

[0124] ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring until the temperature reaches 31°C. The stirring time is 22-24 minutes to obtain SiC board material slurry.

[0125] ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring for 5 minutes to obtain the SiC gate body material;

[0126] ⑥ Molding: Add the SiC gate body material into the high-strength gate body mold, vibrate to seal, and mold in a multi-layer hot press. The molding pressure is 62-67MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a SiC gate body green blank.

[0127] ⑦ Sintering: The SiC gate body green blank is sintered at 1540±20℃ for 9 to 10 hours to obtain the SiC gate body.

[0128] (3) Preparation of ZrO2-CaO-C lining:

[0129] ① Prepare ingredients according to the weight ratio:

[0130] Serial Number Material Name Specification weight 1 Calcium zirconate coarse material Particle size 0.2–1 mm 39 2 Calcium zirconate fines Particle size 0–0.2 mm 22 3 Flake graphite Particle size 0-1mm 28 4 Boron carbide —— 4 5 Phenolic resin —— 7

[0131] ② Mixing: Add the lining raw materials (calcium zirconate coarse material, calcium zirconate fine material, flake graphite, boron carbide) to a high-speed mixer, and finally add phenolic resin. After mixing evenly, dry for later use.

[0132] ③ Molding: Add the mixed lining material into a high-strength lining pressing mold, vibrate to compact and seal, and then mold in a multi-layer hot press. The molding pressure is 115-119MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a ZrO2-CaO-C lining green blank.

[0133] ④ Sintering: The ZrO2-CaO-C lining green body is sintered at 1540±20℃ for 10 to 12 hours to obtain the ZrO2-CaO-C lining.

[0134] (4) Production of erosion-resistant composite coatings:

[0135] ① Prepare ingredients according to the weight ratio:

[0136] Serial Number Material Name Quantity / portion 1 Fused Quartz 75 2 silica ash 5 3 aluminate cement 7 4 Aqueous solution 13

[0137] ② Mixing: Mix the above raw materials evenly to obtain an erosion-resistant composite coating.

[0138] (5) An erosion-resistant composite coating is applied to the ZrO2-CaO-C lining:

[0139] ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining;

[0140] ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly;

[0141] ③After molding, heat to 410℃ and dry.

[0142] (6) Assembly:

[0143] After the ZrO2-CaO-C liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body.

[0144] (7) Baking:

[0145] Place the sprue of the assembled nanocrystalline alloy strip into a constant temperature drying oven and bake at 220℃ for 8 hours.

[0146] (8) The nozzle envelope contact surface, pressure ring contact surface, and nozzle cup contact surface at the bottom of the SiC sprue body are finely ground, with a flatness of ≤0.05mm.

[0147] The physical properties of the SiC nozzle body and the ZrO2-CaO-C lining, as tested, are as follows:

[0148]

[0149]

[0150] Example 4

[0151] (1) The high-strength sprue body mold and the high-strength inner lining pressing mold are both high-strength metal pressure molds.

[0152] (2) Fabrication of SiC gate body:

[0153] ① Prepare ingredients according to the weight ratio:

[0154] Serial Number Material Name Specification weight 1 SiC crude material (silicon carbide crude material) Particle size 0.1-1.2mm 55 2 SiC fines (silicon carbide fines) Particle size 0.02-0.1mm 33 3 cellulose —— 1.8 4 Aqueous solution —— 9.5 5 glycerin —— 0.7

[0155] ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer;

[0156] ③ Stirring: Start the mixer and stir for 22-24 minutes to obtain solid SiC board material;

[0157] ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring until the temperature reaches 31°C. The stirring time is 22-24 minutes to obtain SiC board material slurry.

[0158] ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring for 5 minutes to obtain the SiC gate body material;

[0159] ⑥ Molding: Add the SiC gate body material into the high-strength gate body mold, vibrate to seal, and mold in a multi-layer hot press. The molding pressure is 62-67MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a SiC gate body green blank.

[0160] ⑦ Sintering: The SiC gate body green blank is sintered at 1540±20℃ for 9 to 10 hours to obtain the SiC gate body.

[0161] (3) Preparation of ZrO2-CaO-C lining:

[0162] ① Prepare ingredients according to the weight ratio:

[0163] Serial Number Material Name Specification Quantity / portion 1 Calcium zirconate coarse material Particle size 0.2–1 mm 36 2 Calcium zirconate fines Particle size 0–0.2 mm 24 3 Flake graphite Particle size 0-1mm 25 4 Boron carbide —— 6 5 Phenolic resin —— 9

[0164] ② Mixing: Add the lining raw materials (calcium zirconate coarse material, calcium zirconate fine material, flake graphite, boron carbide) to a high-speed mixer, and finally add phenolic resin. After mixing evenly, dry for later use.

[0165] ③ Molding: Add the mixed lining material into a high-strength lining mold, vibrate to compact and seal, and then mold in a multi-layer hot press. The molding pressure is 115-119MPa, the hot pressing temperature is 230-260℃, and the hot pressing time is 23-25 ​​minutes to press into a ZrO2-CaO-C lining green blank.

[0166] ④ Sintering: The ZrO2-CaO-C lining green body is sintered at 1540±20℃ for 10 to 12 hours to obtain the ZrO2-CaO-C lining.

[0167] (4) Fabrication of an erosion-resistant composite coating:

[0168] ① Prepare ingredients according to the weight ratio:

[0169]

[0170]

[0171] ② Mixing: Mix the above raw materials evenly to obtain an erosion-resistant composite coating.

[0172] (5) An erosion-resistant composite coating is applied to the ZrO2-CaO-C lining:

[0173] ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining;

[0174] ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly;

[0175] ③After molding, heat to 410℃ and dry.

[0176] (6) Assembly:

[0177] After the ZrO2-CaO-C liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body.

[0178] (7) Baking:

[0179] The assembled sprue of the nanocrystalline alloy strip was placed in a constant temperature drying oven and baked at 220℃ for 8 hours.

[0180] (8) The nozzle envelope contact surface, pressure ring contact surface, and nozzle cup contact surface at the bottom of the SiC sprue body are finely ground, with a flatness of ≤0.05mm.

[0181] The physical properties of the SiC nozzle body and the ZrO2-CaO-C lining, as tested, are as follows:

[0182]

[0183] The nozzle of this invention has excellent oxidation resistance, corrosion resistance and thermal shock resistance. It also has the advantages of being resistant to alloy steel slurry erosion, not easily shedding SiC particles, automatically removing deposits on the inner wall of the nozzle, and ensuring good steel slurry fluidity. It is especially suitable for spraying ultra-thin (12-14μm) wide (≥80mm) nanocrystalline alloy strips and is suitable for widespread promotion and use.

[0184] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A sprue for preparing nanocrystalline alloy strips, characterized in that: It includes a SiC nozzle body and a ZrO2-CaO-C liner assembled on its inner surface, and a layer of erosion-resistant composite coating covering the surface of the ZrO2-CaO-C liner. By weight, The raw materials for the SiC nozzle body include: 53-65 parts of coarse SiC, 26-35 parts of fine SiC, 1.5-3 parts of cellulose, 8-12 parts of aqueous solution, and 0.4-0.7 parts of glycerol; The raw materials for the ZrO2-CaO-C lining include: 35-43 parts of coarse calcium zirconate, 18-26 parts of fine calcium zirconate, 20-33 parts of flake graphite, 2-6 parts of boron carbide, and 4-9 parts of phenolic resin. The raw materials for the erosion-resistant composite coating include: 71-80 parts fused silica, 3-5 parts silica fume, 4-8 parts aluminate cement, and 10-15 parts aqueous solution; The SiC coarse material has a SiC mass fraction ≥ 98.32% and a particle size range of 0.1-1.2 mm; the SiC fine material has a SiC mass fraction ≥ 96.18% and a particle size range of 0.02-0.1 mm; the aqueous solution is prepared by adding 3.1%-4.8% by weight of polyvinyl alcohol to boiling purified water and stirring. The coarse calcium zirconate has a particle size of 0.2–1 mm, the fine calcium zirconate has a particle size of 0–0.2 mm, and the flake graphite has a particle size of 0–1 mm.

2. The nozzle for preparing nanocrystalline alloy strips according to claim 1, characterized in that: High-temperature adhesive is applied between the SiC sprue body and the ZrO2-CaO-C liner.

3. The nozzle for preparing nanocrystalline alloy strips according to claim 1, characterized in that: The thickness of the erosion-resistant composite coating is 0.4 mm to 0.9 mm.

4. The nozzle for preparing nanocrystalline alloy strips according to claim 1, characterized in that: The lower part of the nozzle body is provided with a nozzle body contact surface, a pressure ring contact surface, and a nozzle cup contact surface. The flatness of the nozzle body contact surface, the pressure ring contact surface, and the nozzle cup contact surface is ≤0.05 mm.

5. A method for preparing a sprue for nanocrystalline alloy strips as described in any one of claims 1-4, characterized in that: The steps include: (1) Fabricate a high-strength sprue body mold and a high-strength inner lining pressing mold; (2) Fabrication of SiC gate body: ① Prepare the ingredients according to the weight ratio; ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer; ③ Stirring: Start the mixer to stir and obtain solid SiC board material; ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring to obtain SiC board material slurry; ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring to obtain the SiC gate body material, which is then sealed and stored. ⑥ Molding: The SiC gate body material is added into a high-strength gate body mold, vibrated and sealed, and then formed in a multi-layer hot press to form a SiC gate body green blank. ⑦ Sintering: The SiC gate body green blank is sintered at high temperature to obtain the SiC gate body; (3) Preparation of ZrO2-CaO-C lining: ① Prepare the ingredients according to the weight ratio; ② Mixing: Add the lining raw materials to a high-speed mixer, and finally add phenolic resin. Mix evenly and then dry for later use. ③ Molding: Add the mixed lining material into a high-strength lining mold, vibrate to compact and seal, and then mold in a multi-layer hot press to form a ZrO2-CaO-C lining green blank; ④ Sintering: The ZrO2-CaO-C liner is sintered at high temperature to obtain the ZrO2-CaO-C liner; (4) Preparation of erosion-resistant composite coating: The raw materials, including fused silica, silica fume, aluminate cement, and aqueous solution, are mixed evenly according to the weight ratio to obtain an erosion-resistant composite coating. (5) A erosion-resistant composite coating is applied to the ZrO2-CaO-C lining: ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining; ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly; ③ After molding, heat to dry; (6) Assembly: After the ZrO2-CaO liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body. (7) Baking: The sprue of the assembled nanocrystalline alloy strip is baked. (8) Grind the nozzle body contact surface, pressure ring contact surface and nozzle cup contact surface at the bottom of the nozzle.

6. The method for preparing a sprue for nanocrystalline alloy strips according to claim 5, characterized in that: Detailed steps include: (1) Fabricate a high-strength sprue body mold and a high-strength inner lining pressing mold; (2) Fabrication of SiC gate body: ① Prepare the ingredients according to the weight ratio; ② Mixing: Add SiC coarse material, SiC fine material, and cellulose into a mixer; ③ Stirring: Start the mixer and stir for 22-24 minutes to obtain solid SiC board material; ④ Add aqueous solution and stir: Add aqueous solution to the solid SiC board material and continue stirring until the temperature reaches 31°C. The stirring time is 22-24 minutes to obtain SiC board material slurry. ⑤ Add glycerin and stir: Add glycerin to the SiC board material slurry and continue stirring for 5 minutes to obtain the SiC sprue body material, and store it in a sealed container; ⑥ Molding: Add the SiC gate body material into the high-strength gate body mold, vibrate to seal, and mold in a multi-layer hot press. The molding pressure is 62-67 MPa, the hot pressing temperature is 230-260 ℃, and the hot pressing time is 23-25 ​​minutes to form a SiC gate body green blank. ⑦ Sintering: The SiC gate body green blank is sintered at 1540±20 ℃ for 9~10 hours to obtain the SiC gate body; (3) Preparation of ZrO2-CaO-C lining: ① Prepare the ingredients according to the weight ratio; ② Mixing: Add the raw materials for the lining, such as coarse calcium zirconate, fine calcium zirconate, flake graphite, and boron carbide, to a high-speed mixer. Finally, add phenolic resin, mix evenly, and then dry for later use. ③ Molding: Add the mixed lining material into a high-strength lining mold, vibrate to compact and seal, and then mold in a multi-layer hot press. The molding pressure is 115-119 MPa, the hot pressing temperature is 230-260 ℃, and the hot pressing time is 23-25 ​​minutes to form a ZrO2-CaO-C lining green blank. ④ Sintering: The SiC sprue body green blank is sintered at 1540±20℃ for 10 to 12 hours to obtain ZrO2-CaO-C lining; (4) Preparation of erosion-resistant composite coating: The raw materials, including fused silica, silica fume, aluminate cement, and aqueous solution, are mixed evenly according to the weight ratio to obtain an erosion-resistant composite coating. (5) A erosion-resistant composite coating is applied to the ZrO2-CaO-C lining: ①Abrasion-resistant composite coating is added to the ZrO2-CaO-C lining; ② After sealing both ends of the ZrO2-CaO-C liner, place it in a high-speed centrifuge, centrifuge to form the desired shape, and coat it evenly; ③ After molding, heat to 410℃ and dry; (6) Assembly: After the ZrO2-CaO liner is coated with high-temperature adhesive, it is inserted into the inner cavity of the SiC nozzle body. (7) Baking: The assembled sprue of the nanocrystalline alloy strip was placed in a constant temperature drying oven at 220℃ and baked for 8 hours. (8) Grind the nozzle body contact surface, pressure ring contact surface and nozzle cup contact surface at the bottom of the nozzle to make its flatness ≤0.05mm.

7. A method for preparing a sprue for nanocrystalline alloy strips according to any one of claims 5-6, characterized in that: Both the high-strength sprue body mold and the inner lining pressing mold are high-strength metal pressure molds.

8. The application of a sprue obtained by the method according to any one of claims 5-7 in the preparation of nanocrystalline alloy strips.

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