Aluminum alloy for cookware and method for manufacturing the same
Patent Information
- Application Number
- CN202611460908.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-20
- Publication Date
- 2026-10-27
AI Technical Summary
[0003]但是，由于其化学性质活泼，易发生腐蚀，且导热性较差；现有技术中通常采用化学镀等方式在铝合金表面制备Ni-P金属层以提高耐蚀性；
本申请通过在铝合金表面微弧氧化、化学镀，形成特定微弧氧化层、镍硼层，提高界面致密性，降低孔隙率，从而提升导热性、耐腐蚀性能，并抑制有害物质迁移。
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of aluminum alloy coating technology, specifically to an aluminum alloy for cookware and its preparation method. Background Technology
[0002] Aluminum alloys are widely used in cookware and pots due to their low density and good machinability, making them an ideal base material for manufacturing cookware, pressure cookers and other kitchen utensils.
[0003] However, due to its active chemical properties, it is prone to corrosion and has poor thermal conductivity; in the existing technology, chemical plating and other methods are usually used to prepare a Ni-P metal layer on the surface of aluminum alloy to improve corrosion resistance. However, conventional chemical plating layers (such as Ni-P alloys) have a typical cellular structure on their surface, with microscopic defects such as pinholes and voids, resulting in poor density. Corrosive media can easily penetrate into the substrate along these defects, leading to increased migration of toxic elements and posing food safety risks. To improve thermal conductivity, existing technologies add thermally conductive fillers to the chemical plating solution. However, these fillers are mostly simple physical mixtures, which have poor dispersibility in the plating solution, are prone to agglomeration, and have poor stability in the chemical plating solution, limiting the potential for performance improvement.
[0004] In summary, the development of an aluminum alloy for cookware is of great significance in addressing the aforementioned issues. Summary of the Invention
[0005] The purpose of this invention is to provide an aluminum alloy for cookware and a method for preparing the same, so as to solve the problems mentioned in the background art.
[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing an aluminum alloy for cookware pots includes the following steps: Step 1: Pre-treat the aluminum alloy; then add it to the electrolyte for micro-arc oxidation to form a micro-arc oxide layer, thus obtaining aluminum alloy A; Step 2: Add aluminum alloy A to the sensitization solution for sensitization treatment, wash and dry; add it to the activation solution for activation treatment, wash and dry; add it to the reduction solution for reduction treatment, wash and dry to obtain aluminum alloy B; Step 3: Chemically plate aluminum alloy B to form a nickel-boron layer, thus obtaining an aluminum alloy for cookware. In the electroless plating process, the electroless plating solution comprises 18-35 g / L nickel chloride (CAS No. 7718-54-9), 8-10 g / L modified composite powder, 0.4-0.6 g / L sodium borohydride, 50-60 mL / L ethylenediamine, 20-50 mg / L sodium molybdate (CAS No. 7631-95-0), 35-40 g / L sodium hydroxide, and the remainder is deionized water.
[0007] In a more optimized manner, the process parameters for the chemical plating treatment are: temperature of 75~85℃, deposition time of 1~1.5h, and pH of 12.0~13.0.
[0008] A more optimized method for preparing the modified composite powder is as follows: Step 1: Add alumina powder to zirconium nitrate solution, ultrasonically disperse, stir evenly, centrifuge, dry, then calcine at 550~650℃ for 1.5~2.5h, cycle 2~3 times, cool to room temperature to obtain zirconium oxide / alumina composite powder; Step 2: Add zirconium oxide / alumina composite powder and epoxy-modified polysiloxane to an ethanol aqueous solution, react at 70~80℃ for 3~4h, cool to room temperature, filter, wash and dry to obtain epoxy-modified composite powder; Step 3: Under a nitrogen atmosphere, the epoxy-modified composite powder is added to a propylene glycol methyl ether aqueous solution, along with taurine and triethylamine; the reaction is carried out at 60-80℃ for 4-6 hours, followed by cooling, filtration, washing, and drying to obtain the modified composite powder.
[0009] Ideally, the alumina powder in the raw materials of the modified composite powder has a particle size of 0.3~0.5μm.
[0010] In a more optimized manner, the solid-liquid ratio of alumina powder to zirconium nitrate solution in the raw materials of the zirconium oxide / alumina composite powder is 1:(7~9), and the zirconium nitrate solution (CAS No. 13746-89-9) is a 20~30wt% zirconium nitrate aqueous solution; In the raw materials of the epoxy-modified composite powder, the mass ratio of zirconium oxide / alumina composite powder to epoxy-modified polysiloxane is (9~12):(4~7); In the raw materials of the modified composite powder, the mass ratio of epoxy-modified composite powder, taurine, and triethylamine is 10:(0.8~2):(0.02~0.06).
[0011] In a further embodiment, by introducing specific components (modified composite powders) into the electroless plating bath, the oxide layer is synergistically maintained, density and thermal conductivity are improved, corrosion resistance is further enhanced, and the migration of harmful elements is inhibited. Zirconia is used to improve the chemical stability of alumina. Furthermore, this application modifies polysiloxane by grafting macromolecular epoxy groups, utilizing its steric hindrance effect to improve the dispersibility of the filler in the plating bath; simultaneously, the polysiloxane segments reduce the surface energy of the powder surface, helping to inhibit the adhesion of hydrogen bubbles at the deposition interface during the electroless plating reaction, promoting rapid bubble desorption, thereby reducing the porosity of the coating and further improving density; by grafting sulfonic acid groups from taurine, negative ions are formed in the strongly alkaline plating bath, attracting positively charged nickel ions in the plating bath through electrostatic interaction, promoting the deposition of nickel-boron alloys around the filler, and further improving overall performance.
[0012] In a more optimized manner, the electrolyte in the micro-arc oxidation process comprises 6-12 g / L sodium hexametaphosphate (CAS No. 10124-56-8), 10-20 g / L sodium metasilicate nonahydrate, 1-5 g / L sodium hydroxide, and 3-6 g / L hexagonal boron nitride; the hexagonal boron nitride has a sheet diameter of 1-2 μm.
[0013] The optimized process parameters for the micro-arc oxidation are: a frequency of 200~400Hz and a current density of 3~10A / dm³. 2 The electrolysis time is 8~15min, the duty cycle is 10~20%, and the electrolyte temperature is 25~35℃.
[0014] In a further approach, hexagonal boron nitride with a specific flake size is introduced into the micro-arc oxidation layer and dispersed in the electrolyte. The micropores formed during the micro-arc oxidation process have a sealing effect, making the film surface denser, reducing the number and size of pores, thereby improving corrosion resistance and reducing the migration of harmful elements. Boron nitride, as a filler, can also improve thermal conductivity. Simultaneously, hexagonal boron nitride can introduce boron into the micro-arc oxidation layer, the same element found in the subsequent nickel-boron layer, which is beneficial for the uniform growth of the nickel-boron alloy on the surface of the micro-arc oxidation layer, thus enhancing interlayer bonding. It is important to note that by limiting the specific boron nitride flake size, only the pores are partially filled, not completely blocked, providing space for secondary filling in the subsequent nickel-boron layer, further improving density.
[0015] In a more optimized manner, the sensitization treatment uses a 1-2 g / L stannous chloride (CAS No. 7772-99-8) aqueous solution for a sensitization time of 2-5 min; the activation treatment uses a 0.5-0.8 g / L palladium chloride aqueous solution for an activation time of 30-50 s; and the reduction treatment uses a 15-25 g / L sodium hypophosphite (CAS No. 10039-56-2) aqueous solution for a reduction time of 30-50 s.
[0016] More preferably, the aluminum alloy includes one of 3003 aluminum alloy, 5005 aluminum alloy, and 6061 aluminum alloy.
[0017] Compared with the prior art, the beneficial effects achieved by the present invention are: This application improves the interface density and reduces the porosity by forming a specific micro-arc oxidation layer and nickel-boron layer on the surface of aluminum alloy through micro-arc oxidation and chemical plating, thereby enhancing thermal conductivity and corrosion resistance and inhibiting the migration of harmful substances.
[0018] Introducing hexagonal boron nitride with a specific flake size into the micro-arc oxidation layer serves two purposes. First, the hexagonal boron nitride can partially fill the micropores generated by micro-arc oxidation, improving the film density and thermal conductivity while reserving space for subsequent filling. Second, the boron element introduced synergistically forms the same element with the subsequent nickel-boron layer, promoting the uniform growth of the nickel-boron layer, thereby helping to improve the interlayer bonding and coating density.
[0019] A nickel-boron layer is formed using a chemical plating solution with specific components, which, compared to a traditional nickel-phosphorus layer, prevents the migration of harmful elements from cookware and reduces food safety risks. Furthermore, to improve the density and thermal conductivity of the nickel-boron layer, a specially modified composite powder is introduced into the chemical plating solution. This modified composite powder uses alumina powder of a specific particle size as a base, synergistically enhancing interfacial compatibility with the alumina, the main component of the micro-arc oxidation layer.
[0020] However, alumina powder has poor stability in strongly alkaline electroless plating solutions, which significantly inhibits its functional improvement and can also create defects in the coating, becoming channels for penetrating corrosion media and reducing density and corrosion resistance. Therefore, in order to solve the above problems, the proposed solution involves immersing the powder in a zirconium oxide solution and calcining it to form a zirconium oxide / alumina composite powder, thereby improving its chemical stability. Furthermore, by grafting macromolecular silanes and taurine, the dispersibility of the filler in the plating solution is improved, further enhancing the overall performance. Detailed Implementation
[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] It should be noted that the following quantities are by weight, and unless otherwise specified in the following examples: The epoxy-modified polysiloxane is epoxy-based silane LK-636; The alumina powder is CT 3000 SG, d 50 It is 0.5μm; The diameter of the hexagonal boron nitride flake is 1.8 μm; Hexagonal boron nitride is a monolayer crystalline HN with a granule diameter of 5 μm; The alumina powder has a particle size of 8μm, and all other raw materials are commercially available.
[0023] Example 1: A method for preparing an aluminum alloy for cookware pots, comprising the following steps: The preparation method of the modified composite powder is as follows: (1) Alumina powder (particle size of 0.5 μm) is added to 25 wt% zirconium nitrate solution at a solid-liquid ratio of 1:8, and ultrasonically dispersed (ultrasonic power set to 200 W, ultrasonic frequency 40 kHz, ultrasonic time 35 min, stirring for 1.5 min every 10 min), stirred evenly, centrifuged (set speed to 8000 r / min, time to 20 min), dried at 90℃ for 12 h, then calcined at 600℃ for 2 h, cyclicated 3 times, and cooled to room temperature to obtain zirconium oxide / alumina composite powder; (2) (2) Zirconia / alumina composite powder and epoxy-modified polysiloxane were added to 80wt% ethanol aqueous solution at a mass ratio of 10.5:5.5 and reacted at 75℃ for 3.5h. After cooling to room temperature, the powder was filtered, washed and dried to obtain epoxy-modified composite powder. (3) Under nitrogen atmosphere, epoxy-modified composite powder was added to 80wt% propylene glycol methyl ether aqueous solution at a mass ratio of 10:1.4:0.04. Taurine and triethylamine were added. The powder was reacted at 70℃ for 5h and then cooled, filtered, washed and dried to obtain modified composite powder. Step 1: Pre-treat the aluminum alloy (3003 aluminum alloy) (grinding and washing); then add it to the electrolyte for micro-arc oxidation (the electrolyte composition includes 6 g / L sodium hexametaphosphate, 10 g / L sodium metasilicate nonahydrate, 1 g / L sodium hydroxide, and 3 g / L hexagonal boron nitride (sheet diameter 1.8 μm); process parameters are: frequency 200 Hz, current density 3 A / dm³). 2 Electrolysis time was 8 min, duty cycle was 10%, electrolyte temperature was 25℃, a micro-arc oxide layer was formed, and aluminum alloy A was obtained; Step 2: Add aluminum alloy A to a sensitization solution for sensitization treatment (sensitization solution is 1.5 g / L stannous chloride aqueous solution, sensitization time is 3.5 min), wash and dry; add to an activation solution for activation treatment (activation solution is 0.65 g / L palladium chloride aqueous solution, activation time is 40 s), wash and dry; add to a reduction solution for reduction treatment (reduction solution is 20 g / L sodium hypophosphite aqueous solution, reduction time is 40 s), wash and dry to obtain aluminum alloy B; Step 3: Chemically plate aluminum alloy B (the chemical plating solution consists of 18 g / L nickel chloride, 8 g / L modified composite powder, 0.4 g / L sodium borohydride, 50 mL / L ethylenediamine, 20 mg / L sodium molybdate, 35 g / L sodium hydroxide, and the remainder is deionized water; the process parameters are: temperature 75℃, deposition time 1 h, pH 12.0) to form a nickel-boron layer, thus obtaining the aluminum alloy for cookware.
[0024] Example 2: A method for preparing an aluminum alloy for cookware pots, comprising the following steps: The preparation method of the modified composite powder is as follows: (1) Alumina powder (particle size of 0.5 μm) is added to 25 wt% zirconium nitrate solution at a solid-liquid ratio of 1:8, and ultrasonically dispersed (ultrasonic power set to 200 W, ultrasonic frequency 40 kHz, ultrasonic time 35 min, stirring for 1.5 min every 10 min), stirred evenly, centrifuged (set speed to 8000 r / min, time to 20 min), dried at 90℃ for 12 h, then calcined at 600℃ for 2 h, cyclicated 3 times, and cooled to room temperature to obtain zirconium oxide / alumina composite powder; (2) (2) Zirconia / alumina composite powder and epoxy-modified polysiloxane were added to 80wt% ethanol aqueous solution at a mass ratio of 10.5:5.5 and reacted at 75℃ for 3.5h. After cooling to room temperature, the powder was filtered, washed and dried to obtain epoxy-modified composite powder. (3) Under nitrogen atmosphere, epoxy-modified composite powder was added to 80wt% propylene glycol methyl ether aqueous solution at a mass ratio of 10:1.4:0.04. Taurine and triethylamine were added. The powder was reacted at 70℃ for 5h and then cooled, filtered, washed and dried to obtain modified composite powder. Step 1: Pre-treat the aluminum alloy (3003 aluminum alloy) (grinding and washing); then add it to an electrolyte for micro-arc oxidation (the electrolyte composition includes 9 g / L sodium hexametaphosphate, 15 g / L sodium metasilicate nonahydrate, 3 g / L sodium hydroxide, and 4.5 g / L hexagonal boron nitride (sheet diameter 1.8 μm); process parameters are: frequency 300 Hz, current density 6.5 A / dm³). 2 The electrolysis time was 11.5 min, the duty cycle was 15%, and the electrolyte temperature was 30℃, forming a micro-arc oxide layer to obtain aluminum alloy A. Step 2: Add aluminum alloy A to a sensitization solution for sensitization treatment (sensitization solution is 1.5 g / L stannous chloride aqueous solution, sensitization time is 3.5 min), wash and dry; add to an activation solution for activation treatment (activation solution is 0.65 g / L palladium chloride aqueous solution, activation time is 40 s), wash and dry; add to a reduction solution for reduction treatment (reduction solution is 20 g / L sodium hypophosphite aqueous solution, reduction time is 40 s), wash and dry to obtain aluminum alloy B; Step 3: Chemically plate aluminum alloy B (the chemical plating solution consists of 26 g / L nickel chloride, 9 g / L modified composite powder, 0.5 g / L sodium borohydride, 55 mL / L ethylenediamine, 35 mg / L sodium molybdate, 38 g / L sodium hydroxide, and the remainder is deionized water; the process parameters are: temperature 80℃, deposition time 1.2 h, pH 12.5) to form a nickel-boron layer, thus obtaining the aluminum alloy for cookware.
[0025] Example 3: A method for preparing an aluminum alloy for cookware pots, comprising the following steps: The preparation method of the modified composite powder is as follows: (1) Alumina powder (particle size of 0.5 μm) is added to 25 wt% zirconium nitrate solution at a solid-liquid ratio of 1:8, and ultrasonically dispersed (ultrasonic power set to 200 W, ultrasonic frequency 40 kHz, ultrasonic time 35 min, stirring for 1.5 min every 10 min), stirred evenly, centrifuged (set speed to 8000 r / min, time to 20 min), dried at 90℃ for 12 h, then calcined at 600℃ for 2 h, cyclicated 3 times, and cooled to room temperature to obtain zirconium oxide / alumina composite powder; (2) (2) Zirconia / alumina composite powder and epoxy-modified polysiloxane were added to 80wt% ethanol aqueous solution at a mass ratio of 10.5:5.5 and reacted at 75℃ for 3.5h. After cooling to room temperature, the powder was filtered, washed and dried to obtain epoxy-modified composite powder. (3) Under nitrogen atmosphere, epoxy-modified composite powder was added to 80wt% propylene glycol methyl ether aqueous solution at a mass ratio of 10:1.4:0.04. Taurine and triethylamine were added. The powder was reacted at 70℃ for 5h and then cooled, filtered, washed and dried to obtain modified composite powder. Step 1: Pre-treat the aluminum alloy (3003 aluminum alloy) (grinding and washing); then add it to the electrolyte for micro-arc oxidation (the electrolyte composition includes 12g / L sodium hexametaphosphate, 20g / L sodium metasilicate nonahydrate, 5g / L sodium hydroxide, and 6g / L hexagonal boron nitride (sheet diameter 1.8μm); process parameters are: frequency 400Hz, current density 10A / dm³). 2 Electrolysis time was 15 min, duty cycle was 20%, electrolyte temperature was 35℃, a micro-arc oxide layer was formed, and aluminum alloy A was obtained; Step 2: Add aluminum alloy A to a sensitization solution for sensitization treatment (sensitization solution is 1.5 g / L stannous chloride aqueous solution, sensitization time is 3.5 min), wash and dry; add to an activation solution for activation treatment (activation solution is 0.65 g / L palladium chloride aqueous solution, activation time is 40 s), wash and dry; add to a reduction solution for reduction treatment (reduction solution is 20 g / L sodium hypophosphite aqueous solution, reduction time is 40 s), wash and dry to obtain aluminum alloy B; Step 3: Chemically plate aluminum alloy B (the chemical plating solution consists of 35 g / L nickel chloride, 10 g / L modified composite powder, 0.6 g / L sodium borohydride, 60 mL / L ethylenediamine, 50 mg / L sodium molybdate, 40 g / L sodium hydroxide, and the remainder is deionized water; the process parameters are: temperature 85℃, deposition time 1.5 h, pH 13.0) to form a nickel-boron layer, thus obtaining the aluminum alloy for cookware.
[0026] Comparative Example 1: The diameter of the hexagonal boron nitride in the micro-arc oxidation layer is too large, with a diameter of 5 μm; the rest is the same as in Example 2.
[0027] Comparative Example 2: No hexagonal boron nitride was added to the micro-arc oxide layer; the rest was the same as in Example 2.
[0028] Comparative Example 3: The nickel-boron layer was changed to a nickel-phosphorus layer; the rest was the same as in Example 2; the specific differences are as follows: Step 1: Pre-treat the aluminum alloy (3003 aluminum alloy) (grinding and washing); then add it to an electrolyte for micro-arc oxidation (the electrolyte composition includes 9 g / L sodium hexametaphosphate, 15 g / L sodium metasilicate nonahydrate, 3 g / L sodium hydroxide, and 4.5 g / L hexagonal boron nitride (sheet diameter 1.8 μm); process parameters are: frequency 300 Hz, current density 6.5 A / dm³). 2 The electrolysis time was 11.5 min, the duty cycle was 15%, and the electrolyte temperature was 30℃, forming a micro-arc oxide layer to obtain aluminum alloy A. Step 2: Add aluminum alloy A to a sensitization solution for sensitization treatment (sensitization solution is 1.5 g / L stannous chloride aqueous solution, sensitization time is 3.5 min), wash and dry; add to an activation solution for activation treatment (activation solution is 0.65 g / L palladium chloride aqueous solution, activation time is 40 s), wash and dry; add to a reduction solution for reduction treatment (reduction solution is 20 g / L sodium hypophosphite aqueous solution, reduction time is 40 s), wash and dry to obtain aluminum alloy B; Step 3: Chemically plate aluminum alloy B (the chemical plating solution consists of 20 g / L nickel sulfate hexahydrate, 25 g / L sodium hypophosphite, 9 mL / L lactic acid, and the remainder is deionized water; the process parameters are: temperature 90℃, deposition time 1.2 h, pH 4.5) to form a nickel-phosphorus layer, thus obtaining aluminum alloy for cookware.
[0029] Comparative Example 4: In the modified composite powder, the zirconium oxide / alumina composite powder was changed to alumina powder; the rest was the same as in Example 2.
[0030] Comparative Example 5: In the modified composite powder, the alumina powder has an excessively large particle size of 8 μm; the rest is the same as in Example 2.
[0031] Comparative Example 6: The modified composite powder was changed to a zirconium oxide / alumina composite powder; the rest was the same as in Example 2.
[0032] Performance testing: The aluminum alloys for cookware prepared in Examples 1-3 and Comparative Examples 1-6 were tested for corrosion resistance, thermal conductivity and migration rate of harmful metals in sequence: (1) Corrosion resistance test: The test was conducted at pH 7.0 and temperature 35±2℃, referring to the neutral salt spray test (NSS) in "GB-T10125-2021 Artificial Atmosphere Corrosion Test Salt Spray Test", and the test period was 48h; after the experiment, the corrosion resistance was rated according to "GB / T 6461-2002", from good to bad, from 10 to 0; (2) Thermal conductivity: The samples were tested by laser flash method. First, the specific heat capacity and density of the samples were tested. Then, the thermal conductivity of the samples was measured by LFA 467 HyperFlash thermal conductivity meter. Finally, the thermal conductivity at 300℃ was calculated by calculation formula. (3) Hazardous element migration test: The samples were soaked in 4% acetic acid at 80°C for 2 days. After soaking, the samples were taken out, washed, dried and the migration amount of nickel was tested.
[0033] The test results are shown in Table 1.
[0034] Table 1
[0035] Conclusions: The data in Table 1 above show that the aluminum alloy for cookware prepared in this application has high density, resulting in good corrosion resistance, thermal conductivity, and reduced migration of harmful elements. Comparative Example 1 shows that the hexagonal boron nitride flakes in the micro-arc oxidation layer are too large (5 μm), exceeding the porosity of the micro-arc oxidation layer, leading to a decrease in overall performance. Comparative Example 2 shows that the micro-arc oxidation layer lacks boron due to the absence of hexagonal boron nitride, resulting in decreased thermal conductivity. Comparative Example 3 shows that adjusting the nickel-boron layer to a nickel-phosphorus layer, which lacks boron, significantly increases the migration rate of harmful elements compared to the nickel-boron layer, leading to a decrease in overall performance. The data from Example 4 shows that when the modified composite powder was changed from zirconium oxide / alumina composite powder to alumina powder, the lack of zirconium oxide protection resulted in decreased chemical stability and easy dissolution in alkaline electroless plating solutions, which in turn caused defects and reduced overall performance. The data from Comparative Example 5 shows that the alumina powder in the modified composite powder had an excessively large particle size and did not synergize with the boron nitride sheets of a specific size, resulting in decreased density and significantly reduced overall performance. The data from Comparative Example 6 shows that when the modified composite powder was changed to zirconium oxide / alumina composite powder, the lack of macromolecular epoxy-modified polysiloxane and taurine grafting resulted in uneven dispersibility, decreased stability, and a lack of steric hindrance and electrostatic adsorption, leading to a decrease in overall performance.
[0036] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 method for preparing an aluminum alloy for cookware pots, characterized in that: Includes the following steps: Step 1: Pre-treat the aluminum alloy; then add it to the electrolyte for micro-arc oxidation to form a micro-arc oxide layer, thus obtaining aluminum alloy A; Step 2: Add aluminum alloy A to the sensitization solution for sensitization treatment, then wash and dry; Add to the activation solution for activation treatment, then wash and dry; The aluminum alloy B is obtained by adding it to a reducing solution for reduction treatment, washing and drying. Step 3: Chemically plate aluminum alloy B to form a nickel-boron layer, thus obtaining an aluminum alloy for cookware. In the electroless plating process, the electroless plating solution comprises 18-35 g / L nickel chloride, 8-10 g / L modified composite powder, 0.4-0.6 g / L sodium borohydride, 50-60 mL / L ethylenediamine, 20-50 mg / L sodium molybdate, 35-40 g / L sodium hydroxide, and the remainder is deionized water.
2. The method for preparing an aluminum alloy for cookware according to claim 1, characterized in that: The process parameters for the chemical plating treatment are: temperature of 75~85℃, deposition time of 1~1.5h, and pH of 12.0~13.
0.
3. The method for preparing an aluminum alloy for cookware according to claim 1, characterized in that: The method for preparing the modified composite powder is as follows: Step 1: Add alumina powder to zirconium nitrate solution, ultrasonically disperse, stir evenly, centrifuge, dry, then calcine at 550~650℃ for 1.5~2.5h, cycle 2~3 times, cool to room temperature to obtain zirconium oxide / alumina composite powder; Step 2: Add zirconium oxide / alumina composite powder and epoxy-modified polysiloxane to an ethanol aqueous solution, react at 70~80℃ for 3~4h, cool to room temperature, filter, wash and dry to obtain epoxy-modified composite powder; Step 3: Under a nitrogen atmosphere, the epoxy-modified composite powder is added to a propylene glycol methyl ether aqueous solution, along with taurine and triethylamine; the reaction is carried out at 60-80℃ for 4-6 hours, followed by cooling, filtration, washing, and drying to obtain the modified composite powder.
4. The method for preparing an aluminum alloy for cookware according to claim 3, characterized in that: The alumina powder in the raw materials of the modified composite powder has a particle size of 0.3~0.5μm.
5. The method for preparing an aluminum alloy for cookware according to claim 3, characterized in that: In the raw materials of the zirconium oxide / alumina composite powder, the solid-liquid ratio of alumina powder to zirconium nitrate solution is 1:(7~9), and the zirconium nitrate solution is 20~30wt% zirconium nitrate solution; In the raw materials of the epoxy-modified composite powder, the mass ratio of zirconium oxide / alumina composite powder to epoxy-modified polysiloxane is (9~12):(4~7); In the raw materials of the modified composite powder, the mass ratio of epoxy-modified composite powder, taurine, and triethylamine is 10:(0.8~2):(0.02~0.06).
6. The method for preparing an aluminum alloy for cookware according to claim 1, characterized in that: In the micro-arc oxidation, the electrolyte comprises 6-12 g / L sodium hexametaphosphate, 10-20 g / L sodium metasilicate nonahydrate, 1-5 g / L sodium hydroxide, and 3-6 g / L hexagonal boron nitride; the hexagonal boron nitride has a sheet diameter of 1-2 μm.
7. The method for preparing an aluminum alloy for cookware according to claim 6, characterized in that: The process parameters for micro-arc oxidation are: frequency of 200~400Hz, current density of 3~10A / dm³. 2 The electrolysis time is 8~15min, the duty cycle is 10~20%, and the electrolyte temperature is 25~35℃.
8. The method for preparing an aluminum alloy for cookware according to claim 1, characterized in that: In the sensitization treatment, the sensitizing solution is a 1-2 g / L stannous chloride aqueous solution, and the sensitization time is 2-5 min; in the activation treatment, the activation solution is a 0.5-0.8 g / L palladium chloride aqueous solution, and the activation time is 30-50 s; in the reduction treatment, the reducing solution is a 15-25 g / L sodium hypophosphite aqueous solution, and the reduction time is 30-50 s.
9. The method for preparing an aluminum alloy for cookware according to claim 1, characterized in that: The aluminum alloy includes one of 3003 aluminum alloy, 5005 aluminum alloy, and 6061 aluminum alloy.
10. The aluminum alloy for cookware prepared by the method for preparing an aluminum alloy for cookware according to any one of claims 1 to 9.