Cooking apparatus and method of manufacturing a cooking plate for cooking foodstuff

Abstract

The application discloses a cooking equipment and a preparation method of a baking tray for cooking food materials, and belongs to the technical field of cooking equipment. The cooking equipment comprises a base, a heating part, and a baking tray assembly. The heating part is arranged in the base. The baking tray assembly is connected with the base. At least part of the heating part is arranged at the bottom of the baking tray assembly. The heating part is used for heating the baking tray assembly. The baking tray assembly has a cooking unit. The cooking unit is used for cooking food materials. The cooking unit is made of titanium alloy composite. The application solves the technical problems that the baking tray assembly of the existing cooking equipment has poor heat conduction performance, insufficient corrosion resistance, easy peeling of the coating, and difficult guarantee of food safety due to improper material selection.

Description

Technical Field

[0001] This invention relates to kitchenware technology, and more specifically, to a cooking device and a method for preparing a baking pan for cooking food. Background Technology

[0002] Existing cooking equipment, such as griddles, baking pans, rice cookers, and pressure cookers, typically uses stainless steel, aluminum alloy, or non-stick coated metal materials for their baking pan components or inner pots. Stainless steel has poor thermal conductivity, making it prone to localized overheating; while aluminum alloy has good thermal conductivity, it is prone to oxidation and discoloration with prolonged use, and may release metal ions upon contact with acidic foods, affecting food safety; non-stick coatings are easily scratched and peeled during use, affecting not only their non-stick performance but also potentially releasing harmful substances. Furthermore, these traditional materials lack sufficient corrosion resistance and wear resistance under prolonged high-temperature cooking and hot-cold cycling conditions, impacting the lifespan of the cooking equipment and user experience. Therefore, providing a cooking device that possesses excellent thermal conductivity, good corrosion and wear resistance, and ensures food safety has become a pressing technical problem to be solved in this field.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a cooking device and a method for preparing a baking pan for cooking food, so as to at least solve the technical problems of poor thermal conductivity, insufficient corrosion resistance, easy peeling of coating, and difficulty in ensuring food safety caused by improper material selection of baking pan components in existing cooking devices.

[0005] To achieve the above objectives, according to one aspect of the present invention, a cooking device is provided, comprising: a base; a heating element disposed within the base; and a baking pan assembly connected to the base, wherein at least a portion of the heating element is disposed at the bottom of the baking pan assembly, the heating element being used to heat the baking pan assembly, wherein the baking pan assembly has a cooking unit for cooking food, the cooking unit being made of a titanium alloy composite.

[0006] Furthermore, the titanium alloy composite includes at least two of titanium, aluminum, and stainless steel.

[0007] Furthermore, the cooking equipment includes at least one of an electric griddle, a rice cooker, and a pressure cooker.

[0008] Further, the heating section includes: a first straight pipe section; a first inner arc-shaped section, the first straight pipe section being located on one side of the first inner arc-shaped section, one end of the first inner arc-shaped section being connected to one end of the first straight pipe section; a first arc-shaped connecting section, the first arc-shaped connecting section being located at one end of the first straight pipe section, the first arc-shaped connecting section being connected to the other end of the first inner arc-shaped section; a first outer arc-shaped section, the first outer arc-shaped section being located on the other side of the first inner arc-shaped section, the first outer arc-shaped section being spaced apart from the first straight pipe section, the first outer arc-shaped section being connected to the other end of the first arc-shaped connecting section; and a straight pipe connecting section, the straight pipe connecting section being located at the other end of the first straight pipe section, the straight pipe connecting section being spaced apart from the first inner arc-shaped section, the straight pipe connecting section being... One end of the pipe connecting section is connected to the other end of the first outer arc-shaped section; the second outer arc-shaped section is arranged opposite to the first outer arc-shaped section, and one end of the second outer arc-shaped section is connected to the other end of the straight pipe connecting section; the second arc-shaped connecting section is arranged opposite to the first arc-shaped connecting section, and one end of the second arc-shaped connecting section is connected to the other end of the second outer arc-shaped section; the second inner arc-shaped section is arranged opposite to the first inner arc-shaped section, and one end of the second inner arc-shaped section is connected to the other end of the second arc-shaped connecting section; the second straight pipe section is arranged opposite to the first straight pipe section, and one end of the second straight pipe section is connected to the other end of the second inner arc-shaped section.

[0009] According to another aspect of the present invention, a method for preparing a baking pan for cooking food is provided, which is used to prepare the cooking unit in the above-mentioned cooking device. The preparation method includes the following steps: Step S1: Polishing a titanium alloy substrate; Step S2: Sandblasting the polished titanium alloy substrate to form a micro-rough structure on the surface of the titanium alloy substrate; Step S3: Electrolytically treating the sandblasted titanium alloy substrate to form a porous oxide film on the micro-rough structure; Step S4: Physical vapor deposition treatment of the electrolytically treated titanium alloy substrate to obtain a titanium alloy substrate with a surface hardness of HV, and fabricating the titanium alloy substrate with a surface hardness of HV into a baking pan with the target structure.

[0010] Further, the polishing treatment in step S1 is selected from one or more combinations of mechanical polishing, chemical polishing or electrolytic polishing. The polishing pressure of mechanical polishing is 0.2 to 0.5 MPa, and the surface roughness Ra after polishing is not greater than 0.4 μm. The polishing solution of chemical polishing is a mixed solution of hydrofluoric acid, nitric acid and water, the polishing temperature is 20 to 50 degrees Celsius, and the polishing time is 1 to 10 minutes.

[0011] Furthermore, the sandblasting medium used in step S2 is selected from one or more of white fused alumina, brown fused alumina, glass beads, quartz sand or silicon carbide. The particle size of the sandblasting medium is 20 to 200 mesh, the spraying pressure is 0.4 to 0.8 MPa, the spraying angle is 60 to 90 degrees, the spraying distance is 100 to 300 mm, and the surface roughness Ra after sandblasting is 1.5 to 6.0 μm.

[0012] Further, the electrolytic treatment in step S3 is either anodic oxidation or micro-arc oxidation; the electrolyte for anodic oxidation is one or more of sulfuric acid, oxalic acid, or phosphoric acid, the voltage is 20 to 120 V, the current density is 0.5 to 5 A / dm², the electrolyte temperature is 0 to 25 degrees Celsius, and the treatment time is 10 to 60 minutes; the electrolyte for micro-arc oxidation is a weakly alkaline solution containing silicates, phosphates, or aluminates, the voltage is 400 to 600 V, the current density is 5 to 20 A / dm², and the treatment time is 5 to 30 minutes.

[0013] Furthermore, the physical vapor deposition process in step S3 is performed in a vacuum environment.

[0014] Furthermore, the physical vapor deposition (PVD) treatment temperature is 250 to 300 degrees Celsius, and the PVD treatment time is 30 hours.

[0015] In this embodiment of the invention, the cooking unit of the baking pan assembly is made of titanium alloy composite. Utilizing the excellent specific strength, corrosion resistance, and biocompatibility of titanium alloy, the cooking unit is resistant to oxidation and discoloration during long-term use, resists acid and alkali corrosion, and does not release harmful metal ions, ensuring food safety. The titanium alloy composite structure has good thermal conductivity, enabling uniform heating and preventing localized overheating. Simultaneously, the high surface hardness and wear resistance of titanium alloy make it less prone to scratches during frequent use and cleaning, extending the service life of the cooking equipment. The cooking equipment using this invention's structure exhibits stable performance of the baking pan assembly under cooking temperatures of 180 to 230 degrees Celsius and hot and cold cycling conditions. It achieves excellent non-stick performance without the need for an additional non-stick coating, and its simple overall structure makes it easy to clean. It is particularly suitable for kitchen appliances such as griddles, baking pans, rice cookers, and pressure cookers, thus solving the technical problems of poor thermal conductivity, insufficient corrosion resistance, easy coating peeling, and difficulty in ensuring food safety in existing cooking equipment's baking pan assemblies due to improper material selection. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0017] Figure 1A schematic diagram of the structure of a first embodiment of the cooking apparatus according to the present invention is shown;

[0018] Figure 2 A schematic diagram of a second embodiment of the cooking apparatus according to the present invention is shown;

[0019] Figure 3 A schematic diagram of the structure of a heating element in a cooking apparatus according to the present invention is shown.

[0020] The above figures include the following reference numerals:

[0021] 10. Base; 20. Heating unit; 201. First straight pipe section; 202. First arc-shaped section; 203. Second arc-shaped section; 204. Third arc-shaped section; 205. First arc-shaped connecting section; 206. First outer arc-shaped section; 207. Straight pipe connecting section; 208. Second straight pipe section; 209. Second arc-shaped connecting section; 210. Second outer arc-shaped section; 30. Baking tray assembly. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0026] Existing cooking appliances such as griddles, baking pans, rice cookers, and pressure cookers typically use stainless steel, aluminum alloy, or non-stick coated metal materials for their baking pan components or inner pots. These traditional materials all exhibit varying degrees of performance defects after long-term use.

[0027] While stainless steel boasts good corrosion resistance and mechanical strength, its poor thermal conductivity—far lower than materials like aluminum alloys and copper—leads to uneven heat distribution during cooking, easily resulting in localized overheating. This localized overheating not only causes uneven heating of food, affecting cooking results, but can also lead to food burning, producing harmful substances, and increasing cleaning difficulty.

[0028] While aluminum alloys offer excellent thermal conductivity, enabling rapid and uniform heating, their low surface hardness and insufficient wear resistance make them prone to scratches during prolonged use and frequent cleaning. Furthermore, aluminum alloys are susceptible to oxidation under high-temperature cooking conditions, gradually discoloring and turning black, affecting the product's appearance. More importantly, when cooking acidic ingredients such as tomatoes, lemons, or vinegar-based dishes, aluminum ions may leach from the aluminum alloy surface. Long-term intake of aluminum ions poses a potential health risk and compromises food safety.

[0029] Non-stick coatings are typically made of polytetrafluoroethylene (PTFE) or ceramic and are applied to the surface of a metal substrate. While these coatings initially exhibit excellent non-stick properties, they have significant limitations during use: the adhesion between the coating and the substrate is limited, and the coating is prone to scratches, blistering, and peeling under conditions such as scraping with metal spatulas, friction from hard foods, or alternating high and low temperatures. Once the coating is damaged, not only does its non-stick performance decrease significantly, but fragments of the damaged coating may also get into the food. Furthermore, the exposed substrate may face the risk of corrosion or metal ion release, further impacting food safety and the user experience.

[0030] Furthermore, the aforementioned traditional materials exhibit insufficient corrosion resistance and wear resistance under prolonged high-temperature cooking and hot-cold cycling conditions, directly impacting the lifespan of cooking equipment and user experience. Therefore, providing a cooking device that possesses excellent thermal conductivity, good corrosion and wear resistance, and ensures food safety has become a pressing technical challenge in this field.

[0031] Combination Figure 1 and Figure 2 As shown, according to a specific embodiment of this application, a cooking device is provided, including: a base 10; a heating element 20 disposed within the base 10; and a baking pan assembly 30 connected to the base 10. At least a portion of the heating element 20 is disposed at the bottom of the baking pan assembly 30, and the heating element 20 is used to heat the baking pan assembly 30. The baking pan assembly 30 has a cooking unit for cooking food, and the cooking unit is made of titanium alloy composite.

[0032] In this embodiment of the invention, the cooking unit of the baking pan assembly is made of titanium alloy composite. Utilizing the excellent specific strength, corrosion resistance, and biocompatibility of titanium alloy, the cooking unit is resistant to oxidation and discoloration during long-term use, resists acid and alkali corrosion, and does not release harmful metal ions, ensuring food safety. The titanium alloy composite structure has good thermal conductivity, enabling uniform heating and preventing localized overheating. Simultaneously, the high surface hardness and wear resistance of titanium alloy make it less prone to scratches during frequent use and cleaning, extending the service life of the cooking equipment. The cooking equipment using this invention's structure exhibits stable performance of the baking pan assembly under cooking temperatures of 180 to 230 degrees Celsius and hot and cold cycling conditions. It achieves excellent non-stick performance without the need for an additional non-stick coating, and its simple overall structure makes it easy to clean. It is particularly suitable for kitchen appliances such as griddles, baking pans, rice cookers, and pressure cookers, thus solving the technical problems of poor thermal conductivity, insufficient corrosion resistance, easy coating peeling, and difficulty in ensuring food safety in existing cooking equipment's baking pan assemblies due to improper material selection.

[0033] Furthermore, the titanium alloy composite includes at least two of titanium, aluminum, and stainless steel. This gives the cooking unit the excellent corrosion resistance, biocompatibility, and high strength of titanium alloy, the excellent thermal conductivity of aluminum alloy, and the good mechanical strength and processing properties of stainless steel. Thus, in the connection structure between the base 10 and the baking pan assembly 30, when the heating unit 20 heats the baking pan assembly 30, the titanium alloy composite structure can achieve rapid and uniform heat conduction, avoiding localized overheating. At the same time, utilizing the high hardness and corrosion resistance of the titanium alloy surface, the cooking unit is not easily oxidized or discolored, nor is it easily scratched or worn during long-term use and frequent cleaning. Moreover, it does not release harmful metal ions when in contact with acidic foods, ensuring food safety. It achieves good non-stick performance without the need for an additional non-stick coating. The overall structure is simple, the performance is stable, and the service life is long.

[0034] In this embodiment, the cooking equipment includes at least one of an electric griddle, a rice cooker, and a pressure cooker. By setting the cooking unit of the baking pan assembly 30 to be made of titanium alloy composite, the heating part 20 can achieve rapid and uniform heat conduction when heating the baking pan assembly 30 under the connection structure between the base 10 and the baking pan assembly 30, avoiding local overheating. At the same time, the high hardness and corrosion resistance of the titanium alloy surface make the cooking unit less prone to oxidation and discoloration, scratches and wear during long-term use and frequent cleaning. Moreover, it does not release harmful metal ions when in contact with acidic foods, ensuring food safety. It achieves good non-stick effect without the need for an additional non-stick coating. The overall structure is simple, the performance is stable, and the service life is long. Specifically, the cooking unit of the electric griddle is the baking pan, the cooking unit of the rice cooker is the inner pot, and the cooking unit of the pressure cooker is the pot body.

[0035] like Figure 3 The heating unit 20 includes: a first straight pipe section 201; a first inner arc-shaped section, the first straight pipe section 201 being located on one side of the first inner arc-shaped section, one end of the first inner arc-shaped section being connected to one end of the first straight pipe section 201; a first arc-shaped connecting section 205, the first arc-shaped connecting section 205 being located at one end of the first straight pipe section 201, and the first arc-shaped connecting section 205 being connected to the other end of the first inner arc-shaped section; a first outer arc-shaped section 206, the first outer arc-shaped section 206 being located on the other side of the first inner arc-shaped section, the first outer arc-shaped section 206 being spaced apart from the first straight pipe section 201, and the first outer arc-shaped section 206 being connected to the other end of the first arc-shaped connecting section 205; and a straight pipe connecting section 207, the straight pipe connecting section 207 being located at the other end of the first straight pipe section 201, the straight pipe connecting section 207 being spaced apart from the first inner arc-shaped section, and the straight pipe connecting section 207 being... One end of the pipe connecting section 207 is connected to the other end of the first outer ring arc section 206; the second outer ring arc section 210 is arranged opposite to the first outer ring arc section 206, and one end of the second outer ring arc section 210 is connected to the other end of the straight pipe connecting section 207; the second arc connecting section 209 is arranged opposite to the first arc connecting section 205, and one end of the second arc connecting section 209 is connected to the other end of the second outer ring arc section 210; the second inner ring arc section is arranged opposite to the first inner ring arc section, and one end of the second inner ring arc section is connected to the other end of the second arc connecting section 209; the second straight pipe section 208 is arranged opposite to the first straight pipe section 201, and one end of the second straight pipe section 208 is connected to the other end of the second inner ring arc section.

[0036] In this embodiment, the heating unit 20 includes a first straight pipe section 201, a first inner arc-shaped section, a first arc-shaped connecting section 205, a first outer arc-shaped section 206, a straight pipe connecting section 207, a second outer arc-shaped section 210, a second arc-shaped connecting section 209, a second inner arc-shaped section, and a second straight pipe section 208. The first straight pipe section 201 and the second straight pipe section 208 are arranged opposite each other, the first inner arc-shaped section and the second inner arc-shaped section are arranged opposite each other, and the first outer arc-shaped section 206 and the second outer arc-shaped section 210 are arranged opposite each other. Each section is connected by a first... An arc-shaped connecting section 205, a second arc-shaped connecting section 209, and a straight pipe connecting section 207 are connected end to end in sequence to form a continuous heating path with inner and outer double rings. This allows the heating unit 20 to achieve a uniform heat distribution from the inner ring to the outer ring at the bottom of the baking pan assembly 30, avoiding the common problems of excessively high center temperature or insufficient edge heating in single ring heating tubes. This ensures that the cooking unit is heated evenly and the food is cooked in a consistent manner. At the same time, the structure is compact and makes full use of the limited space in the base 10, improving heating efficiency and thermal response speed.

[0037] In one exemplary embodiment, the first inner ring arc segment and the second inner ring arc segment have the same structure. Taking one of them as an example, it includes a first unit arc segment 202, a second unit arc segment 203 and a third unit arc segment 204 connected in sequence. The first unit arc segment 202 and the second unit arc segment 203 are arranged in opposite directions.

[0038] In this embodiment, the first inner ring arc segment and the second inner ring arc segment have the same structure. Taking one of them as an example, it includes a first unit arc segment 202, a second unit arc segment 203 and a third unit arc segment 204 connected in sequence. The first unit arc segment 202 and the second unit arc segment 203 are arranged in opposite directions, so that the heating part 20 forms a reciprocating heating path in the inner ring area, which effectively increases the heat distribution density per unit area of ​​the inner ring. This avoids the problem that the center temperature is too high and the edge temperature is insufficient due to the heat concentration in the inner ring area of ​​the traditional single arc heating tube. At the same time, it cooperates with the inner and outer ring coordinated heating structure formed by the first outer ring arc segment 206 and the second outer ring arc segment 210, so that the bottom of the baking pan assembly 30 can obtain uniform and stable heat input from the inner ring to the outer ring, ensuring the heat uniformity of each area of ​​the cooking unit and significantly improving the cooking effect of the food.

[0039] According to another specific embodiment of this application, a method for preparing a baking pan for cooking food is also provided, which is used to prepare the cooking unit in the above-mentioned cooking equipment. The preparation method includes the following steps:

[0040] Step S1: Polish the titanium alloy substrate;

[0041] In step S1, the titanium alloy substrate is polished. The polishing process is selected from one or more combinations of mechanical polishing, chemical polishing or electrolytic polishing. The purpose is to remove the original oxide scale, processing lines and micro defects on the surface of the titanium alloy substrate, so as to provide a clean, flat and consistent base surface for subsequent processing.

[0042] When using mechanical polishing, the polishing pressure should be controlled between 0.2 and 0.5 MPa. Adjusting the pressure allows for precise control of the material removal rate. Too low a pressure results in insufficient removal efficiency, while too high a pressure may introduce surface stress or cause over-removal. The surface roughness Ra after polishing should not exceed 0.4 μm. This roughness range ensures surface flatness and provides a uniform reference surface for subsequent sandblasting, avoiding uneven roughness distribution after sandblasting due to inconsistent original surface conditions. Mechanical polishing is suitable for relatively regular-shaped parts, such as flat baking pans or cylindrical pots.

[0043] When using chemical polishing, the polishing solution is a mixture of hydrofluoric acid, nitric acid, and water. The corrosive effect of hydrofluoric acid and the oxidizing effect of nitric acid are used to uniformly remove material from the titanium alloy surface through a chemical reaction. The polishing temperature is controlled between 20 and 50 degrees Celsius. Too low a temperature results in a slow reaction rate and low polishing efficiency, while too high a temperature leads to a violent and uncontrollable reaction, potentially causing over-corrosion. The polishing time is controlled between 1 and 10 minutes. By controlling the time, the removal thickness can be precisely adjusted. Too short a time results in insufficient polishing, while too long a time may cause excessive surface corrosion or grain boundary erosion. Chemical polishing is suitable for parts with complex shapes, such as rice cooker inner pots with concave-convex structures or irregular curved surfaces. Its stress-free and non-contact characteristics avoid the dead corners that are difficult to reach with mechanical polishing.

[0044] When electropolishing is used, the titanium alloy substrate is placed in the electrolyte as the anode. The surface material is uniformly removed through electrochemical dissolution, which can obtain a mirror-level surface quality without mechanical stress residue. It is particularly suitable for parts with extremely high requirements for surface smoothness and dimensional accuracy.

[0045] After the above polishing process is completed, the oxide scale on the surface of the titanium alloy substrate is completely removed, the micro-defects are repaired, and the surface roughness meets the predetermined requirements, providing a uniform base surface for subsequent sandblasting and ensuring that the micro-rough structure formed after sandblasting has good uniformity and repeatability.

[0046] Step S2: Sandblast the polished titanium alloy substrate to form a micro-rough structure on the surface of the titanium alloy substrate.

[0047] In step S2, the polished titanium alloy substrate is subjected to sandblasting. The purpose of this sandblasting is to impact the surface of the titanium alloy with high-speed jet abrasive media to form a micro-rough structure, thereby increasing the specific surface area of ​​the substrate, providing physical anchoring points for the oxide film formed by subsequent electrolytic treatment, and further enhancing the mechanical bonding force between the subsequent physical vapor deposition coating and the substrate.

[0048] The blasting media used in sandblasting are selected from one or more of white fused alumina, brown fused alumina, glass beads, quartz sand, or silicon carbide. White fused alumina and brown fused alumina are mainly composed of alumina, possessing high hardness and stable chemical properties, making them suitable for efficient cutting of titanium alloy surfaces to create a sharply defined rough morphology. Glass beads have moderate hardness and form relatively rounded pits upon impact, making them suitable for applications requiring high surface finish. Quartz sand and silicon carbide have extremely high hardness and strong cutting ability, making them suitable for heavy-duty roughening treatments. These media can be used individually or in combination as needed; for example, a coarse-grained media can be used for initial roughening, followed by a fine-grained media for fine adjustment.

[0049] The particle size of the blasting medium ranges from 20 to 200 mesh. Coarse-grained media ranging from 20 to 60 mesh are suitable for applications requiring greater roughness, such as heavy-duty components, and can form deeper micro-pits, providing a stronger mechanical interlocking effect. Fine-grained media ranging from 80 to 200 mesh are suitable for thin-walled components or components with high appearance requirements, and can form a uniform and delicate microstructure, avoiding excessive coarsening that could lead to a decrease in substrate strength or uneven coverage of subsequent coatings.

[0050] The spraying pressure should be controlled between 0.4 and 0.8 MPa. Too low a pressure results in insufficient kinetic energy of the medium, making it difficult to form an effective micro-roughening structure; too high a pressure may lead to over-cutting, or even cause surface damage or stress concentration on the substrate. The spraying angle should be controlled between 60 and 90 degrees. A larger angle results in stronger impact and a more pronounced cutting effect; a smaller angle primarily uses tangential impact, reducing over-cutting of the substrate and making it suitable for applications with lower roughness requirements. The spraying distance should be controlled between 100 and 300 mm. Too close a distance leads to concentrated impact force, easily causing localized over-roughening; too far a distance results in attenuation of the medium's kinetic energy and reduced roughening efficiency.

[0051] After sandblasting, the surface roughness Ra is controlled between 1.5 and 6.0 μm. This roughness range provides sufficient mechanical interlocking area to ensure the adhesion strength of subsequent oxide films and coatings, while avoiding uneven coating coverage or stress concentration at sharp points caused by excessive roughening. The specific roughness can be selected according to the operating conditions of the component: for heavy-duty components such as pressure cooker bodies, a higher roughness value can be selected to enhance adhesion; for thin-walled components or components with high appearance requirements such as rice cooker inner pots, a lower roughness value can be selected to ensure the smoothness of the coating surface.

[0052] After sandblasting, the surface of the titanium alloy substrate transforms from a smooth, polished state into a rough structure with uniform micro-pits and protrusions. This structure not only increases the number of surface active sites, providing an ideal adhesion substrate for subsequent electrolytic processing, but also significantly enhances the interfacial bonding strength between the coating and the substrate through a mechanical locking effect during subsequent physical vapor deposition. To remove any abrasive particles that may remain after sandblasting, high-pressure air purging or ultrasonic cleaning can be performed after sandblasting to ensure surface cleanliness.

[0053] Step S3: Electrolytically treat the sandblasted titanium alloy substrate to form a porous oxide film on the micro-rough structure;

[0054] In step S3, the sandblasted titanium alloy substrate undergoes electrolytic treatment. The purpose of this electrolytic treatment is to generate a dense, uniform, and porous oxide film on the micro-roughened structure formed by sandblasting using an electrochemical method. This oxide film not only serves as an independent protective layer but, more importantly, as a transition or anchoring layer for subsequent physical vapor deposition coatings. It significantly improves the adhesion between the coating and the titanium alloy substrate, while suppressing the interdiffusion of substrate and coating elements under high-temperature conditions and mitigating the difference in thermal expansion coefficients between the substrate and the coating. This effectively solves the technical problem of easy peeling of the coating under thermal cycling conditions.

[0055] Electrolytic treatment can be either anodic oxidation or micro-arc oxidation. The two methods have their own characteristics in terms of mechanism, process parameters and the structure of the oxide film formed, and can be selected according to the specific application scenario.

[0056] When using anodizing, the electrolyte is selected from one or more of sulfuric acid, oxalic acid, or phosphoric acid. Sulfuric acid electrolyte is low-cost and simple to operate, suitable for forming thin, dense oxide films; oxalic acid electrolyte can form oxide films with high hardness and good insulation properties, suitable for applications requiring high wear resistance; phosphoric acid electrolyte can form porous structures with larger pore sizes, which is beneficial for the filling and anchoring of subsequent coating materials. The voltage is controlled between 20 and 120V. The low voltage range of 20 to 60V mainly forms a dense barrier layer, while the high voltage range of 60 to 120V forms a porous layer with regular nanopores. Different voltage ranges can be selected as needed to control the structure and properties of the oxide film. The current density is controlled between 0.5 and 5 A / dm². Too low a current density results in slow oxide film growth, while too high a current density may lead to film ablation or a loose structure. The electrolyte temperature is controlled between 0 and 25 degrees Celsius. Low temperatures help suppress the chemical dissolution of the oxide film, resulting in a dense and uniform film structure; too high a temperature intensifies the reaction, easily leading to a loose or powdery film. The processing time is controlled between 10 and 60 minutes. If the time is too short, the oxide film thickness will be insufficient, making it difficult to serve as an effective transition layer; if the time is too long, the film thickness may increase brittleness or decrease dimensional accuracy. The oxide film formed after anodizing treatment has a thickness of 0.5 to 20 μm. The surface of this film has a nanoscale porous structure, which can provide ideal anchoring points for subsequent physical vapor deposition coatings, allowing the coating material to fill the pores and form a dual bonding mechanism of mechanical interlocking and chemical bonding.

[0057] When using micro-arc oxidation, the electrolyte is a weakly alkaline solution containing silicates, phosphates, or aluminates. Silicate electrolytes are low-cost and fast-forming, suitable for large-scale production; phosphate electrolytes form oxide films with higher hardness and wear resistance; and aluminate electrolytes are suitable for applications requiring high insulation performance. The voltage is controlled at 400 to 600 V, a range much higher than that of anodic oxidation, enabling micro-arc discharge on the titanium alloy surface and in-situ generation of a ceramic film through plasma sintering. The current density is controlled at 5 to 20 A / dm², a high current density that helps maintain a stable micro-arc discharge process and promotes rapid growth of the ceramic layer. The processing time is controlled at 5 to 30 minutes; the relatively short micro-arc oxidation time allows for the formation of a thicker ceramic layer in a shorter time. The oxide film formed after micro-arc oxidation is 10 to 50 μm thick, with a crater-like porous surface and a dense ceramic layer inside, primarily composed of rutile titanium dioxide. This film has high hardness, reaching 500 to 800 HV, and extremely strong adhesion to titanium alloy substrates. It can serve as a hard base layer for physical vapor deposition coatings, providing excellent support under impact loads and heavy-duty conditions.

[0058] Regardless of whether anodic oxidation or micro-arc oxidation is used, the porous oxide film formed by electrolytic treatment forms a composite anchoring substrate with the micro-roughened structure created by sandblasting: the micron-sized pits formed by sandblasting provide macroscopic mechanical locking, while the nano-sized pores formed by electrolysis provide microscopic chemical anchoring. Together, they constitute a multi-scale bonding interface, providing an ideal adhesion basis for subsequent physical vapor deposition coatings. This composite structure allows the coating material to fully fill and anchor in the pores of the oxide film during deposition, significantly improving the bonding strength between the coating and the substrate and effectively solving the technical problem of easy peeling off of the coating under thermal cycling conditions.

[0059] Step S4: Perform physical vapor deposition on the electrolytically treated titanium alloy substrate to obtain a titanium alloy substrate with a surface hardness of 1200 HV, and then fabricate the target structure baking pan from the titanium alloy substrate with a surface hardness of 1200 HV.

[0060] In step S4, the titanium alloy substrate after electrolysis is subjected to physical vapor deposition treatment. The purpose of this physical vapor deposition treatment is to deposit a functional layer on the surface of the oxide film formed by electrolysis through physical vapor deposition technology, so as to endow the titanium alloy substrate with high hardness, high wear resistance and excellent surface properties, and finally obtain a titanium alloy substrate with a surface hardness of 1200HV, and then make the titanium alloy substrate into a baking pan with the target structure.

[0061] Physical vapor deposition (PVD) is performed in a vacuum environment. This vacuum effectively reduces interference from gas molecules during the deposition process, preventing oxidation and contamination of the deposited layer and ensuring its purity and density. The PVD temperature range is 250 to 300 degrees Celsius. This precisely designed narrow temperature window is crucial: below 250 degrees Celsius, the surface mobility of the deposited particles is insufficient, hindering their diffusion and arrangement on the substrate surface. This results in high internal stress, poor density, and insufficient adhesion between the deposited layer and the substrate. Above 300 degrees Celsius, the titanium alloy substrate may undergo phase transformation or surface oxidation and discoloration, affecting its mechanical properties and the product's appearance. Furthermore, excessively high temperatures exacerbate interdiffusion between substrate and deposited elements, forming brittle phases at the interface, which in turn reduces the adhesion and hardness of the deposited layer. Therefore, controlling the temperature within the 250 to 300 degree Celsius range avoids high-temperature discoloration of the titanium alloy substrate while ensuring sufficient migration energy for the deposited particles to form a dense, low-stress deposited layer structure.

[0062] The physical vapor deposition (PVD) process takes 30 hours. This time parameter is coupled with the temperature parameter, jointly determining the thickness, density, and microstructure of the deposited layer. 30 hours is considered a long deposition time, its technical significance being that, under relatively low temperatures of 250 to 300 degrees Celsius, extending the deposition time compensates for insufficient atomic diffusion kinetics. This allows sufficient time for deposited particles to diffuse, migrate, and grow on the substrate surface, resulting in a dense, uniform, and defect-free deposited layer structure. A longer deposition time also facilitates the release of internal stress within the deposited layer, preventing cracking or peeling due to residual stress concentration during subsequent use.

[0063] After the above physical vapor deposition treatment, the surface hardness of the titanium alloy substrate reaches more than 1200 HV, the adhesion of the deposited layer is excellent, and there is no peeling or cracking under cooking temperature of 180 to 230 degrees Celsius and hot and cold cycling conditions. A baking pan with the target structure is made from a titanium alloy substrate with a surface hardness of 1200 HV. This baking pan has the following excellent properties: the high-hardness deposited layer gives the baking pan surface excellent wear resistance, making it less prone to scratches under conditions such as scraping with metal spatulas and friction from hard food, and it can maintain good surface quality even after long-term use; the dense and smooth deposited layer surface gives the baking pan excellent non-stick properties, making it less likely for food to stick and easy to clean; because the physical vapor deposition treatment temperature is controlled within the range of 250 to 300 degrees Celsius, which is far below the significant oxidation temperature of titanium alloy, the overall color of the titanium alloy substrate remains unchanged after treatment, preserving the original metallic texture and aesthetic appearance of titanium alloy; the composite treatment process of sandblasting, electrolysis and physical vapor deposition makes the baking pan stable under cold and hot cycling conditions, without peeling or cracking, and significantly extending its service life.

[0064] Furthermore, the polishing treatment in step S1 is selected from one or more combinations of mechanical polishing, chemical polishing, or electrolytic polishing. The polishing pressure for mechanical polishing is 0.2 to 0.5 MPa, and the surface roughness Ra after polishing is no greater than 0.4 μm. The polishing solution for chemical polishing is a mixed solution of hydrofluoric acid, nitric acid, and water, the polishing temperature is 20 to 50 degrees Celsius, and the polishing time is 1 to 10 minutes. By controlling the polishing pressure, post-polishing roughness, polishing solution ratio, polishing temperature, and polishing time within specific ranges, mechanical polishing, chemical polishing, or electrolytic polishing can be flexibly selected or combined according to the shape and size requirements of the titanium alloy substrate. This effectively removes surface oxide scale and microscopic defects while ensuring the consistency and controllability of the surface condition, providing a uniform and stable base surface for subsequent sandblasting.

[0065] Furthermore, in step S2, the sandblasting medium used is selected from one or more of white fused alumina, brown fused alumina, glass beads, quartz sand, or silicon carbide. The particle size of the sandblasting medium is 20 to 200 mesh, the spraying pressure is 0.4 to 0.8 MPa, the spraying angle is 60 to 90 degrees, the spraying distance is 100 to 300 mm, and the surface roughness Ra after sandblasting is 1.5 to 6.0 μm. By controlling the type, particle size, spraying pressure, spraying angle, spraying distance, and surface roughness after sandblasting within specific ranges, a uniform and controllable micro-rough structure is formed on the surface of the titanium alloy substrate. This structure increases the specific surface area and mechanical interlocking area, providing an ideal adhesion substrate for subsequent electrolytic and physical vapor deposition processes, while avoiding substrate damage or uneven coating coverage caused by excessive roughening.

[0066] Specifically, the electrolytic treatment in step S3 is either anodizing or micro-arc oxidation. For anodizing, the electrolyte is one or more of sulfuric acid, oxalic acid, or phosphoric acid; the voltage is 20 to 120 V; the current density is 0.5 to 5 A / dm²; the electrolyte temperature is 0 to 25 degrees Celsius; and the treatment time is 10 to 60 minutes. For micro-arc oxidation, the electrolyte is a weakly alkaline solution containing silicates, phosphates, or aluminates; the voltage is 400 to 600 V; the current density is 5 to 20 A / dm²; and the treatment time is 5 to 30 minutes. By controlling the type of electrolyte, voltage, current density, electrolyte temperature, and treatment time for anodizing or micro-arc oxidation within specific ranges, the electrolytic treatment can controllably form a porous oxide film with suitable thickness and pore structure on the micro-roughened structure formed by sandblasting. This oxide film, acting as a transition layer, effectively alleviates the difference in thermal expansion coefficients between the titanium alloy substrate and the subsequent physical vapor deposition layer, significantly enhancing the interfacial bonding strength.

[0067] In this embodiment, the physical vapor deposition process in step S4 is performed in a vacuum environment. This effectively avoids interference from gas molecules and contamination from impurities during the deposition process, ensuring that the deposited layer has high purity, high density, and excellent bonding strength, thus laying the technological foundation for achieving a surface hardness of 1200 HV.

[0068] Furthermore, the physical vapor deposition (PVD) process is carried out at a temperature of 250 to 300 degrees Celsius for 30 hours. This avoids oxidation and discoloration of the titanium alloy substrate at high temperatures, provides sufficient surface migration energy for the deposited particles, and, combined with the long deposition process of 30 hours, allows the deposited layer to fully densify and grow under low-temperature conditions, releasing internal stress. This results in a strong bond between the deposited layer and the substrate, achieving a surface hardness of over 1200 HV.

[0069] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0070] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0071] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cooking device, characterized in that, include: Base (10); A heating element (20) is disposed within the base (10); A baking pan assembly (30) is connected to the base (10), and at least a portion of the heating element (20) is disposed at the bottom of the baking pan assembly (30). The heating element (20) is used to heat the baking pan assembly (30). The baking pan assembly (30) has a cooking unit for cooking food, and the cooking unit is made of titanium alloy composite.

2. The cooking apparatus according to claim 1, characterized in that, The titanium alloy composite includes at least two of titanium, aluminum, and stainless steel.

3. The cooking apparatus according to claim 1, characterized in that, The cooking equipment includes at least one of an electric griddle, a rice cooker, and a pressure cooker.

4. The cooking apparatus according to claim 1, characterized in that, The heating element (20) includes: First straight pipe section (201); The first inner ring arc segment, the first straight pipe segment (201) is located on one side of the first inner ring arc segment, and one end of the first inner ring arc segment is connected to one end of the first straight pipe segment (201); The first arc-shaped connecting section (205) is located at one end of the first straight pipe section (201) and is connected to the other end of the first inner arc-shaped section. The first outer arc segment (206) is located on the other side of the first inner arc segment. The first outer arc segment (206) is spaced apart from the first straight pipe segment (201). The first outer arc segment (206) is connected to the other end of the first arc connecting segment (205). A straight pipe connection section (207) is located at the other end of the first straight pipe section (201). The straight pipe connection section (207) is spaced apart from the first inner ring arc section. One end of the straight pipe connection section (207) is connected to the other end of the first outer ring arc section (206). The second outer ring arc segment (210) is arranged opposite to the first outer ring arc segment (206), and one end of the second outer ring arc segment (210) is connected to the other end of the straight pipe connection segment (207); The second arc-shaped connecting segment (209) is arranged opposite to the first arc-shaped connecting segment (205), and one end of the second arc-shaped connecting segment (209) is connected to the other end of the second outer arc-shaped segment (210); The second inner arc segment is arranged opposite to the first inner arc segment, and one end of the second inner arc segment is connected to the other end of the second arc connecting segment (209). The second straight pipe section (208) is arranged opposite to the first straight pipe section (201), and one end of the second straight pipe section (208) is connected to the other end of the second inner ring arc section.

5. A method for preparing a baking pan for cooking ingredients, used to prepare the cooking unit in the cooking apparatus according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: Step S1: Polish the titanium alloy substrate; Step S2: Sandblast the polished titanium alloy substrate to form a micro-rough structure on the surface of the titanium alloy substrate. Step S3: Electrolytically treat the sandblasted titanium alloy substrate to form a porous oxide film on the micro-rough structure; Step S4: Perform physical vapor deposition on the electrolytically treated titanium alloy substrate to obtain a titanium alloy substrate with a surface hardness of 1200 HV, and then fabricate the target structure baking pan from the titanium alloy substrate with a surface hardness of 1200 HV.

6. The preparation method according to claim 5, characterized in that, The polishing process in step S1 is selected from one or more combinations of mechanical polishing, chemical polishing or electrolytic polishing. The polishing pressure of mechanical polishing is 0.2 to 0.5 MPa, and the surface roughness Ra after polishing is not greater than 0.4 μm. The polishing solution of chemical polishing is a mixed solution of hydrofluoric acid, nitric acid and water, the polishing temperature is 20 to 50 degrees Celsius, and the polishing time is 1 to 10 minutes.

7. The preparation method according to claim 5, characterized in that, The sandblasting medium used in step S2 is selected from one or more of white fused alumina, brown fused alumina, glass beads, quartz sand or silicon carbide. The particle size of the sandblasting medium is 20 to 200 mesh, the spraying pressure is 0.4 to 0.8 MPa, the spraying angle is 60 to 90 degrees, the spraying distance is 100 to 300 mm, and the surface roughness Ra after sandblasting is 1.5 to 6.0 μm.

8. The preparation method according to claim 5, characterized in that, The electrolytic treatment in step S3 is either anodic oxidation or micro-arc oxidation. The electrolyte for anodic oxidation is one or more of sulfuric acid, oxalic acid, or phosphoric acid, with a voltage of 20 to 120 V, a current density of 0.5 to 5 A / dm², an electrolyte temperature of 0 to 25 degrees Celsius, and a treatment time of 10 to 60 minutes. The electrolyte for micro-arc oxidation is a weakly alkaline solution containing silicates, phosphates, or aluminates, with a voltage of 400 to 600 V, a current density of 5 to 20 A / dm², and a treatment time of 5 to 30 minutes.

9. The preparation method according to claim 5, characterized in that, The physical vapor deposition process in step S4 is performed in a vacuum environment.

10. The preparation method according to claim 5, characterized in that, The physical vapor deposition process is performed at a temperature of 250 to 300 degrees Celsius for 30 hours.

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