Preparation method of metal ultra-thin strip with snowflake-shaped array structure

Abstract

The invention discloses a preparation method of a metal ultra-thin strip with a snowflake-shaped array structure, which belongs to the technical field of preparation of metal ultra-thin strips and comprises the processes of cutting of a metal substrate, heat treatment before rolling, cleaning, roller laser etching, roller cleaning and rolling. According to the preparation method of the metal ultra-thin strip with the snowflake-shaped array structure, the roller with the snowflake-shaped hydrophobic microstructure on the surface is adopted in the metal ultra-thin strip rolling process, so that the rolling interface contact condition and the self-cleaning performance are improved; the snowflake-shaped hydrophobic microstructure on the surface of the roller is beneficial to stable residence and uniform distribution of a rolling lubricant in the microstructure, so that an effective lubricating isolation layer is formed; according to the method, the surface friction resistance and the surface damage risk are reduced, the common surface pocking marks, scratches and roll sticking defects of rolled metal ultra-thin strips are effectively restrained, the surface smoothness and quality consistency of products are remarkably improved, and reliable guarantee is provided for continuous production of high-quality metal ultra-thin strips.

Description

Technical Field

[0001] This invention relates to the field of metal ultrathin strip fabrication technology, and in particular to a method for fabricating a metal ultrathin strip with a snowflake-like array structure. Background Technology

[0002] With the rapid development of the precision machinery and electronics industries, surface structures with specific morphological characteristics have found widespread and in-depth applications in various fields such as aerospace, automotive manufacturing, and high-end equipment. Among them, snowflake-like surface structures are particularly noteworthy. Their unique multi-level fractal characteristics endow materials with excellent superhydrophobic, anti-icing, and drag-reducing properties, which are of significant value in applications with stringent requirements for resisting liquid penetration, icing, or flow resistance. Especially in precision fields such as electronic equipment and sensors, these surfaces play a crucial role in ensuring stable operation and performance improvement of equipment due to their superior functionality.

[0003] Currently, the fabrication of snowflake-like surface structures mainly relies on high-precision techniques such as laser etching, electron beam lithography, and nanoimprint lithography. Although these methods can achieve the desired complex morphologies, they are usually highly dependent on specific prefabricated templates or masks, which not only significantly increases the complexity of the process steps but also drives up production costs and limits processing efficiency, making it difficult to meet the needs of large-scale mass production.

[0004] Against this backdrop, finding efficient and low-cost manufacturing solutions has become crucial. Traditional microforming technologies such as micro-stamping are considered a potential alternative. However, when attempting to directly form highly complex and delicate snowflake-like surfaces, such technologies typically place stringent requirements on extremely thin strips. This not only presents extremely high challenges to the precision control of equipment and molds, resulting in complex operations with low error tolerance, but also long forming cycles. More importantly, these processes tend to manufacture discrete micro-parts, making it difficult to efficiently and over large areas construct highly ordered and structurally consistent snowflake-like surface arrays directly on thin metal strip substrates. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a metal ultrathin strip with a snowflake-shaped array structure, which improves the surface quality of the metal ultrathin strip, increases production efficiency, and overcomes the limitations of existing technology by optimizing the surface structure, thus opening up a new path for the high-quality production of snowflake-shaped arrays.

[0006] To achieve the above objectives, the present invention provides a method for preparing an extremely thin metal strip with a snowflake-like array structure, comprising the following steps: S1. Cut the metal substrate; S2. Place the metal substrate from S1 in an annealing furnace and perform annealing treatment; S3. Clean the annealed metal substrate; S4. Pre-treat the working surface of the rolls used for rolling metal substrates; S5. Etching is performed on the pretreated working surface of the roll obtained in S4. S6. Clean the surface of the etched rolls; S7. Install the cleaned rolls in a twin-roll mill, and pass the cleaned metal substrate from S3 into the twin-roll mill for rolling to obtain an ultra-thin metal strip with a snowflake-like array structure.

[0007] Preferably, the specific operation of S1 is as follows: cut an ordinary ultra-thin metal strip to obtain a metal substrate, and use a cutting device to cut the metal substrate. The thickness of the metal substrate is 0.8-1.2mm and the width is 5-15cm.

[0008] Preferably, in S2, the annealing temperature is 880-920℃, the annealing time is 1-3h, and the furnace is cooled to 25±5℃.

[0009] Preferably, in S3, the material for surface cleaning is alloy 4J36.

[0010] Preferably, the specific operation of S4 is as follows: the roll to be processed is removed from the twin-roll mill and deeply cleaned to remove rolling oil, metal shavings and residues from the surface of the roll.

[0011] Preferably, the specific operation of S5 is as follows: using high-precision laser equipment, controllable laser etching is performed on the pre-treated working surface of the roll. According to the preset micro-geometry, the laser beam is used to perform precise positioning and scanning on the surface of the roll, and the designed micro-geometry is etched out through ablation.

[0012] Preferably, in S5, the preset micro-geometry is a snowflake-shaped array structure, the etching solution is ferric chloride solution, the solution concentration is controlled at 38°Bé-42°Bé, and the nozzle pressure is controlled at 0.4MPa.

[0013] Preferably, in S6, the etched roll is cleaned using selective chemical cleaning to remove molten spatter, oxide layer and residue generated during the etching process. The reagent for selective chemical cleaning is an alkaline degreasing cleaner.

[0014] Preferably, in S7, the rolling parameters are as follows: the first pass reduction is controlled at 20%-30%, the intermediate pass reduction is controlled at 15%-25%, and the final pass reduction is controlled at 10%-15%. After each pass, intermediate annealing is required, which involves heating to 890℃-910℃ under inert gas protection for 0.5h-2h, followed by furnace cooling to 25±5℃.

[0015] Therefore, the present invention employs the above-mentioned method for preparing a thin metal strip with a snowflake-like array structure, which has the following beneficial effects: (1) Laser etching of snowflake-shaped structure has the advantages of high processing precision, strong controllability and significant surface modification effect. Biomimetic snowflake-shaped micro-patterns are etched on the working surface of the roll using high-precision laser equipment. This structure gives the roll surface excellent hydrophobic properties. The roll surface treated in this way can effectively reduce the rolling friction coefficient, improve the uniformity of metal flow, and significantly enhance the roll's anti-adhesion ability. (2) By using rolls with snowflake-shaped hydrophobic microstructures on the surface during the rolling of ultra-thin metal strips, the contact conditions and self-cleaning performance of the rolling interface are improved. The snowflake-shaped hydrophobic microstructures on the surface of the rolls are conducive to the stable residence and uniform distribution of rolling lubricant in the microstructures, forming an effective lubrication isolation layer. Moreover, the unique geometric features of the snowflake pattern promote the directional removal of fine contaminants generated during the rolling process from the surface of the rolls. This dual effect synergistically reduces the interface friction resistance and the risk of surface damage, effectively suppresses the common surface pitting, scratches and roller sticking defects of ultra-thin metal strips, significantly improves the surface finish and quality consistency of the product, and provides a reliable guarantee for the continuous production of high-quality ultra-thin metal strips.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the rolling process in an embodiment of the method for preparing an ultrathin metal strip with a snowflake-shaped array structure according to the present invention.

[0018] Figure Labels 1. Ultra-thin metal strip; 2. Snowflake upper roller; 3. Snowflake lower roller. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] Example 1 like Figure 1 As shown, the present invention provides a method for preparing an extremely thin metal strip with a snowflake-like array structure, comprising the following steps: S1. Cutting the metal substrate: Cut the ordinary metal ultra-thin strip 1 to obtain the metal substrate, and use a shearing device to cut the metal substrate according to the target product specifications to ensure that the width and length tolerances of the metal substrate meet the requirements of the subsequent rolling process.

[0022] S2. Place the metal substrate from S1 in an annealing furnace and anneal it according to the recrystallization temperature curve of the metal substrate; the annealing temperature is 900℃, the annealing time is 2h, and it is cooled to 25℃ in the furnace.

[0023] S3. Clean the annealed metal substrate to thoroughly remove any slight oxide layer, oil, dust, or other surface contaminants that may remain from the annealing process; the surface cleaning material is alloy 4J36.

[0024] S4. Pre-treatment of the working surface of the rolls for rolling metal substrates: The rolls to be treated are removed from the twin-roll mill and thoroughly cleaned to remove rolling oil, metal shavings and other residues from the roll surface. The rolls include the upper snowflake roll 2 and the lower snowflake roll 3. The rolls are made of high-hardness metal material and are suitable for precision laser processing.

[0025] S5. Etching process is performed on the pre-treated working surface of the roll obtained in S4: Using high-precision laser equipment, controllable laser etching process is performed on the pre-treated working surface of the roll. According to the preset micro-geometry, the laser beam is used to perform precise positioning and scanning on the surface of the roll, and the designed micro-geometry is etched out through ablation.

[0026] The preset microstructure is a snowflake-shaped array structure with oil storage and guiding functions. Its width is set at 10 cm. Other parameters will be gradually optimized in small-batch experiments to achieve better adaptation of the friction state and metal flow between the roll and the ultra-thin metal strip 1. The etching solution is ferric chloride solution, with a concentration controlled at 40°Bé and a nozzle pressure controlled at 0.4 MPa. The etching process must be carried out in a controlled environment, i.e., in a closed environment filled with protective gas. Constant temperature control and relative humidity control at 50% are required during processing. The platform must be kept stable during processing to prevent oxidation of the roll surface.

[0027] S6. Clean the surface of the etched rolls: Use selective chemical cleaning to remove molten spatter, oxide layer, and residue generated during the etching process. The reagent for selective chemical cleaning is an alkaline degreasing cleaner. After cleaning, use phase detection to verify the integrity and cleanliness of the etched texture to ensure that it meets rolling requirements.

[0028] S7. Install the cleaned rolls in the twin-roll mill. First, set and debug the mill parameters, then perform low-speed no-load operation and strip threading test to check the running status and roll gap stability of the twin-roll mill. Apply precisely controlled tension to the inlet and outlet coiling devices of the twin-roll mill, start the twin-roll mill, and thread the metal substrate cleaned in S3 into the twin-roll mill for rolling. The rolling parameters are as follows: the first pass reduction is controlled at 25%, the intermediate pass reduction is controlled at 20%, and the final pass reduction is controlled at 15%. After each pass, intermediate annealing is required. The strip is heated to 900°C under inert gas protection for 1 hour and then cooled to 25°C in the furnace to obtain an ultra-thin metal strip 1 with a snowflake array structure.

[0029] Therefore, this invention employs the aforementioned method for preparing ultra-thin metal strips with a snowflake-like array structure. During the rolling process, the use of rolls with snowflake-like hydrophobic microstructures on their surface improves the interfacial contact conditions and self-cleaning performance. The snowflake-like hydrophobic microstructures on the roll surface facilitate the stable retention and uniform distribution of the rolling lubricant within the microstructures, forming an effective lubrication isolation layer. Furthermore, the unique geometric characteristics of the snowflake pattern promote the directional removal of fine contaminants generated during rolling from the roll surface. This dual effect synergistically reduces interfacial frictional resistance and the risk of surface damage, effectively suppressing common defects in rolled ultra-thin metal strips such as surface pitting, scratches, and roll sticking. It significantly improves the surface finish and quality consistency of the product, providing a reliable guarantee for the continuous production of high-quality ultra-thin metal strips.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an ultrathin metal strip with a snowflake-like array structure, characterized in that: Includes the following steps: S1. Cut the metal substrate; S2. Place the metal substrate from S1 in an annealing furnace and perform annealing treatment; S3. Clean the annealed metal substrate; S4. Pre-treat the working surface of the rolls used for rolling metal substrates; S5. Etching is performed on the pretreated working surface of the roll obtained in S4. S6. Clean the surface of the etched rolls; S7. Install the cleaned rolls in a twin-roll mill, and pass the cleaned metal substrate from S3 into the twin-roll mill for rolling to obtain an ultra-thin metal strip with a snowflake-like array structure.

2. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: The specific operation of S1 is as follows: cut ordinary ultra-thin metal strips to obtain metal substrates, and use a cutting device to cut the metal substrates. The thickness of the metal substrates is 0.8-1.2mm and the width is 5-15cm.

3. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: In S2, the annealing temperature is 880-920℃, the annealing time is 1-3h, and the furnace is cooled to 25±5℃.

4. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: In S3, the material used for surface cleaning is alloy 4J36.

5. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: The specific operation of S4 is as follows: the roll to be processed is removed from the twin-roll mill and deeply cleaned to remove rolling oil, metal shavings and residues from the surface of the roll.

6. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: The specific operation of S5 is as follows: using high-precision laser equipment, controllable laser etching is performed on the pre-treated working surface of the roll. According to the preset micro-geometry, the laser beam is used to perform precise positioning and scanning on the surface of the roll, and the designed micro-geometry is etched out through ablation.

7. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 6, characterized in that: In S5, the preset micro-geometry is a snowflake-shaped array structure, the etching solution is ferric chloride solution, the solution concentration is controlled at 38°Bé-42°Bé, and the nozzle pressure is controlled at 0.4MPa.

8. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: In S6, the etched rolls are cleaned using selective chemical cleaning to remove molten spatter, oxide layer and residue generated during the etching process. The reagent for selective chemical cleaning is an alkaline degreasing cleaner.

9. The method for preparing a thin metal strip with a snowflake-like array structure according to claim 1, characterized in that: In S7, the rolling parameters are as follows: the first pass reduction is controlled at 20%-30%, the intermediate pass reduction is controlled at 15%-25%, and the final pass reduction is controlled at 10%-15%. After each pass, intermediate annealing is required, which involves heating to 890℃-910℃ under inert gas protection for 0.5h-2h, followed by furnace cooling to 25±5℃.

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