High-speed 3D printing composite roller process and equipment

Abstract

The invention discloses a high-speed 3D printing composite roller process and equipment, and particularly relates to the technical field of high-speed additive manufacturing molding, the high-speed 3D printing composite roller process comprises the following steps: S1, preparing a metal material; s2, mounting and sealing a core rod; s3, core rod preheating; s4, printing preparation; s5, metal melting and spraying; s6, treatment of a deposition layer; s7, micro-forging strengthening is conducted; s8, performing three-dimensional printing planning; s9, printing layer by layer; s10, monitoring the process; s11, finishing printing and cooling; and S12, the component is taken out. According to the high-speed 3D printing composite roller process and equipment, metal particles or powder are melted in the crucible and then subjected to spray deposition additive manufacturing, the problem that the technology and equipment are complex when liquid metal flow control is used can be solved, the control technology difficulty is simplified, and the production efficiency is improved. And energy consumption of long-time heat preservation of the molten metal in the liquid metal 3D printing process can be reduced, and pollution to the molten metal caused by corrosion of the refractory material ladle lining in the long-time heat preservation process of the molten metal heat preservation ladle can be reduced.

Description

Technical Field

[0001] This invention relates to the field of high-speed additive manufacturing technology, and in particular to a high-speed 3D printing composite roll process and equipment. Background Technology

[0002] Rolls are considered the "mother of steel." In the steel and non-ferrous metals processing industries, rolls are the core components of rolling mills, directly contacting the workpiece. Their performance and quality play a decisive role in the quality of rolled products and production efficiency. Rolls are mainly divided into two types: integral rolls and composite rolls. Composite rolls use different materials for the outer layer and core, manufactured using a centrifugal composite casting process. The two materials are metallurgically bonded. The outer layer of the roll body is made of a highly wear-resistant material, which not only meets the rolling mill's requirements for wear resistance and thermal fatigue resistance, but also ensures the strength and toughness of the core and roll neck. Commonly used materials for the core include gray cast iron, ductile iron, cast steel, and forged steel. The materials for the outer layer and core of composite rolls are mainly selected based on the material being rolled and the specific performance requirements of the mill stand. Commonly used outer layer materials for composite rolls include chilled cast iron, boundless chilled cast iron, ductile iron, high-chromium cast iron, alloy steel, semi-steel, high-chromium steel, high-speed steel, and cemented carbide.

[0003] Traditional roll manufacturing mainly relies on casting and forging processes. Casting involves pouring molten metal into a specific mold and solidifying it. While this method is suitable for large-scale production, it is difficult to precisely control the internal structure and properties of the roll. Because the molten metal shrinks during solidification, defects such as porosity and shrinkage porosity are prone to occur. These defects reduce the strength and toughness of the roll, leading to premature failure during use and affecting the quality of rolled products and production efficiency. Centrifugal casting composite rolls have advantages such as higher molten metal yield, lower stress, and better material controllability. However, when producing high-alloy composite rolls, the centrifugal force causes high-density alloy elements to concentrate on the outer surface, while low-density alloy elements concentrate on the inner surface, resulting in segregation of the working layer material. This leads to uneven structure and composition, affecting the quality of the roll. Furthermore, using ductile iron for the core results in insufficient neck strength and easy roll breakage. When cast steel is used for the core material, a good composite interface cannot be obtained. Therefore, it cannot meet the requirements for composite rolls with high toughness of the core material, and it is also impossible to manufacture composite rolls with forged steel necks.

[0004] Forged rolls are produced by applying forging pressure to a metal billet, causing it to undergo plastic deformation to obtain the desired shape and properties. The forging process can improve the internal structure of the metal and enhance the mechanical properties of the roll. However, it is difficult to manufacture rolls with complex shapes. The forging process requires multiple heating and deformation processes, which can easily lead to coarse metal grains, reducing the roll's wear resistance and fatigue resistance. In addition, the manufacturing cycle of forged rolls is long and the cost is high, making it less economical for small-batch, customized roll manufacturing. Summary of the Invention

[0005] The main objective of this invention is to provide a high-speed 3D printing composite roll process and equipment, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-speed 3D printing process for composite rolls includes the following steps:

[0008] S1. Metal material preparation: Prepare and smelt metal materials according to the composition requirements, make them into 0.05-6mm granules or powders, and load them into the feeder for later use.

[0009] S2. Mandrel installation and sealing: Install the composite roll mandrel (15) on the deposition layer support plate (21), merge the sealing cavity and tighten it, and fill it with inert protective gas after vacuuming;

[0010] S3, mandrel preheating: The composite roll mandrel (15) is moved into the roll mandrel electromagnetic heating induction coil (11) for heating through the Z-axis transmission system, and the mandrel is rotated in the opposite direction through the Y-axis rotation shaft (23) transmission mechanism to ensure uniform heating;

[0011] S4. Printing preparation: Start the X-axis reciprocating movement mechanism (19) to move the inert gas atomizer (7), stirring friction device (9), and high-frequency micro forging device (18) at the bottom of the metal melting crucible (13) to the starting position of the deposition layer tray (21).

[0012] S5. Start the automatic conveyor of metal particles (33) and send the metal particles (33) into the metal melting crucible (13) for heating and melting. The molten metal liquid (14) flows out through the metal liquid guide pipe (8) and is atomized into metal atomized jet (6), which is continuously sprayed and deposited onto the reverse uniformly rotating deposition layer tray (21) and the preheated composite roll mandrel (15) to form a metallurgical bonding interface.

[0013] S6. Deposition layer treatment: During the continuous jet deposition process, the Y-axis rotation axis (23) continues to rotate in the opposite direction at a certain speed. When the jet additive layer (20) sprayed onto the designed thickness of the deposition layer support plate (21) is rotated by the Y-axis rotation axis (23) to the underside of the stirring friction device (9), the stirring friction motor (10) is started. The friction disk is used to rub, squeeze and stir the deposition layer to refine and homogenize the microstructure of the additive material and improve the interlayer bonding strength.

[0014] S7. Micro-forging reinforcement: When the friction stir extrusion layer rotates in the opposite direction to the underside of the high-frequency micro-forging device (18), the micro-forging motor (17) is started, driving the high-frequency micro-forging device (18) to perform high-frequency vibration micro-forging and extrusion on the unsolidified friction stir extrusion layer, further improving the density of the additive layer and the interlayer bonding force; the interlayer bonding strength is increased by more than 30%.

[0015] S8. 3D Printing Planning: The equipment control system performs layer-by-layer slicing of the 3D CAD model, generates CNC code and plans the forming path, enabling the equipment to perform XYZ 3D motion and 3D printing by layer-by-layer stacking.

[0016] S9. Layer-by-layer printing: After the first layer of additive manufacturing is completed, the Z-axis lifting system 26 drives the sprayed additive layer (20) and composite roll mandrel (15) on the deposition layer support plate 21 to move downward layer by layer. Repeat the above operation to eliminate the weak connection defects between the passes and form a good metallurgical bonding interface.

[0017] S10. Process monitoring: During the printing process, the printing process is monitored by an infrared thermometer and a high-speed monitoring camera, and the air pressure monitoring system adjusts the pressure of the inert gas in the sealed cavity.

[0018] S11. Printing End and Cooling: After printing is completed, turn off the relevant power supply. After the 3D printing composite roll cools down, turn off the vacuum pump and inert gas valve to end the 3D printing preparation process.

[0019] S12. Component Removal: Loosen the hinge bolt (4), open the upper sealing cavity (5), lift the metal melting crucible (13), the molten metal guide pipe (8), the inert gas atomizer (7), the stirring friction device (8), and the high-frequency micro forging device (18) on the upper sealing cavity (5) upwards, start the Z-axis lifting system (26) of the vertical jet deposition 3D printing composite roll equipment, lift the Y-axis rotating shaft (23), the deposition layer support plate (21), and the 3D printed composite roll upwards, remove the 3D printed composite roll from the deposition layer support plate (21), and finally obtain the 3D printed composite roll component of the required size and shape.

[0020] Preferably, the metal materials used in the composite roll mandrel (15) include, but are not limited to, 45# steel, low alloy steel, high strength and toughness alloy ductile iron and mandrels processed from waste rolls.

[0021] Preferably, the composite layer material of the 3D printed composite roll includes, but is not limited to, alloy ductile iron, nickel-chromium-molybdenum alloy cast iron, improved nickel-chromium-molybdenum alloy cast iron, high-chromium cast iron, cast steel, mold steel for hot rolling rolls, mold steel for cold rolling rolls, high-chromium cast steel, semi-steel, high-speed steel, particle-reinforced metal matrix composite material, cemented carbide material, and roll chip granules.

[0022] Preferably, the preheating temperature of the mandrel is 700-1300℃, and the spray deposition rate is 10Kg-400Kg / h.

[0023] Preferably, the inert gas atomizer 7 causes 14 drops of molten metal to impact the deposition plate at a high speed of 1-100 m / s during the metal molten spraying process, and at a speed of 10... 3 ~10 7 Rapid solidification at an ultra-high cooling rate of ℃ / s results in ultra-fine grains and fine, uniform equiaxed or non-dendritic structures with an average grain size of 1–100 μm.

[0024] Preferably, during the stirring friction process, the stirring friction device 9 rotates at a speed of 50 to 3000 rpm / min, with an axial pressure of 5 kN to 400 kN and a downward pressure of 0 to 5 mm. The toothed friction disc has 1 to 9 spiral ribs on its plane, with the spiral ribs having a height of 1 to 6 mm on the shoulder plane, a top width of 1 to 3 mm, and an inclination angle of 5° to 15°.

[0025] Preferably, during the micro-forging process, the micro-forging motor 17 drives the high-frequency micro-forging device 18 with a servo motor or a variable frequency speed control motor as the power source to perform high-frequency vibration micro-forging and extrusion on the unsolidified stirring friction extrusion layer. The extrusion frequency is 50 to 3000 Hz and the extrusion pressure is 5 kN to 400 kN.

[0026] Preferably, in the 3D printing planning step, the equipment control system performs layer slicing processing according to the size and accuracy requirements of the 3D CAD model, and the generated CNC code includes XYZ 3D motion path planning, and the thickness of each spray deposition layer is 0.5 to 5 mm.

[0027] Preferably, in the layer-by-layer printing step, when the subsequent layers are stacked in the area to be added, the flow rate of the molten metal 14 is controlled by adjusting the speed at which the metal particles 33 are fed into the molten metal crucible 13, and the printing time for each layer is 10 to 60 minutes, and the temperature fluctuation range during the printing process is controlled within ±5℃.

[0028] Preferably, a high-speed 3D printing composite roll equipment is provided, wherein the equipment uses the high-speed 3D printing composite roll process described in any one of claims 1-9 to prepare the composite roll.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The high-speed 3D printing composite roll process and equipment provided by the present invention uses a metal jet deposition forming process to directly spray molten metal onto a deposition tray and molten metal 14. During the jet forming process, molten metal droplets impact the deposition tray at a high speed of 1 to 100 m / s, causing mechanical breakage on the deposition surface and rapid solidification at an ultra-high cooling rate of 103 to 107 °C / s, forming ultra-fine grains and fine, uniform equiaxed or non-dendritic structures with an average grain size of 1 to 100 μm, which is significantly better than the millimeter-level grains of traditional casting. This can significantly improve the material strength and toughness, and effectively improve the service performance of the working layer.

[0031] Because droplets undergo dynamic redistribution upon impact with the deposition substrate, the element diffusion time within the molten pool is extremely short, preventing solute atoms from diffusing and agglomerating. This results in a more uniform alloy composition, reducing or eliminating segregation and facilitating the formation of metastable phases. The degree of compositional segregation is reduced by more than 80% compared to traditional casting. The droplets compact upon impact with the substrate, achieving a material density of over 99.5%. Defects such as porosity and shrinkage are significantly reduced compared to traditional casting. The excellent fine-grained structure combined with low segregation characteristics results in comprehensive material properties (strength, toughness, corrosion resistance) exceeding those of traditional casting and forging processes by more than 30%. This eliminates the need for casting and forging processes in traditional rolls, reducing energy consumption by more than 30%. It significantly reduces the number of steps in composite roll fabrication, shortens the product production cycle, and improves productivity. It is particularly suitable for short-process, low-cost, high-quality, high-efficiency, and high-performance additive manufacturing of ultrafine equiaxed crystal composite roll components.

[0032] 2. This invention uses metal particles or powder to melt in a crucible and then spray-deposit additive manufacturing, which can reduce the complexity of technology and equipment involved in controlling the flow of liquid metal, simplify the control technology, and reduce the energy consumption of keeping the liquid metal at a constant temperature for a long time during the liquid metal 3D printing process. It also reduces the contamination of the liquid metal by the melting of the refractory lining during the long-term holding of the liquid metal, simplifies the metal 3D printing manufacturing process, significantly reduces energy consumption in production, and has a short process flow, low cost, high flexibility, and high production efficiency.

[0033] 3. This invention can use metal alloy particles and powders of any shape and size, without being limited by particle shape, size and material type. It can also directly use crushed material from roll cuttings, making it widely applicable and easy to mass-produce in industrial applications. It can be produced by roll manufacturers or by specialized manufacturers, resulting in low particle production costs.

[0034] 4. This invention can directly use recycled overspray powder, realizing the value-added utilization of overspray powder in spray forming, reducing material waste, improving material utilization rate, thereby significantly reducing production costs and achieving energy conservation and emission reduction.

[0035] 5. This invention can use high-strength and high-toughness roller core materials inside the roll to realize the 3D printing manufacturing of composite rolls with 45# forged steel and low alloy forged steel roller cores. It can also directly use roller cores processed from waste rolls of various materials to 3D print and remanufacture waste rolls.

[0036] 6. This invention enables the efficient, low-cost, and stable 3D printing and remanufacturing of composite rolls made from various materials, including alloy ductile iron, nickel-chromium-molybdenum alloy cast iron, improved nickel-chromium-molybdenum alloy cast iron, high-chromium cast iron, cast steel, die steel for rolling mills, high-chromium cast steel, semi-steel, high-speed steel, particle-reinforced metal matrix composites, and cemented carbide materials. It allows for precise control of material composition and microstructure based on the working conditions and performance requirements of different parts of the roll, achieving a gradient distribution of materials. High-hardness and high-wear-resistance materials can be used on the roll surface, resulting in a stable and reliable equiaxed grain structure and forged microstructure working layer material. The manufactured composite rolls exhibit excellent toughness, wear resistance, and thermal crack resistance, effectively improving the quality of 3D-printed composite roll products and significantly enhancing the overall performance of the rolls. Their service life is 3-5 times longer than that of composite rolls manufactured using traditional processes.

[0037] 7. This invention reduces raw material costs and improves production efficiency through near-net-shape manufacturing. Traditional casting or forging composite roll manufacturing processes require a large machining allowance, resulting in low material utilization (typically below 60%), significant material waste, and complex and time-consuming processes involving multiple steps such as die forging, heat treatment, and CNC machining, with production cycles lasting from weeks to months. The high-speed 3D printing composite roll process and equipment provided by this invention eliminates the need for mold manufacturing, allowing direct manufacturing based on a 3D model. This reduces production preparation time and processing steps, significantly shortening the roll manufacturing cycle, achieving near-net-shape forming, reducing subsequent cutting operations (saving 20%–50% of material), increasing material utilization to over 90%, reducing material waste, lowering production costs, and meeting the needs of sustainable development.

[0038] 8. The high-speed 3D printing composite roll process and equipment provided by this invention can quickly respond to the market demand for high-performance, personalized, and customized rolls, and can achieve rapid customization, providing high-quality roll products for industries such as steel and non-ferrous metals. This will help improve the quality and production efficiency of rolled products in my country, meet the demand of high-end manufacturing industries for metal materials, and also provide reference and demonstration for the application of additive manufacturing technology in other high-end equipment manufacturing fields.

[0039] 9. The high-speed 3D printing composite roll process and equipment provided by this invention can achieve efficient and high-quality repair, extend the service life of the roll, save energy and reduce emissions, and promote resource conservation and sustainable development.

[0040] 10. The high-speed 3D printing composite roll process and equipment provided by this invention applies additive manufacturing technology to roll manufacturing, which is expected to break through the limitations of traditional roll manufacturing processes and develop high-performance, personalized roll products and processes. This is expected to solve the problems existing in traditional roll manufacturing processes, promote the technological upgrading and industrial transformation of the roll manufacturing industry, and improve the overall level and international competitiveness of my country's roll manufacturing / remanufacturing.

[0041] 11. The high-speed 3D printing composite roll process and equipment provided by this invention have a simple structure, reasonable design, low equipment investment cost, convenient processing, manufacturing and installation, easy operation, high level of intelligence and efficiency, good performance, and high quality of the formed rolls. When using this invention to 3D print / remanufacture rolls, the process is simple and the process flow is short. Compared with the existing high-energy beam 3D printing process, it reduces the process difficulty and cost. The 3D printing production efficiency is as high as 50Kg~400Kg / h, which can meet the needs of 3D printing production of high-end composite rolls with large thickness and heavy weight. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the high-speed 3D printing composite roll equipment of the present invention;

[0043] Figure 2 This is a top view of the main structure of the present invention;

[0044] Figure 3 This is a schematic diagram of the overall process flow of the present invention.

[0045] In the diagram: 1. Bracket, 2. Support sleeve, 3. Lower sealing cavity, 4. Hinged bolt, 5. Upper sealing cavity, 6. Metal atomizing jet, 7. Inert gas atomizer, 8. Metal liquid guide pipe, 9. Friction stirring device, 10. Friction stirring motor, 11. Roll mandrel electromagnetic heating induction coil, 12. Crucible electromagnetic heating induction coil, 13. Metal melting crucible, 14. Metal liquid, 15. Composite roll mandrel, 16. Lifting ring, 17. Micro forging motor, 18. High-frequency micro forging device 19. X-axis reciprocating movement mechanism; 20. Sprayed additive layer; 21. Deposition layer support plate; 22. Rotary bearing; 23. Y-axis rotating shaft; 24. Air pressure regulating valve; 25. Z-axis lifting transmission system; 26. Z-axis lifting system; 27. Transmission sprocket; 28. Y-axis rotating shaft transmission mechanism; 29. ​​Vacuum pump; 30. Piping; 31. Vacuum pump regulating valve; 32. Metal particle storage container; 33. Metal particles; 34. Automatic metal particle conveyor; 35. Particle conveying pipe. Detailed Implementation

[0046] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0047] Example 1: A high-speed 3D printing process for composite rolls includes the following steps:

[0048] S1. According to the required composition of the 3D printed composite roll working layer material, prepare and melt the metal material, adjust and refine it according to the material composition requirements, and after reaching the required composition and temperature, prepare it into 0.05-6mm particles or powder. Load the prepared roll working layer material particles or powder with the required composition into the feeder for later use.

[0049] S2: Mandrel Installation and Sealing: Install the machined 45# steel, low alloy steel composite roll mandrel 15, alloy ductile iron composite roll mandrel 15, or composite roll mandrel 15 processed from scrap rolls onto the deposition layer support plate 21. Combine the upper sealing cavity 5 and the lower sealing cavity 3 and tighten them into a single unit using the hinge bolt 4. Start the vacuum pump 29 and open the vacuum regulating valve 31 to evacuate the sealing cavity. After the vacuum degree reaches 0.5 to 1 atmosphere, close the vacuum regulating valve 31. Open the inert gas valve and fill the sealing cavity with inert protective gas. After the gas pressure reaches 0.5 to 1 atmosphere, close the inert gas valve to protect the metal atomizing jet 6, the composite roll mandrel 15, and the 3D printed bimetallic composite roll from oxidation.

[0050] S3: Mandrel Preheating: Start the Z-axis transmission system of the vertical high-speed 3D printing composite roll equipment. Through the Z-axis lifting transmission system 25 of the high-speed 3D printing composite roll equipment, the Z-axis lifting system 26 rotates, moving the composite roll mandrel 15 installed on the deposition layer support plate 21 upward into the electromagnetic heating induction coil 11 of the roll mandrel. Start the power supply of the electromagnetic heating induction coil to perform electromagnetic induction heating on the mandrel 15. Start the transmission mechanism of the Y-axis rotating shaft 23. Through the transmission sprocket 27, drive the Y-axis rotating shaft 23 and the composite roll mandrel 15 installed on the deposition layer support plate 21 on the Y-axis rotating shaft 23 to rotate in the opposite direction, so that the composite roll mandrel 15 is heated evenly in the electromagnetic induction coil.

[0051] S4: Preparation of 3D printing composite roll: Start the X-axis reciprocating movement mechanism 19 installed on the upper part of the sealing cavity 5 of the vertical high-speed 3D printing composite roll equipment, and move the inert gas atomizer 7 at the bottom of the metal melting crucible 13 installed on the upper sealing cavity 5, the stirring friction device 9 and the high-frequency micro forging device 18 installed on the upper sealing cavity 5 to the starting position of 3D printing on the deposition layer tray 21 on the Y-axis rotation axis 23 respectively;

[0052] S5: Metal Molten Spray Deposition: Start the automatic conveyor of metal particles 33, and precisely feed the metal particles 33 in the metal particle storage container 32 into the metal molten crucible 13 through the particle conveying pipe 35 at the required flow rate. Start the power controller of the crucible electromagnetic heating induction coil 12 to heat the metal particles 33 in the metal molten crucible 13, so that the metal particles 33 melt into molten metal 14 layer by layer from bottom to top. The molten metal 14 flows out through the molten metal 14 guide pipe 8 at the bottom of the metal molten crucible 13, and passes through the metal... The inert gas atomizer 7 below the liquid metal 14 guide pipe 8 atomizes into a metal atomized jet 6, which is continuously sprayed and deposited onto the reverse-rotating uniformly rotating deposition layer support plate 21 and the preheated composite roll mandrel 15. It is combined with the composite roll mandrel 15, which has been preheated to the required composite temperature, to form a metallurgical bonding interface. The radial composite layer thickness of the composite roll is achieved and controlled by adjusting the reciprocating movement distance of the metal melting crucible 13. The flow rate of the liquid metal 14 is controlled by controlling the speed at which the metal particles 33 are fed into the metal melting crucible 13.

[0053] S6: Eliminating metallurgical defects in the deposition layer and refining grains: During continuous jet deposition, the Y-axis rotation 23 continues to rotate in the opposite direction at a certain speed. When the Y-axis rotation 23 rotates the jet additive layer 20, which is sprayed onto the deposition layer support plate 21 of the designed thickness, to the bottom of the stirring friction device 9, the stirring friction motor 10 in the vertical high-speed 3D printing composite roll equipment is started, driving the friction disk under the stirring friction device 9 to rotate. The helical teeth on the friction disk are inserted into the current semi-solid metal atomized jet 6, which is 0.5 to 1.2 times the thickness of the deposition layer. The shoulder of the hollow friction disk is kept pressed against the top of the deposition layer, and the deposition layer is rubbed, squeezed and stirred. Through the continuous movement and rotation of the friction disk in the deposition layer, the material in the deposition layer area undergoes severe plastic deformation, mixing and breaking dendrites, as well as thermoplastic melting and dynamic recrystallization. This achieves the refinement, homogenization and densification of the microstructure of the additive material and improves the interlayer bonding strength of the composite roll additive layer.

[0054] S7: Improve the density and interlayer bonding of the additive layer: When the friction stir extrusion layer rotates in the reverse direction to the underside of the high-frequency micro forging device 18, the micro forging motor 17 is started, driving the high-frequency micro forging device 18 to move up and down, and providing continuous pressure to the high-frequency micro forging device 18, so that the high-frequency micro forging device 18 moves synchronously along the friction forming trajectory, continuously and synchronously applying small pressure to the currently unsolidified friction stir extrusion layer for high-frequency vibration micro forging and extrusion, so that the friction extrusion stirring layer is subjected to plastic deformation, thereby effectively forging and crushing the branch crystals, refining the grains, improving the internal microstructure, effectively eliminating the pores, lack of fusion, and microcrack defects inside the composite roll additive layer, improving the density of the additive layer metal material, and further improving the connection strength of the interlayer interface of the additive pass;

[0055] S8: 3D Motion Printing Composite Roll: The 3D printing control system of the vertical high-speed 3D printing composite roll equipment is activated through the 3D printing composite roll equipment control system. The X-axis reciprocating movement mechanism 19, the Y-axis rotation axis 23 transmission mechanism, and the Z-axis lifting system 26 of the vertical high-speed 3D printing composite roll equipment are processed into layers according to the size and accuracy requirements of the 3D CAD model of the additive manufacturing composite roll component. The 3D CAD model of the composite roll is sliced ​​layer by layer to generate the CNC code required for each layer of 3D printing. The forming path planning and motion trajectory of the spatial 3D motion mechanism of the vertical high-speed 3D printing composite roll equipment are set, so that the vertical high-speed 3D printing composite roll equipment performs XYZ 3D motion to print the composite roll.

[0056] S9: After the first layer of additive manufacturing is completed, the 3D printing control system will activate the Z-axis lifting transmission system 25, causing the Z-axis lifting system 26 to drive the sprayed additive layer 20 and composite roll mandrel 15 on the deposition layer support plate 21 above the Y-axis rotation axis 23 to move downwards layer by layer at a uniform speed. The downward movement size each time is based on the thickness of each sprayed deposition layer. Subsequent layers are then stacked in the additive manufacturing area. The above operation is repeated along the same path and additive spacing. The molten metal 14 in the metal melting crucible 13 is sprayed onto the deposition layer support plate 21 and the molten metal 14 in the shape of a metal atomized jet 6 through the inert gas atomizer 7 below the molten metal 14 guide pipe 8, with a thickness of 0.5-5 mm. The helical teeth on the friction disk below the stirring friction mechanism are inserted into the unstirred friction area between the current deposition layer and the previous additive manufacturing layer. Under the action of upsetting pressure and plastic rheology, weak connection defects and non-welding defects at the interface between passes are eliminated, and the interlayer interfaces are mutually fused to form a good metallurgical bonding interface. In the area to be added, a single layer of material is continuously deposited by repeated metal atomized jet 6 spraying. The material of the sprayed deposited layer is repeatedly stirred, frictionally extruded and stacked, and micro-forging and micro-extrusion rolling are performed on the frictionally extruded and stacked additive layer. The anisotropic cast column / dendritic crystals are transformed into uniform and ultra-fine equiaxed crystals without the texture that is easy to appear in traditional rolling, thus achieving toughness and ultimately achieving the forging structure and performance of the forging. In this way, multi-layer material stacking additive is achieved until the last layer is deposited to reach the additive height required for the composite roll, and the desired 3D printed composite roll component shape with fine and uniform structure is obtained. After repeating the above steps, a 3D printed composite roll component with fine and uniform structure and all metallurgical bonding interfaces can be achieved.

[0057] S10: During the 3D printing manufacturing process, a mobile far-infrared thermometer with a fixed temperature measurement distance installed on the inner wall of the sealed cavity is used to monitor the temperature of the molten metal 14 and the sprayed deposition additive layer at the same distance and synchronously. Multiple high-speed monitoring cameras are also installed at different parts of the inner wall of the sealed cavity to monitor the entire 3D printing composite roll process in the sealed cavity in three dimensions. During the entire 3D printing process, the inert gas pressure in the sealed cavity is also monitored by the air pressure monitoring system. Once the air pressure in the sealed cavity exceeds the rated value, the air pressure regulating valve 24 will automatically open to regulate the inert gas pressure in the sealed cavity.

[0058] S12: After printing is completed, turn off the power supply of the crucible electromagnetic heating induction coil 12 and the roll mandrel electromagnetic heating induction coil 11. After the 3D printed composite roll cools down, turn off the vacuum pump 29 and the inert gas valve to end the 3D printing preparation process. Loosen the hinge bolt 4, open the sealing cavity, and lift the metal melting crucible 13 and the metal liquid 14 guide pipe 8, the inert gas atomizer 7, the stirring friction device 9, and the high-frequency micro forging device 18 on the upper sealing cavity 5 upward. Start the Z-axis lifting mechanism of the vertical high-speed 3D printed composite roll equipment to lift the Y-axis rotation shaft 23, the deposition layer support plate 21, and the 3D printed composite roll upward. Remove the 3D printed composite roll from the deposition layer support plate 21 to finally obtain the 3D printed composite roll component of the required size and shape.

[0059] Furthermore, the 3D printed composite roll mandrel can be made directly using 45# steel, low alloy steel, or high strength and toughness alloy ductile iron mandrels to 3D print composite rolls, or mandrels made from waste rolls of various materials can be used to remanufacture waste rolls into 3D printed composite rolls.

[0060] Furthermore, the composite layer material of the 3D printed composite roll is alloy ductile iron, nickel-chromium-molybdenum alloy cast iron, improved nickel-chromium-molybdenum alloy cast iron, high-chromium cast iron, cast steel, mold steel for hot rolling rolls, mold steel for cold rolling rolls, high-chromium cast steel, semi-steel, high-speed steel, particle-reinforced metal matrix composite material, and cemented carbide material.

[0061] Furthermore, the composite layer material of the 3D printed composite roll can be directly made from roll chip granules;

[0062] Furthermore, the 3D printing composite roll process can also directly 3D print composite tubes when the solid composite roll mandrel is replaced with a tube.

[0063] Furthermore, the preheating temperature of the composite roll mandrel in the 3D printed composite roll is 700-1300℃.

[0064] Furthermore, the jet deposition rate of the 3D printed composite roll is 10Kg~400Kg / h;

[0065] A vertical high-speed 3D printing composite roll equipment includes metal smelting equipment, atomization equipment for preparing metal powder particles, metal particle storage and automatic conveying equipment, a vertical high-speed 3D printing composite roll equipment, equipment control and 3D printing software system, and an inert gas supply system. An X-axis reciprocating moving mechanism 19 is installed on the upper part of the upper sealing cavity 5. A metal melting crucible 13 is installed on the X-axis reciprocating moving mechanism 19. An electromagnetic heating induction coil 12 is installed outside the metal melting crucible 13. A metal liquid 14 guide pipe 8 is installed at the bottom of the metal melting crucible 13, and an inert gas atomizer 7 is installed below the metal liquid 14 guide pipe 8. A stirring friction device 9 is installed on the side of the metal melting crucible 13 in the positive Y-axis rotation direction above the upper sealing cavity 5. A stirring friction motor 10 is installed on the stirring friction mechanism. A high-frequency micro-forging device 18 is installed on the stirring friction device 9 in the positive Y-axis rotation direction. Side view; the micro forging motor 17 is mounted on the high-frequency micro forging device 18; the electromagnetic heating induction coil 11 of the roll mandrel is mounted on the upper part of the inner cavity of the upper sealing cavity 5; a low alloy steel composite roll mandrel 15 or a ductile iron composite roll mandrel 15 or a composite roll mandrel 15 processed from waste rolls is mounted on the deposition layer support plate 21; the deposition layer support plate 21 is mounted on the Y-axis rotation shaft 23; the deposition layer support plate 21 has an inert gas atomizer 7 deposited spray additive layer 20; the Y-axis rotation shaft 23 is mounted on the Z-axis lifting mechanism; a transmission sprocket 27 is mounted on the lower part of the Y-axis rotation shaft 23; the transmission mechanism of the Y-axis rotation shaft 23 is mounted on the Z-axis lifting system 26; the transmission mechanism of the Y-axis rotation shaft 23 drives the Y-axis rotation shaft 23, the deposition layer support plate 21 mounted on the Y-axis rotation shaft 23, and the composite roll mandrel 15 mounted on the deposition layer support plate 21 to rotate in the Y direction through the transmission sprocket 27;The Z-axis lifting system 26 can drive the deposition layer support plate 21 on the Y-axis rotating shaft 23 and the composite roll mandrel 15 installed on the deposition layer support plate 21 to move up and down in the Z direction. A bracket 1 is installed on the Z-axis lifting system 26, and the lower sealing cavity 3 is installed on the bracket 1. A support sleeve 2 is installed on the lower sealing cavity 3, and rotating bearings 22 are installed in the two ends of the support sleeve 2. A vacuum pump 29, a vacuum pump 29 regulating valve, and a vacuum pump 29 connecting pipe 30 are installed below the lower sealing cavity 3. A metal particle 33 storage container 32 is installed next to the outside of the vertical high-speed 3D printing composite roll equipment. The metal particle 33 storage container 32 is equipped with an automatic metal particle 33 conveyor and a particle conveying pipe 35. The upper sealing cavity 5 and the lower sealing cavity 3 are fastened and sealed together by a hinge bolt 4. A pressure regulating valve 24 is installed on the lower part of any side of the lower sealing cavity 3. The lifting ring 16 is installed on the upper part of the upper sealing cavity 5 to facilitate lifting of the upper sealing cavity 5. The synchronous far-infrared thermometer is installed inside the sealing cavity. The high-speed monitoring camera is installed on different parts of the inner wall of the sealing cavity. The equipment control and 3D printing software system is installed on any side of the vertical high-speed 3D printing composite roll equipment.

[0066] Example 2

[0067] A further improvement to this scheme is that the material of the metal melting crucible 13 is graphite, silicon carbide, or a mixture of silicon carbide and graphite, and the heater of the metal melting crucible 13 is a medium-frequency electromagnetic induction heating coil or a high-frequency electromagnetic induction heating coil.

[0068] A further improvement to this solution is that the roller mandrel heater is a medium-frequency electromagnetic induction heating coil or a high-frequency electromagnetic induction heating coil.

[0069] A further improvement of the technical solution of the present invention is that the stirring friction motor 10 is a servo motor or a variable frequency speed control motor;

[0070] A further improvement to the technical solution of the present invention is that the micro forging motor 17 is a servo motor or a variable frequency speed control motor;

[0071] A further improvement of the technical solution of the present invention is that the motor of the X-axis reciprocating movement mechanism 19 is a servo motor or a variable frequency speed control motor.

[0072] A further improvement of the technical solution of the present invention is that the Z-axis lifting transmission motor is a servo motor or a variable frequency speed control motor;

[0073] A further improvement of the technical solution of the present invention is that the Y-axis rotation axis 23 transmission motor is a servo motor or a variable frequency speed control motor;

[0074] The further improvement of this scheme is that the rotational speed of the stirring friction device 9 is 50 to 3000 rpm / min, the axial pressure is 5 kN to 400 kN, and the downward pressure is 0 to 5 mm.

[0075] A further improvement of this solution is that: the toothed friction disc has 1 to 9 spiral ribs on its plane, the height of the spiral ribs on the shoulder plane is 1 to 6 mm, the width of the top of the spiral ribs is 1 to 3 mm, and the inclination angle of the spiral ribs is 5° to 15°.

[0076] A further improvement to this scheme is that the inert protective gas is nitrogen, argon, or a mixture of nitrogen and argon.

[0077] In order to produce metal particles 33 or powder, this equipment naturally includes a metal molten 14 melting equipment, an intermediate ladle for receiving the metal molten 14, an inert gas atomization equipment for preparing metal particles 33 and powder, etc. However, since they can all be assembled using conventional equipment and components, they can be external devices or integrated into the equipment system of this invention for the purposes of this technology, and therefore will not be described here.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A high-speed 3D printing process for composite rolls, characterized in that, Includes the following steps: S1. Metal material preparation: Prepare and smelt metal materials according to the composition requirements, make them into 0.05-6mm granules or powders, and load them into the feeder for later use. S2. Mandrel installation and sealing: Install the composite roll mandrel (15) on the deposition layer support plate (21), merge the sealing cavity and tighten it, and fill it with inert protective gas after vacuuming; S3, mandrel preheating: The composite roll mandrel (15) is moved into the electromagnetic heating induction coil (11) of the roll mandrel through the Z-axis transmission system for heating, and the composite roll mandrel (15) is rotated in the opposite direction through the Y-axis rotation shaft (23) transmission mechanism to ensure uniform heating; S4. Printing preparation: Start the X-axis reciprocating movement mechanism (19) to move the inert gas atomizer (7), stirring friction device (9), and high-frequency micro forging device (18) at the bottom of the metal melting crucible (13) to the starting position of the deposition layer tray (21); S5, Metal Melting Spray: Start the automatic conveyor of metal particles (33) and send the metal particles (33) into the metal melting crucible (13) for heating and melting. The molten metal liquid (14) flows out through the metal liquid guide pipe (8) and is atomized into metal atomized jet (6), which is continuously sprayed and deposited onto the reverse uniformly rotating deposition layer tray (21) and the preheated composite roll mandrel (15) to form a metallurgical bonding interface; S6. Deposition layer treatment: During the continuous jet deposition process, the Y-axis rotation axis (23) continues to rotate in the opposite direction at a certain speed. When the jet additive layer (20) sprayed onto the designed thickness of the deposition layer support plate (21) is rotated by the Y-axis rotation axis (23) to the underside of the stirring friction device (9), the stirring friction motor (10) is started. The friction disk is used to rub, squeeze and stir the deposition layer to refine and homogenize the microstructure of the additive material and improve the interlayer bonding strength. S7. Micro-forging reinforcement: When the friction stir extrusion layer rotates in the opposite direction to the underside of the high-frequency micro-forging device (18), the micro-forging motor (17) is started, driving the high-frequency micro-forging device (18) to perform high-frequency vibration micro-forging and extrusion on the unsolidified friction stir extrusion layer, further improving the density of the additive layer and the interlayer bonding force. S8. 3D Printing Planning: The equipment control system performs layer-by-layer slicing of the 3D CAD model, generates CNC code and plans the forming path, enabling the equipment to perform XYZ 3D motion and 3D printing by layer-by-layer stacking. S9. Layer-by-layer printing: After the first layer of additive manufacturing is completed, the Z-axis lifting system (26) drives the sprayed additive layer (20) and the composite roll mandrel (15) on the deposition layer tray (21) to move downward layer by layer. Repeat the above operation to eliminate the weak connection defects between the passes and form a good metallurgical bonding interface. S10. Process monitoring: During the printing process, the printing process is monitored by an infrared thermometer and a high-speed monitoring camera, and the air pressure monitoring system adjusts the pressure of the inert gas in the sealed cavity. S11. Printing End and Cooling: After printing is completed, turn off the relevant power supply. After the 3D printing composite roll cools down, turn off the vacuum pump and inert gas valve to end the 3D printing preparation process. S12. Component Removal: Loosen the hinge bolt (4), open the upper sealing cavity (5), lift the metal melting crucible (13), the molten metal guide pipe (8), the inert gas atomizer (7), the stirring friction device (8), and the high-frequency micro forging device (18) on the upper sealing cavity (5) upwards, start the Z-axis lifting system (26) of the vertical jet deposition 3D printing composite roll equipment, lift the Y-axis rotating shaft (23), the deposition layer support plate (21), and the 3D printed composite roll upwards, remove the 3D printed composite roll from the deposition layer support plate (21), and finally obtain the 3D printed composite roll component of the required size and shape.

2. The high-speed 3D printing composite roll process according to claim 1, characterized in that: The metal materials used in the composite roll mandrel (15) include, but are not limited to, 45# steel, low alloy steel, high strength and toughness alloy ductile iron and mandrels processed from scrap rolls.

3. The high-speed 3D printing composite roll process according to claim 1, characterized in that: The composite layer material of the 3D printed composite roll includes, but is not limited to, alloy ductile iron, nickel-chromium-molybdenum alloy cast iron, improved nickel-chromium-molybdenum alloy cast iron, high-chromium cast iron, cast steel, mold steel for hot rolling rolls, mold steel for cold rolling rolls, high-chromium cast steel, semi-steel, high-speed steel, particle-reinforced metal matrix composites, cemented carbide materials, and roll chips.

4. The high-speed 3D printing composite roll process according to claim 1, characterized in that: The preheating temperature of the composite roll mandrel is 700–1300℃, and the spray deposition rate is 10Kg–400Kg / h.

5. The high-speed 3D printing composite roll process according to claim 1, characterized in that: The inert gas atomizer (7) causes the molten metal liquid (14) droplets to impact the deposition plate at a high speed of 1-100 m / s during the metal molten spraying process, and at a speed of 10 3 ~10 7 Rapid solidification at an ultra-high cooling rate of ℃ / s results in ultra-fine grains and fine, uniform equiaxed or non-dendritic structures with an average grain size of 1–100 μm.

6. The high-speed 3D printing composite roll process according to claim 1, characterized in that: During the stirring friction process, the rotation speed of the stirring friction device (9) is 50 to 3000 rpm / min, the axial pressure is 5kN to 400kN, the downward pressure is 0 to 5mm, and the toothed friction disc is provided with 1 to 9 spiral ribs on the plane. The height of the spiral ribs on the shoulder plane is 1 to 6mm, the top width is 1 to 3mm, and the inclination angle is 5° to 15°.

7. The high-speed 3D printing composite roll process according to claim 1, characterized in that: During the micro-forging process, the micro-forging motor (17) drives the high-frequency micro-forging device (18) with a servo motor or variable frequency speed control motor as the power source to perform high-frequency vibration micro-forging and extrusion on the unsolidified stirring friction extrusion layer. The extrusion frequency is 50 to 3000 Hz and the extrusion pressure is 5 kN to 400 kN.

8. The high-speed 3D printing composite roll process according to claim 1, characterized in that: In the 3D printing planning step, the equipment control system performs layer slicing processing according to the size and accuracy requirements of the 3D CAD model. The generated CNC code includes XYZ 3D motion path planning, and the thickness of each spray deposition layer is 0.5 to 5 mm.

9. The high-speed 3D printing composite roll process according to claim 1, characterized in that: In the layer-by-layer printing step, when the subsequent layers are stacked in the area to be added, the flow rate of the molten metal (14) is controlled by adjusting the speed at which the metal particles (33) are fed into the molten metal crucible (13), and the temperature fluctuation range during the printing process is controlled within ±10℃.

10. A high-speed 3D printing composite roll equipment, characterized in that: The equipment uses the high-speed 3D printing composite roll process described in any one of claims 1-9 to prepare composite rolls.

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