Anti-bonding cladding formula for aluminum plate thermal forming die fillet and preparation method

Abstract

The invention provides an anti-bonding cladding formula for an aluminum plate thermal forming die fillet and a preparation method, and belongs to the technical field of die surface strengthening. The anti-bonding cladding formula for the fillet of the aluminum plate thermal forming die comprises the following components in percentage by weight: 45-60% of Ni60 alloy powder, 25-35% of TiC ceramic powder, 3-8% of Mo powder, 2-5% of Nb powder and 1-3% of SiC powder, and the sum of the contents of all the components is 100%. After application, the bonding period of the mold is prolonged to 8000-12000 mold times, the abrasion volume is reduced by 85% or above, the use amount of the release agent is reduced by 80%, the production efficiency is improved, the cost is controlled through local cladding design, a high-hardness metallurgical bonding cladding layer is formed, long-acting bonding prevention of the mold fillet is achieved, and the shutdown cleaning frequency is reduced.

Description

Technical Field

[0001] This application relates to the field of mold surface strengthening, and more specifically, to an anti-adhesion cladding formulation and preparation method for the fillet of aluminum sheet thermoforming molds. Background Technology

[0002] Aluminum sheet thermoforming dies are key equipment in automotive lightweight production, and their inserts are typically made of alloy materials with a hardness of HRC50-56. In actual production, the rounded corners of the die are subjected to continuous friction from the aluminum sheet under high temperature and pressure, resulting in irregular aluminum adhesion every 1000 die cycles. This leads to severe scratches on the surface of the parts, and the scratches further exacerbate the accumulation of adhesion, eventually forcing the die to be stopped for cleaning, which seriously affects the production cycle.

[0003] Current technologies primarily rely on manual cleaning of adhesive residue during each shift's downtime, which is not only labor-intensive but also disrupts normal production processes. While some technologies employ DLC coatings or ceramic spraying to improve anti-sticking performance, DLC coatings are expensive and lack sufficient high-temperature resistance (easily failing above 400℃), while traditional ceramic spraying has poor adhesion (≤30MPa) and is prone to detachment under impact. Therefore, developing a high-hardness, high-adhesion, and cost-effective anti-sticking surface treatment technology has become an urgent industry need.

[0004] How to invent an anti-adhesion cladding formula and preparation method for the rounded corners of aluminum sheet thermoforming molds to improve these problems has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings of existing technologies such as frequent adhesion of rounded corners of aluminum sheet thermoforming molds, high cleaning costs, and insufficient coating durability, this invention provides a cladding formula and treatment method. By forming a high-hardness metallurgically bonded cladding layer, long-term anti-adhesion of mold rounded corners is achieved, reducing the number of downtime cleanings.

[0006] On the one hand, the embodiments of this application provide 1. a filler cladding formula for aluminum plate thermoforming mold, which includes, by weight percentage: 45-60% Ni60 alloy powder, 25-35% TiC ceramic powder, 3-8% Mo powder, 2-5% Nb powder, and 1-3% SiC powder, with the total content of each component being 100%.

[0007] In one specific implementation, the TiC ceramic powder has a particle size of 5-50 μm, and the proportion of particles with a particle size of 5-20 μm is ≥60%.

[0008] In one specific embodiment, the Ni60 alloy powder contains 15-18 wt% Cr, ≤5 wt% Fe, and 4-5 wt% Si.

[0009] This application also discloses a mold cladding layer prepared using the above-mentioned formula. The cladding layer has a thickness of 0.2-0.8 mm, a hardness of HRC65-70, and a metallurgical bonding strength with the mold substrate ≥50 MPa. The cladding layer covers an arc-shaped area of ​​the mold's rounded corner R3-R20 mm, with a coverage width of 5-10 mm on each side of the center line of the rounded corner. After application, the mold can be continuously produced for 8000-12000 cycles without significant aluminum adhesion, and the part scratch defect rate is reduced to below 0.1%. In one specific embodiment, the surface roughness Ra of the cladding layer is ≤0.05 μm, and the surface energy is ≤30 mN / m.

[0010] On the other hand, a method for rounding corner cladding of aluminum sheet thermoforming molds includes the following steps: a. Substrate pretreatment: The rounded corners of the mold insert with a hardness of HRC50-56 are sanded with 800-grit sandpaper, ultrasonically cleaned with acetone for 10-15 minutes, and then dried. b. Powder preparation: Mix the powders of each component according to the proportions in claim 1, ball mill for 2-4 hours, and then pass through a 100-mesh sieve; c. Laser cladding: Fiber laser is used with a power of 1800-2200W, a scanning speed of 4-6mm / s, a powder feeding rate of 8-12g / min, and argon as the protective gas with a flow rate of 15-20L / min. d. Post-treatment: After cladding, allow the surface to cool naturally to room temperature and polish with 1000-grit sandpaper.

[0011] In one specific implementation, the laser cladding spot diameter in step c is 2-4 mm, and the overlap rate is 40-50%.

[0012] In one specific implementation, step d is followed by stress-relief annealing: holding at 300-350℃ for 2-3 hours, followed by furnace cooling.

[0013] Beneficial effects: 1. Significantly improved anti-adhesion performance: The surface energy of the cladding layer is ≤30mN / m, combined with high hardness of HRC65-70, which extends the bonding cycle from 1000 cycles to 8000-12000 cycles and reduces the number of cleaning times by more than 90%. 2. Excellent durability: Metallurgical bonding strength ≥50MPa, far exceeding traditional spraying (≤30MPa), wear volume is reduced by 85% compared to the substrate, and mold life is extended by 2-3 times; 3. Increased production efficiency: No need for frequent machine shutdowns for cleaning; with the addition of release agent, the amount used is reduced by 80%, and the production cycle time is increased by 12-15%; Cost controllable: The partial cladding design reduces powder consumption, and the process cost is reduced by more than 40% compared to DLC coating. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a flowchart of the preparation method of the anti-adhesion cladding formula for the fillet of the aluminum plate thermoforming mold provided in the embodiments of this application; Detailed Implementation

[0016] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0019] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0021] This application provides one aspect, and the embodiments of this application provide 1. a filler cladding formula for rounded corners of aluminum plate thermoforming mold, which includes, by weight percentage: 45-60% Ni60 alloy powder, 25-35% TiC ceramic powder, 3-8% Mo powder, 2-5% Nb powder, and 1-3% SiC powder, with the total content of each component being 100%.

[0022] In one specific embodiment, the TiC ceramic powder has a particle size of 5-50 μm, of which the proportion of particles with a particle size of 5-20 μm is ≥60%; the Ni60 alloy powder has a Cr content of 15-18 wt%, an Fe content of ≤5 wt%, and a Si content of 4-5 wt%.

[0023] In this application, the matrix phase Ni60 alloy powder provides good metallurgical bonding and toughness, and its Cr element can improve corrosion resistance; the main reinforcing phase TiC ceramic powder improves hardness through dispersion strengthening and particle strengthening effects, and the 5-50μm particle size distribution can avoid agglomeration and ensure cladding uniformity; the auxiliary reinforcing phases Mo powder and Nb powder improve wear resistance through solid solution strengthening and precipitation strengthening, wherein Nb can refine grains; and the sintering aid SiC powder lowers the cladding temperature and improves the wettability of the ceramic phase.

[0024] This application also discloses a mold cladding layer prepared using the above-mentioned formula. The cladding layer has a thickness of 0.2-0.8 mm, a hardness of HRC65-70, and a metallurgical bonding strength with the mold substrate ≥50 MPa. The cladding layer covers an arc-shaped area of ​​the mold's rounded corner R3-R20 mm, with a coverage width of 5-10 mm on each side of the center line of the rounded corner. After application, the mold can be continuously produced for 8000-12000 cycles without significant aluminum adhesion, and the part scratch defect rate is reduced to below 0.1%. In one specific embodiment, the surface roughness Ra of the cladding layer is ≤0.05 μm, and the surface energy is ≤30 mN / m.

[0025] On the other hand, please see Figure 1 A method for rounding corners of aluminum sheet thermoforming molds includes the following steps: a. Substrate pretreatment: The rounded corners of the mold insert with a hardness of HRC50-56 are sanded with 800-grit sandpaper, ultrasonically cleaned with acetone for 10-15 minutes, and then dried. b. Powder preparation: Mix the powders of each component according to the proportions in claim 1, ball mill for 2-4 hours, and then pass through a 100-mesh sieve; c. Laser cladding: A fiber laser is used with a power of 1800-2200W, a scanning speed of 4-6mm / s, a powder feeding rate of 8-12g / min, and argon as the protective gas with a flow rate of 15-20L / min. The laser cladding spot diameter in step c is 2-4mm, and the overlap rate is 40-50%. d. Post-treatment: After cladding, allow the surface to cool naturally to room temperature and polish with 1000-grit sandpaper; after step d, stress-relief annealing is also included: hold at 300-350℃ for 2-3 hours and cool with the furnace.

[0026] Laser cladding technology achieves metallurgical bonding, and key parameters have been optimized to prevent cracking: a power of 1800-2200W ensures complete powder melting, a scanning speed of 4-6mm / s balances efficiency and coating quality, and argon protection prevents oxidation. Post-treatment annealing eliminates residual stress and improves coating stability. Application is limited to localized cladding of critical areas with mold fillet radius R3-R20mm, ensuring anti-stick properties while reducing material consumption and meeting cost control requirements.

[0027] This invention describes an anti-adhesion cladding formulation and preparation method for rounded corners of aluminum plate thermoforming molds. Ni60 alloy powder serves as the matrix, forming a continuous molten pool under high laser temperature to ensure compatibility between the cladding layer and the mold substrate (e.g., Cr12MoV). TiC ceramic powder is dispersed in the molten pool, forming a hard phase with the Ni matrix. Combined with the solid solution strengthening and grain refinement effects of Mo and Nb, this constructs a high-hardness structure of HRC65-70, resisting aluminum plate friction and wear. SiC powder lowers the cladding temperature, improves the wettability of the ceramic phase, and prevents cladding layer cracking. This achieves metallurgical bonding between the cladding layer and the substrate (bonding strength ≥50MPa), avoiding the "interlayer separation" problem of traditional spraying. Argon protection prevents molten pool oxidation, ensuring the purity of the cladding layer. The high-hardness structure resists surface damage caused by aluminum plate friction, extending the bonding cycle to 8000-12000 cycles, while reducing reliance on release agents (80% reduction in dosage), thus reducing adhesive formation at the source.

[0028] The above descriptions are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. The above descriptions are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A formulation for anti-adhesion cladding of rounded corners in aluminum sheet thermoforming molds, characterized in that, By weight percentage, it includes: 45-60% Ni60 alloy powder, 25-35% TiC ceramic powder, 3-8% Mo powder, 2-5% Nb powder, and 1-3% SiC powder, with the total content of each component being 100%.

2. The cladding formulation according to claim 1, characterized in that, The TiC ceramic powder has a particle size of 5-50 μm, of which 5-20 μm particles account for ≥60%.

3. The cladding formulation according to claim 1, characterized in that, The Ni60 alloy powder contains 15-18 wt% Cr, ≤5 wt% Fe, and 4-5 wt% Si.

4. A mold cladding layer prepared using the formulation according to any one of claims 1-3, characterized in that, The cladding layer has a thickness of 0.2-0.8mm, a hardness of HRC65-70, and a metallurgical bonding strength with the mold substrate of ≥50MPa. The cladding layer covers the arc-shaped area of ​​the mold's rounded corners R3-R20mm, with a coverage width of 5-10mm on each side of the center line of the rounded corner. After application, the mold can be continuously produced for 8000-12000 cycles without obvious aluminum adhesion, and the part scratch defect rate is reduced to below 0.1%.

5. The mold cladding layer according to claim 4, characterized in that, The surface roughness Ra of the cladding layer is ≤0.05μm, and the surface energy is ≤30mN / m.

6. A method for rounding corner cladding treatment of aluminum plate thermoforming mold, characterized in that, Includes the following steps: a. Substrate pretreatment: The rounded corners of the mold insert with a hardness of HRC50-56 are sanded with 800-grit sandpaper, ultrasonically cleaned with acetone for 10-15 minutes, and then dried. b. Powder preparation: Mix the powders of each component according to the proportions in claim 1, ball mill for 2-4 hours, and then pass through a 100-mesh sieve; c. Laser cladding: Fiber laser is used with a power of 1800-2200W, a scanning speed of 4-6mm / s, a powder feeding rate of 8-12g / min, and argon as the protective gas with a flow rate of 15-20L / min. d. Post-treatment: After cladding, allow the surface to cool naturally to room temperature and polish with 1000-grit sandpaper.

7. The processing method according to claim 6, characterized in that, In step c, the laser cladding spot diameter is 2-4 mm, and the overlap rate is 40-50%.

8. The processing method according to claim 6, characterized in that, Step d is followed by stress-relief annealing: holding at 300-350℃ for 2-3 hours, then cooling in the furnace.

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