A multi-layered diamond composite structure roll

Abstract

The application relates to the technical field of rolling mills, in particular to a novel multi-layer diamond composite structure rolling mill which comprises a roller body, a plurality of wear-resistant layers arranged on the surface of the roller body and an internal cooling channel. The plurality of wear-resistant layers are made of special alloy materials, can significantly improve the wear resistance of the rolling mill and prolong the service life; the unique internal cooling channel design optimizes the cooling liquid flow path and improves the heat dissipation efficiency, thereby endowing the rolling mill with excellent heat conduction performance and enhancing the stability of the rolling mill in a high-temperature environment. The application can effectively solve the problems of easy wear and poor heat dissipation effect of traditional rolling mills, prolong the service life of the rolling mill to more than 20 years and support repeated processing and utilization. The application can effectively reduce the frequency and cost of shutdown maintenance, is particularly suitable for high-strength rolling processes, improves the production efficiency and product quality stability and has high practicability and economic value.

Description

Technical Field

[0001] This utility model belongs to the field of materials processing and manufacturing technology, specifically the field of metal rolling equipment technology, and particularly relates to a roll with a multi-layer diamond composite structure. Background Technology

[0002] With the development of rolling mill manufacturing technology, various wear-resistant and high thermal conductivity rolling mill rolls have been widely used in industrial production, especially in fields such as food, feed, and chemicals where high material purity and processing precision are required. However, existing rolling mill roll technology still has many problems. Currently, most mainstream rolling mill rolls improve wear resistance by stacking hard alloy layers or spraying tungsten carbide onto their surface. However, these methods not only fail to fundamentally solve the problem of roll wear, but also easily lead to heavy metal contamination due to coating peeling in the food industry, seriously affecting product quality and safety. In addition, traditional processes have insufficient heat dissipation capacity at high temperatures, resulting in heat accumulation during rolling, affecting material forming quality and equipment lifespan.

[0003] Patent application number 202411598172.3 describes a technique for depositing diamond on the surface of a roller. While this technique can theoretically form a diamond wear-resistant layer on the roller surface, inherent limitations in the technology lead to uneven diamond deposition. Even after surface polishing, the uneven diamond distribution and resulting sharp-point effect during high-speed roller operation cannot be resolved, thus damaging the equipment. Furthermore, because the diamond is directly attached to the roller substrate surface, the roller cannot be reused after the diamond wear-resistant layer wears down, failing to effectively reduce resource waste caused by roller scrapping.

[0004] Application number 202310290737.0 proposes a method to improve thermal conductivity and density by preparing a metal coating on the surface of diamond particles and then using alternating layers of diamonds of two different particle sizes, followed by high-temperature short-time sintering and gas pressure infiltration. While this technology effectively improves the thermal conductivity and structural stability of the composite material, its application is primarily geared towards electronic packaging or heat dissipation devices. The composite material prepared by this method is difficult to directly apply to the annular working surface of large rolling mill rolls and lacks consideration for impact resistance, wear uniformity, and repairability under dynamic operating conditions.

[0005] The aforementioned issues indicate that while existing diamond composite material technology has made progress in wear resistance and thermal conductivity, it has not yet been systematically optimized for the specific application of rolling mill rolls. Significant shortcomings remain, particularly in areas such as food safety, continuous operation, reworkability, and overall structural reliability. Therefore, there is an urgent need for a novel design specifically for rolling mill rolls, featuring a multi-diamond composite structure, to achieve a comprehensive improvement in performance, including high wear resistance, efficient heat dissipation, pollution-free operation, repairability, and long service life.

[0006] This invention provides a roll with a multi-layer diamond composite structure. Through the multi-layer diamond composite structure roll design, combined with the superior wear resistance and excellent thermal conductivity of diamond, and using a multi-layer gradient bonding process, it solves the problems of easy peeling of the wear-resistant layer, poor heat dissipation, high risk of contamination, and irreparability in the prior art. It significantly extends the service life of the roll, reduces maintenance costs, improves product quality stability, and meets the stringent requirements of high-cleanliness industries such as food and feed. Summary of the Invention

[0007] The purpose of this invention is to provide a roll with a multi-layer diamond composite structure, which solves the problems of insufficient wear resistance, poor heat dissipation and inability to be reused in the prior art by optimizing its structural composition and manufacturing process.

[0008] By employing an innovative multi-layer diamond composite structure design and a unique heat dissipation structure design, this invention significantly improves the wear resistance, high-temperature resistance, and service life of the rolls, while reducing maintenance costs.

[0009] According to a first aspect of this utility model, a roll with a multi-layer diamond composite structure is provided. The roll includes a roll base and a multi-layer composite structure. The multi-layer composite structure is formed by stacking layers of materials through a specific process to form an integral structure, which covers the outer peripheral surface of the roll base and includes, from the inside out: A cemented carbide transition layer is directly attached to the outer peripheral surface of the roll substrate; A diamond composite wear-resistant layer, wherein the diamond composite wear-resistant layer is disposed on the surface of the cemented carbide transition layer; and A diamond coating layer is disposed on the surface of the diamond composite wear-resistant layer.

[0010] Furthermore, the roll matrix with the multi-layer diamond composite structure is made of one or more materials selected from cast iron, manganese steel, or high-speed steel.

[0011] Furthermore, the cemented carbide transition layer is made of nickel-based alloy, cobalt-based alloy or iron-based alloy, and is uniformly covered on the substrate surface by thermal spraying process. The thickness of the cemented carbide transition layer ranges from 0.8 mm to 1.5 mm.

[0012] In one embodiment of this utility model, the cemented carbide transition layer is made of cemented carbide and tungsten carbide particles, and is uniformly covered on the surface of the substrate by a welding process. The cemented carbide is preferably a nickel-based alloy, wherein the nickel-based alloy accounts for 60% of the total mass of the mixed welding material, and the tungsten carbide particles account for 40%.

[0013] Further, the diamond composite wear-resistant layer is made of diamond micron powder and nickel-based tungsten carbide alloy, and is formed by depositing a mixed spray coating onto the surface of the cemented carbide transition layer through a thermal spraying process. Preferably, the ratio of diamond micron powder to nickel-based tungsten carbide alloy in the mixed spray coating is 25-35% : 65-75% by weight. More preferably, the components of the mixed spray coating include: 25-35% diamond micron powder, 30-40% tungsten carbide, 8-15% nickel, 12-20% cubic boron nitride, 3-8% molybdenum, and 2-6% copper. The thickness of the diamond composite wear-resistant layer ranges from 1.2 mm to 2.0 mm.

[0014] Furthermore, the diamond coating layer is made of diamond nanoparticles, which are formed by depositing the diamond nanoparticles onto the surface of the diamond composite wear-resistant layer using physical vapor deposition technology. The thickness of the diamond coating layer is 100 nm to 300 nm.

[0015] According to another aspect of the present invention, in order to further improve the heat dissipation performance of the roll, the roll with a multi-layer diamond composite structure further includes a microchannel cooling system. The microchannel cooling system is disposed inside the roll substrate and includes multiple cooling channels extending along the axial direction of the roll. The multiple cooling channels are distributed in a ring array within the cross section of the roll substrate.

[0016] Furthermore, the radial positions of the plurality of cooling channels are adjacent to the interface between the cemented carbide transition layer and the roll substrate.

[0017] In one embodiment of this utility model, the microchannel cooling system can also be a three-dimensional mesh microchannel cooling structure. The three-dimensional mesh microchannel cooling structure can be designed as a spiral, mesh, or biomimetic leaf vein-like flow channel network, as long as it can increase the contact area with the working surface of the roll and achieve uniform cooling. No specific limitations are made in this utility model.

[0018] According to a third aspect of the present invention, a rolling mill is also provided, the rolling mill comprising rolls having a multi-layer diamond composite structure as described in the first and second aspects of the present invention.

[0019] Compared with the prior art, the advantages and positive effects of this utility model are as follows: I. A multi-layer diamond composite structure design, combining various material properties and processing techniques, enhances the overall performance of the roll. Specifically, a metallurgical bond is formed between the substrate and the cemented carbide transition layer through thermal spraying or welding, achieving a bond strength exceeding 40 MPa. The presence of the cemented carbide transition layer effectively mitigates the difference in thermal expansion between the substrate and the diamond composite wear-resistant layer, preventing cracking caused by thermal stress.

[0020] II. Multiple hard particles in the diamond composite wear-resistant layer are uniformly distributed within the nickel-based alloy matrix through a thermal spraying process, forming a dense composite structure. This structure not only improves the wear resistance of the rolls but also enhances their impact resistance. Furthermore, the addition of cubic boron nitride further improves stability under high-temperature conditions, enabling it to maintain excellent performance even in high-temperature environments.

[0021] III. The surface diamond coating layer is prepared using physical vapor deposition (PVD) technology, and its thickness and uniformity are strictly controlled. The grain size of the coating layer is 10-20 nanometers, with no obvious defects between grains, thus eliminating the tip effect problem present in traditional diamond deposition technology. The presence of the coating layer also significantly improves the surface finish of the roll, reduces the coefficient of friction, and extends its service life.

[0022] The applications of this invention's rollers are very wide, including in the steel, metallurgical, and construction industries, with particularly prominent applications in the food and feed industries. Because the diamond coating layer on the surface of this invention's rollers is only at the nanometer level, there is no significant risk of heavy metal contamination even after wear. Furthermore, the cubic boron nitride component in the diamond composite wear-resistant layer exhibits excellent oxidation resistance under high-temperature conditions, avoiding the impact of high temperatures on product quality.

[0023] The roller of this invention can be reused after multiple uses by removing the surface coating layer and part of the diamond composite wear-resistant layer, and then recoating the hardened transition layer and diamond composite wear-resistant layer. This design significantly reduces resource waste and aligns with the concept of green environmental protection.

[0024] In summary, this invention solves the problems of insufficient wear resistance, poor heat dissipation, and non-reusability of rolls in existing technologies through a multi-layered composite material design. This technical solution has broad application prospects in multiple industries and demonstrates superior performance advantages in other high-load, high-frequency operating environments. Attached Figure Description

[0025] Figure 1 This is an overall schematic diagram of the roll with a multi-layer diamond composite structure in Example 1; Figure 2 This is a schematic cross-sectional view of the roll with a multi-layer diamond composite structure in Example 1; Figure 3 This is a schematic longitudinal sectional view of the roll with a multi-layer diamond composite structure in Example 1. Figure 4 This is a schematic cross-sectional view of the rolls with multilayer diamond composite structures in Examples 2 and 3; Figure 5 This is a schematic longitudinal sectional view of the roll with a multi-layer diamond composite structure in Example 2. Figure 6 This is a schematic longitudinal sectional view of the roll with a multi-layer diamond composite structure in Example 3. In the figure, 1-roller shaft, 2-roller neck and bushing, 3-roller body substrate, 4-hard alloy transition layer, 5-diamond composite wear-resistant layer, 6-diamond coating layer, 7-microchannel cooling system. Detailed Implementation

[0026] The utility model will now be further described in conjunction with the accompanying drawings and specific embodiments. For the sake of brevity, only the parts relevant to the disclosure are schematically shown in each drawing; they do not represent the actual structure of the product. Furthermore, for the sake of clarity and ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "a" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0027] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0029] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] Example 1 The following is passed Figures 1 to 3 This application demonstrates a roll with a multilayer diamond composite structure.

[0031] See Figure 1 , Figure 1This application discloses a rolling mill roll with a multi-layer diamond composite structure, comprising a roll shaft 1, a roll neck and bushing 2, and a roll body 3. The roll shaft 1 and the roll body 3 are connected by the roll neck and bushing 2. In the actual rolling process, the roll body 3 is the main body of the roll that actually participates in rolling the material, and has a smooth cylindrical or grooved surface. The roll body 3 rotates at high speed around the roll shaft 1, and the roll neck and bushing 2 are installed in bearings, transmitting the rolling force to the mill stand through bearing seats and a pressing device.

[0032] See Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the cross-sectional structure of the roll with the multi-layer diamond composite structure. Figure 3 This is a longitudinal cross-sectional view of the roll with the multi-layer diamond composite structure. As shown in the figure, the roll with the multi-layer diamond composite structure includes a roll substrate 3 and a multi-layer composite structure. The multi-layer composite structure is formed by stacking layers of materials through a specific process to form an integral structure, which covers the outer peripheral surface of the roll substrate. From the inside out, it includes: a cemented carbide transition layer 4, a diamond composite wear-resistant layer 5, and a diamond coating layer 6. The layers are tightly bonded together through specific processes and connection methods, thereby achieving the goal of improving the overall performance and extending the service life of the roll.

[0033] The roll substrate 3, serving as the basic support structure for the entire roll, is made of high-strength metallic materials, preferably one or more of cast iron, manganese steel, or high-speed steel. The outer surface of the roll substrate 3 is machined to create a texture with a roughness between Ra 1.6 and Ra 3.2. This rough surface is formed through a sandblasting process, using alumina abrasive particles with a particle size of 0.5 mm to 1.0 mm, and the blasting pressure is controlled between 0.6 MPa and 0.8 MPa to ensure good mechanical adhesion between the subsequent composite coatings and the roll substrate 3.

[0034] Furthermore, the roll base 3 is provided with journals and bushings 2 for mounting bearings at both ends. The surfaces of the journals and bushings 2 are also heat-treated to achieve a hardness of HRC45 or higher, which can effectively meet the fatigue resistance requirements during long-term operation.

[0035] The cemented carbide transition layer 4 is directly attached to the outer peripheral surface of the roll substrate 3 via a thermal spraying process. The bonding between the cemented carbide transition layer and the roll substrate 3 primarily relies on mechanical interlocking and metallurgical bonding. Nickel-based, cobalt-based, or iron-based alloys are uniformly coated onto the surface of the roll substrate 3 using thermal spraying technology, forming a dense metallurgical bonding layer under high temperature and pressure. The thickness of the cemented carbide transition layer 4 ranges from 0.8 to 1.0 mm, and its main function is to alleviate the difference in thermal expansion coefficients between the roll substrate 3 and the composite diamond wear-resistant layer 5, preventing stress concentration cracking caused by temperature changes. Simultaneously, the chemical composition of the cemented carbide transition layer 4 has good compatibility with the metallic binder phase in the composite diamond wear-resistant layer 5, thereby achieving good interfacial bonding.

[0036] The diamond composite wear-resistant layer 5 is the key technology of this utility model. Its thickness ranges from 1.0 to 1.2 mm, and it is disposed on the outer surface of the cemented carbide transition layer 4. The diamond composite wear-resistant layer 5 is also prepared using a thermal spraying process. Specifically, a mixed spray coating composed of diamond micropowder and nickel-based tungsten carbide alloy is deposited on the surface of the cemented carbide transition layer 4 using a thermal spraying process. In the mixed spray coating, the ratio of diamond micropowder to nickel-based tungsten carbide alloy is 25-30% by weight: 70-75%, and the specific components include: 25% diamond micropowder, 37% tungsten carbide, 8% nickel, 16% cubic boron nitride, 8% molybdenum, and 6% copper.

[0037] By using thermal spraying, the high-hardness particles in the composite diamond wear-resistant layer 5 can be fixed in the coating by a metal binder phase, ensuring the uniformity of the internal structure of the composite diamond wear-resistant layer 5 and forming a stable and dense composite structure. At the same time, it avoids the tip effect caused by excessively large particles, which not only improves the wear resistance of the roll, but also enhances its impact resistance.

[0038] Furthermore, after the spraying is completed, the composite diamond wear-resistant layer 5 needs to be polished to control its surface roughness Ra value below 1.6-3.2μm, so as to ensure the adhesion effect of the subsequent surface coating layer 6.

[0039] like Figure 2 and Figure 3As shown, the diamond coating layer 6 further covers the outer surface of the diamond composite wear-resistant layer 5, located on the outermost side of the roll substrate. The diamond coating layer 6 has a thickness of 100 nm and is made of pure diamond micron powder. Specifically, pure diamond micron powder is deposited on the surface of the composite diamond wear-resistant layer 5 using physical vapor deposition (PVD) technology. After coating, the surface roughness Ra value of the diamond coating layer 6 is controlled below 0.1, and it is tightly bonded to the composite diamond wear-resistant layer 5 through atomic-level bonding, further enhancing the stability of the overall structure. This not only improves the surface hardness of the roll but also enhances its corrosion resistance.

[0040] In practical applications, the roll with a multi-layer diamond composite structure of this invention exhibits excellent performance indicators. Replacing traditional rolls with the roll of this invention extends their service life by at least 15 times, reaching over 20 years, and reduces maintenance frequency by approximately 80%, thereby significantly reducing downtime and maintenance costs.

[0041] Furthermore, when the diamond coating layer 6 and the composite diamond wear-resistant layer 5 wear down, the roll substrate 3 and the cemented carbide transition layer 4 can be reused through secondary processing, thereby reducing resource waste. This invention, through the design and optimization of the multi-layer composite structure and manufacturing process, not only improves the overall performance of the roll but also solves problems such as insufficient wear resistance, poor high-temperature performance, and resource waste in existing technologies, providing a more efficient and reliable solution for related industries.

[0042] Example 2 The following is passed Figures 4 to 5 This application demonstrates another type of roll with a multilayer diamond composite structure.

[0043] See Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the cross-sectional structure of the roll with a multi-layer diamond composite structure described in this embodiment. Figure 5 This is a longitudinal cross-sectional view of the roll with the multi-layer diamond composite structure. As can be seen from the figure, the roll with the multi-layer diamond composite structure has structural features similar to those of Example 1, including a roll substrate 3 and a multi-layer composite structure. The multi-layer composite structure covers the outer peripheral surface of the roll substrate and, from the inside out, includes: a cemented carbide transition layer 4, a diamond composite wear-resistant layer 5, and a diamond coating layer 6. The layers are tightly bonded together through specific processes and connection methods, thereby achieving the goal of improving the overall performance and extending the service life of the roll.

[0044] The significant difference between Example 2 and Example 1 lies in that, to further improve the heat dissipation performance of the roll, the roll with the multi-layer diamond composite structure also includes a microchannel cooling system. The microchannel cooling system 7 is disposed inside the roll substrate 3 and includes multiple cooling channels extending along the roll's axial direction. These cooling channels are arranged in a ring array within the cross-section of the roll substrate 3, with their radial positions adjacent to the interface between the cemented carbide transition layer and the roll substrate, thereby minimizing the possibility of heat transfer into the interior of the roll substrate 3. The diameter of the cooling channels is 5 mm to 10 mm, and the spacing between adjacent channels is 10 mm to 15 mm to ensure efficient flow of the cooling medium within the channels.

[0045] To install the microchannel cooling system 7, cooling channel holes are first machined inside the roll base 3. Then, both ends of the cooling channel holes are sealed with seals to prevent cooling medium leakage. The inlet and outlet of the cooling channel are located at both ends of the roll and connected to an external cooling system via pipes. The cooling medium can be water, oil, or air; the appropriate type and flow rate are selected based on the actual operating conditions, without specific limitations.

[0046] The roll substrate 3, serving as the basic support structure for the entire roll, is made of high-strength metallic material, preferably one or more of cast iron, manganese steel, or high-speed steel. The outer surface of the roll substrate 3 is machined to form a texture with a roughness between Ra 1.6 and Ra 3.2, ensuring good mechanical bonding between the subsequent composite coatings and the roll substrate 3.

[0047] In this embodiment, the cemented carbide transition layer 4 is made of cemented carbide and tungsten carbide particles, and is uniformly covered on the substrate surface by a welding process. The cemented carbide is preferably a nickel-based alloy, accounting for 60% of the total mass of the mixed welding material, while the tungsten carbide particles account for 40%. The thickness of the cemented carbide transition layer 4 is approximately 1.2 mm. Its main function is to alleviate the difference in thermal expansion coefficients between the roll substrate 3 and the composite diamond wear-resistant layer 5, avoiding stress concentration cracking caused by temperature changes. Simultaneously, the chemical composition of the cemented carbide transition layer 4 has good compatibility with the metallic binder phase in the composite diamond wear-resistant layer 5, thereby achieving good interfacial bonding.

[0048] The diamond composite wear-resistant layer 5 is the key technology of this invention. Its thickness ranges from approximately 1.2 mm, and it uniformly covers the outer surface of the cemented carbide transition layer 4. The diamond composite wear-resistant layer 5 is made of diamond micron powder and a nickel-based tungsten carbide alloy. Specifically, it is formed by depositing a mixed spray coating of diamond micron powder and nickel-based tungsten carbide alloy in a weight ratio of 28%:72% onto the outer surface of the cemented carbide transition layer 4 using a thermal spraying process. The specific components of the mixed spray coating include: 28% diamond micron powder, 35% tungsten carbide, 12% nickel, 14% cubic boron nitride, 5% molybdenum, and 6% copper.

[0049] By using thermal spraying, the high-hardness particles in the composite diamond wear-resistant layer 5 can be fixed in the coating by a metal binder phase, ensuring the uniformity of the internal structure of the composite diamond wear-resistant layer 5 and forming a stable and dense composite structure. This not only improves the wear resistance of the roll, but also enhances its impact resistance.

[0050] After the spraying is completed, the composite diamond wear-resistant layer 5 is further polished to control its surface roughness Ra value below 1.5μm, so as to ensure the adhesion effect of the subsequent surface coating layer 6.

[0051] like Figure 4 and Figure 5 As shown, the diamond coating layer 6 further covers the outer surface of the diamond composite wear-resistant layer 5, located on the outermost side of the roll substrate. The diamond coating layer 6 has a thickness of 200 nm and is made of pure diamond micron powder. Specifically, pure diamond micron powder is deposited on the surface of the composite diamond wear-resistant layer 5 using physical vapor deposition (PVD) technology. After coating, the surface roughness Ra value of the diamond coating layer 6 is controlled below 0.1, and it is tightly bonded to the composite diamond wear-resistant layer 5 through atomic-level bonding, further enhancing the stability of the overall structure. This not only improves the surface hardness of the roll but also enhances its corrosion resistance.

[0052] In practical applications, the working principle of this roll is as follows: When the roll operates under high load and high frequency conditions, the roll substrate 3 provides overall mechanical support. The hardened alloy transition layer 4 is tightly connected to the roll substrate 3 through its metallurgical interface, while mitigating the difference in thermal expansion between the two. The various hard particles in the diamond composite wear-resistant layer 5 withstand external wear and impact through their dense composite network structure, exhibiting excellent wear resistance and impact resistance. The surface diamond coating layer 6 further improves the surface finish and lubrication performance of the roll through its uniform and dense grain arrangement, reducing the coefficient of friction and extending its service life. When the diamond coating layer 6 and the composite diamond wear-resistant layer 5 wear down, the roll substrate 3 and the hard alloy transition layer 4 can be reused through secondary processing, thereby reducing resource waste.

[0053] Furthermore, the multi-layer diamond composite structure of this invention provides significant advantages in the food and feed industries. Due to the multi-layer composite diamond structure and the addition of a microchannel cooling system, the roll exhibits excellent heat dissipation performance. Under continuous operating conditions, the surface temperature of the roll remains within a safe range, effectively addressing the impact of high temperatures on product quality. Moreover, because the thickness of the surface metal coating layer 6 is only at the nanometer level, there is no significant risk of heavy metal contamination even after wear, ensuring safety in high-cleanliness industries such as the food and feed industries.

[0054] This invention, through the design of a multi-layered composite structure and the optimization of cooling channels, not only improves the overall performance of the rolls but also solves problems such as insufficient wear resistance, poor high-temperature performance, and resource waste in existing technologies. Replacing traditional rolls with rolls made using this invention extends their service life by at least 15 times, reaching over 20 years, and reduces maintenance frequency by approximately 80%, thereby significantly reducing downtime and maintenance costs. It provides a more efficient and reliable solution for related industries.

[0055] Example 3 The following is passed Figure 4 and Figure 6 This application demonstrates another type of roll with a multilayer diamond composite structure.

[0056] See Figure 4 and Figure 6 , Figure 6 This is a schematic diagram of the cross-sectional structure of the roll with a multi-layer diamond composite structure described in this embodiment. Figure 6 This is a longitudinal cross-sectional view of the roll with the multi-layer diamond composite structure. As can be seen from the figure, the roll with the multi-layer diamond composite structure has structural features similar to those of Example 1, including a roll substrate 3 and a multi-layer composite structure. The multi-layer composite structure covers the outer peripheral surface of the roll substrate and, from the inside out, includes: a cemented carbide transition layer 4, a diamond composite wear-resistant layer 5, and a diamond coating layer 6. The layers are tightly bonded together through specific processes and connection methods, thereby achieving the goal of improving the overall performance and extending the service life of the roll.

[0057] The significant difference between Example 3 and Example 1 lies in that, to further improve the heat dissipation performance of the roll, the roll with a multi-layer diamond composite structure also includes a microchannel cooling system. The microchannel cooling system 7 is disposed inside the roll base 3 and includes a three-dimensional mesh microchannel cooling structure composed of multiple cooling channels. This three-dimensional mesh microchannel cooling structure is connected to the cooling medium inlet and outlet disposed on the roll, and is used to circulate the cooling medium during roll operation to remove the heat generated by the working layer of the roll. The three-dimensional mesh microchannel cooling structure can be designed as a spiral, mesh, or biomimetic leaf vein-like channel network, as long as it can increase the contact area with the working surface of the roll and achieve uniform cooling; no specific limitations are imposed in this invention.

[0058] In this embodiment, as Figure 6 As shown, the three-dimensional mesh microchannel cooling structure is designed as a mesh-like flow channel network, uniformly formed on the inner surface of the roll substrate 3, and adjacent to the interface between the cemented carbide transition layer 4 and the roll substrate 3, to minimize the possibility of heat transfer to the interior of the roll substrate 3. The diameter of the cooling channel is 5 mm to 10 mm, and the spacing between adjacent parallel channels is 10 mm to 15 mm to ensure that the cooling medium can flow efficiently within the channel.

[0059] To install the microchannel cooling system 7, cooling channel holes are first machined inside the roll base 3. Then, both ends of the cooling channel holes are sealed with seals to prevent cooling medium leakage. The inlet and outlet of the cooling channels are located at both ends of the roll and connected to an external cooling medium circulation system via rotary joints. The cooling medium can be water, oil, or air; the appropriate type and flow rate are selected based on the actual operating conditions, without specific limitations.

[0060] The roll substrate 3, serving as the basic support structure for the entire roll, is made of high-strength manganese steel. The outer surface of the roll substrate 3 is machined to form a texture with a roughness between Ra 1.6 and Ra 3.2, ensuring good mechanical bonding between the subsequent composite coatings and the roll substrate 3.

[0061] In this embodiment, the cemented carbide transition layer 4 is made of cemented carbide and tungsten carbide particles, and is uniformly covered on the substrate surface by a welding process. The cemented carbide is preferably a nickel-based alloy, accounting for 60% of the total mass of the mixed welding material, while the tungsten carbide particles account for 40%. The thickness of the cemented carbide transition layer 4 is approximately 1.2 mm. Its main function is to alleviate the difference in thermal expansion coefficients between the roll substrate 3 and the composite diamond wear-resistant layer 5, avoiding stress concentration cracking caused by temperature changes. Simultaneously, the chemical composition of the cemented carbide transition layer 4 has good compatibility with the metallic binder phase in the composite diamond wear-resistant layer 5, thereby achieving good interfacial bonding.

[0062] The diamond composite wear-resistant layer 5 is the key technology of this invention. Its thickness ranges from approximately 1.5 mm, and it uniformly covers the outer surface of the cemented carbide transition layer 4. The diamond composite wear-resistant layer 5 is made of diamond micron powder and a nickel-based tungsten carbide alloy. Specifically, it is formed by depositing a mixed spray coating of diamond micron powder and nickel-based tungsten carbide alloy in a weight ratio of 28%:72% onto the outer surface of the cemented carbide transition layer 4 using a thermal spraying process. The specific components of the mixed spray coating include: 28% diamond micron powder, 35% tungsten carbide, 12% nickel, 14% cubic boron nitride, 5% molybdenum, and 6% copper.

[0063] After the spraying is completed, the composite diamond wear-resistant layer 5 is further polished to control its surface roughness Ra value below 1.0μm, so as to ensure the adhesion effect of the subsequent surface coating layer 6.

[0064] like Figure 4 and Figure 6 As shown, the diamond coating layer 6 further covers the outer surface of the diamond composite wear-resistant layer 5, located on the outermost side of the roll substrate. The diamond coating layer 6 has a thickness of 300 nm and is made of pure diamond micron powder. Specifically, pure diamond micron powder is deposited on the surface of the composite diamond wear-resistant layer 5 using physical vapor deposition (PVD) technology. After coating, the surface roughness Ra value of the diamond coating layer 6 is controlled below 0.08, and it is tightly bonded to the composite diamond wear-resistant layer 5 through atomic-level bonding, further enhancing the stability of the overall structure. This not only improves the surface hardness of the roll but also enhances its corrosion resistance.

[0065] In practical applications, the working principle of this roll is as follows: When the roll operates under high load and high frequency conditions, the roll substrate 3 provides overall mechanical support. The hardened alloy transition layer 4 is tightly connected to the roll substrate 3 through its metallurgical interface, while mitigating the difference in thermal expansion between the two. The various hard particles in the diamond composite wear-resistant layer 5 withstand external wear and impact through their dense composite network structure, exhibiting excellent wear resistance and impact resistance. The surface diamond coating layer 6 further improves the surface finish and lubrication performance of the roll through its uniform and dense grain arrangement, reducing the coefficient of friction and extending its service life. When the diamond coating layer 6 and the composite diamond wear-resistant layer 5 wear down, the roll substrate 3 and the hard alloy transition layer 4 can be reused through secondary processing, thereby reducing resource waste.

[0066] Furthermore, the multi-layer diamond composite structure of this invention provides significant advantages in the food and feed industries. Due to the multi-layer composite diamond structure and the addition of a microchannel cooling system, the roll exhibits excellent heat dissipation performance. Under continuous operating conditions, the surface temperature of the roll remains within a safe range, effectively addressing the impact of high temperatures on product quality. Moreover, because the thickness of the surface metal coating layer 6 is only at the nanometer level, there is no significant risk of heavy metal contamination even after wear, ensuring safety in high-cleanliness industries such as the food and feed industries.

[0067] This invention, through the design of a multi-layered composite structure and the optimization of cooling channels, not only improves the overall performance of the rolls but also solves problems such as insufficient wear resistance, poor high-temperature performance, and resource waste in existing technologies. Replacing traditional rolls with rolls made using this invention extends their service life by at least 15 times, reaching over 20 years, and reduces maintenance frequency by approximately 80%, thereby significantly reducing downtime and maintenance costs. It provides a more efficient and reliable solution for related industries.

[0068] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A roll with a multi-layer diamond composite structure, characterized in that, include: Roll substrate; A multi-layered composite structure; The multi-layer composite structure covers the outer peripheral surface of the roll substrate and includes, from the inside out: A cemented carbide transition layer is directly attached to the outer peripheral surface of the roll substrate; A diamond composite wear-resistant layer, wherein the diamond composite wear-resistant layer is disposed on the surface of the cemented carbide transition layer; and A diamond coating layer is disposed on the surface of the diamond composite wear-resistant layer.

2. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, The roll base is made of one or more materials selected from cast iron, manganese steel or high-speed steel.

3. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, The diamond composite wear-resistant layer is formed by depositing a spray coating onto the surface of the cemented carbide transition layer using a thermal spraying process.

4. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, The diamond composite wear-resistant layer is made of a mixed spray coating composed of diamond micro powder and nickel-based tungsten carbide alloy.

5. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, The diamond coating layer is formed by depositing it on the surface of the diamond composite wear-resistant layer using physical vapor deposition technology.

6. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, The thickness of the diamond coating layer is 100 nm to 300 nm.

7. The roll with a multi-layer diamond composite structure according to claim 1, characterized in that, It also includes a microchannel cooling system, which is disposed inside the roll matrix.

8. The roll with a multi-layer diamond composite structure according to claim 7, characterized in that, The microchannel cooling system includes multiple cooling channels disposed inside the roll substrate and extending along the roll axial direction, wherein the multiple cooling channels are arranged in a ring array within the cross-section of the roll substrate; optionally, the microchannel cooling system includes a three-dimensional mesh cooling structure composed of multiple cooling channels.

9. The roll with a multi-layer diamond composite structure according to claim 7, characterized in that, The radial position of the microchannel cooling system is adjacent to the interface between the cemented carbide transition layer and the roll substrate.

10. A rolling mill, characterized in that, The roll having a multi-layer diamond composite structure according to any one of claims 1 to 9.

Images