A powder bonding system for additive manufacturing.

Abstract

The invention is a powder bonding system for additive manufacturing, comprising a table (21) on which metal, ceramic or polymer powders are deposited and which can move vertically up and down, a powder dispensing unit (10) with a powder hopper which performs the powder dispensing operation on the table (21), a vertical axis (30) to enable the up and down movement of the table (21), an opening (46) with a capillary structure or micron-sized opening through which the fluid exits and is dispensed onto the powder; the dispensing of the fluid onto the powder is carried out by capillary and adhesive forces, the fluid exits and forms a meniscus, this dome makes contact with the powder, a dosing unit (40) with a positive displacement pump structure which adjusts or maintains the pressure at the end of the opening (46), and horizontal axes (90) attached to the frame (70) to enable the movement of the opening (46) in the X and Y axes.

Description

1 TARIFF A powder bonding system for additive manufacturing. Technical Area The invention relates to a powder coupling system for additive manufacturing. State of the Art 5 Additive manufacturing techniques have emerged as a recent alternative to traditional machining methods. These techniques have been developing rapidly in recent years and are becoming widespread in industrial applications. Among them are powder bed additive manufacturing systems, for parts with complex geometries. It offers significant advantages in production. In powder bed systems, metal, ceramic or The binder liquid is applied over layers of polymer powders, and then 10 A manufacturing process based on obtaining the final part through a sintering process. is being implemented. In current applications, the transfer of the binder liquid to the powder bed is predominantly performed. Inkjet technology is used. Inkjet-based systems utilize piezoelectric or thermal energy. By means of actuators, binder droplets are applied to the powder surface at a specific speed. 15 It sprays. This approach is suitable for low viscosity and a narrow surface tension range. It is limited to compatible connectors. In the literature, inkjet printheads typically have 2 to It can operate effectively in the viscosity range of mPa·s and in fluids outside this range. problems such as nozzle clogging, droplet formation disorders, and inconsistent spraying during use Problems are seen to be emerging. 20 One of the main limitations of inkjet systems is that the binder is in powder or droplet form. This spraying mechanism causes uneven wetting of the powder layer. This leads to uncontrolled lateral spread of the binder and its behavior. Especially the use of binders with high surface energy or reactive binders. In this case, non-homogeneous bonding occurs between dust particles and interlayer 25 Problems such as weak cohesion are observed. This situation affects the mechanical properties of the manufactured parts. This leads to a decrease in features and a reduction in dimensional accuracy. In current systems, flow control is mostly achieved through pressure changes or thermal expansion. This is done based on its principles, ensuring a sudden and precise flow of fluid. This makes it difficult to stop. This technical limitation applies to microliters or smaller (30). 2 This makes dosing in large volumes difficult, especially on a micro-scale or very large scale. This leads to a decrease in surface solubility in material-based production. Additionally, the nozzle... Increased risk of clogging and direction of binding droplets due to decreasing diameter This deviation negatively affects production quality. As a result, the existing inkjet-based powder Binding systems, capable of operating in a wide viscosity range, micro-level binder diffusion. It falls short in terms of level control and increasing material variety. In micro, nano and pico-scale liquid dosing and droplet formation applications. piezoelectric or thermal inkjet heads, vibrating nozzles, and various electromechanical systems. Converters are widely used; technical solutions in this field and their The limitations apply to applications numbered US 2007210677 A1 and US 6874699 B2. Most inkjet and binder-jet approaches are detailed for low to medium viscosity. It is designed to work efficiently with binders (generally in the range of ≲1–20 mPa·s); In contrast, high viscosity, high surface tension, or particle-rich Micro-dosing of binders is problematic due to issues of reliability, clogging, and repeatability. difficult (e.g., US 2024017484 A1). 15 In application number US 6874699 B2, the fluid is introduced using a pipette-like device made from a tube. Liquid is drawn into the reservoir by immersion and then dripped onto the surface with the help of a piezoelectric device. It is mentioned that the reservoir is being accumulated. However, this application does not include pressure control on the reservoir. the absence of, different fluids can be used safely and predictably. It restricts and narrows the fluid selection. Also, the process requires a smooth surface like glass. 20 It was carried out on it, and since the fluid control level is low, adhesive and Due to the effect of cohesive forces, the liquid only adheres to smooth surfaces; therefore It is possible to reliably deposit liquids on porous or particle-bedded surfaces. It is not visible. In case of uncontrolled applications, clumping occurs upon contact with dust. and the risk of uneven distribution increases significantly. 25 Current binder spraying and nozzle techniques accommodate binders with varying viscosities and surface tensions. Binders are powdered in a micro-scale, precise, repeatable manner with a low risk of clogging. It is unable to ensure controlled spreading on the surface; as a result, in the powder bed homogeneous bonding, high surface solubility and predictable mechanical properties are achieved. It is becoming difficult to achieve this. In drip-spray based systems, the droplet must reach a certain point in time (30...). Spraying from a height and hitting the dust at a certain speed causes uncontrolled wetting and Interlayer heterogeneous bonding due to irregular spreading of the binder, surface This leads to loss of solubility and variability in mechanical strength (e.g., US). 3 2024017484 A1; US ​​2007210677 A1). Contactless, remote drop inkjet technology. Its reliance on spraying also affects the fluid properties during application. It imposes restrictions. In conclusion, due to the negative aspects described above and the current solutions being the subject of discussion... Due to its shortcomings, an improvement in the relevant technical field is necessary. 5 It has been made. Purpose of the Invention The invention was created by drawing inspiration from existing situations and overcoming the aforementioned drawbacks. It aims to solve the problem. The invention relates to additive manufacturing techniques in powder bed additive manufacturing systems. It relates to a powder binding system developed for use. The main purpose of the invention is: binder on a powder bed consisting of powders such as metal, ceramic or polymer powders The liquid is applied using a spreading method, taking advantage of the capillary effect, in a precise and controlled manner. The goal is to offer a system that enables the spreading of materials. This system utilizes three-dimensional printing. a technical infrastructure that can be applied in the development and production processes of functional structures 15 It constitutes. The invention addresses the narrow viscosity range and limited surface area of ​​existing inkjet-based spray systems. It aims to overcome limitations such as voltage tolerance. For this purpose, the dosing unit and a system that controls the precise outflow of fluid through displacement providers. A mechanism has been developed. The system uses a displacement generator (piezoelectric, electrostrictive, 20 (such as magnetostrictive, electrostatic or electromagnet-based transducers, etc.) By using it, it is possible to efficiently utilize fluids with different rheological characteristics. This enables a wide viscosity spectrum, from below 1 mPa·s to 5,000,000 mPa·s. The ability to operate in a range extending up to and above mPa·s is ensured. One of the distinctive features of the invention is that the binder liquid is applied to the powder surface instead of being sprayed on 25 It is the transfer of electricity through the spreading technique. Electricity is generated via displacement providers. signals, volumetric deformation within the fluid, and micro-scale pressure waves This creates pressure waves. When these pressure waves are combined with flow rate and pressure control, precise adjustment of the fluid and its retraction when necessary at the nozzle tip. It ensures that clogging or droplet accumulation is prevented. Thus, binder 30 Instead of falling as droplets onto the powder, it spreads through contact and capillary action. 4 and a stable, homogeneous distribution is obtained on the powder surface. Continuous liquid contact. Thanks to this, a continuous and stable binding bridge is formed, which makes the manufactured parts It provides a smooth finish on the edges. In addition to displacement sensors positioned along the fluid path, the system also includes: It includes a pressure control unit located on the reservoir. This dosing unit has a screw shaft 5 positive displacement pumps such as piston mechanisms, peristaltic pumps, or micropumps It allows precise adjustment of the fluid flow rate through the systems. It is also known. In addition, the temperature of the liquid and powder bed is controlled by heaters and sensors. By doing this, the rheological properties of the fluid are kept within the desired range, and Thus, highly precise adjustments can be made. 10 The invention applies not only to standard binding fluids, but also to those containing functional particles. This capability also makes it possible to distribute the fluids containing these substances onto the powder surface. It facilitates the creation of composite structures and produces stronger structures with desired properties. It enables the development of new materials with three-dimensional structures. The fluid Polymer structures with conductive channels through which they are passed by being modified at certain stages. 15 or structures containing patterns with different functional characteristics can be produced. This Printed areas with different fluids, such as conductivity, strength or thermal management. It can be used for these purposes. In conclusion, the invention offers a wide range of liquid selection, stable and precise flow control, and powder resistance. micro-scale liquid transfer to the surface and dispersion of different materials onto the powder 20 by combining capabilities such as these, new composite and alloy materials are being developed. This approach enables the development of existing binder jetting and inkjet. eliminating the technical shortcomings of powder bed additive manufacturing systems It significantly expands the application area of ​​these techniques. The structural and characteristic features and all the advantages of the invention are given in the figures below and 25 This becomes clearer thanks to the detailed explanation written with references to these figures. This will be understood, and therefore the evaluation should also take these forms and detailed explanations into consideration. It needs to be done by taking precautions. Figures that will help understand the invention. Figure 1 shows the appearance of the system that is the subject of the invention. 30 Explanation of Part References Powder spreading unit 21 Tables Vertical axis 40 Dosing units 5 41 Reservoirs 42 Pipes 43 Valves 44 Valves 45 Away providers 10 46 Openings 60 Control units 70 Skeletons 80 Dust collector units 90 Horizontal axes 15 Detailed Description of the Invention This detailed description outlines a powder coupling system for additive manufacturing, which is the subject of the invention. preferred structures are solely for the purpose of better understanding the subject. It is explained. The subject of the invention is the physical infrastructure of the powder bonding system for additive manufacturing. skeleton (70), the main load-bearing structure that carries all axis systems and structural components. It consists of elements. The frame (70) can hold electrical cables where necessary. It can contain internal channels that ensure secure transmission and can carry XYZ Limit switches can be positioned in the coordinate system. This framework horizontal axes (90) that provide the system's mobility, based on its structure (70) 25 It is connected. The horizontal axes (90) are precisely connected to the opening (46) in the X and Y coordinate plane. It includes drive mechanisms that make its movement possible. These drive systems are belt-driven. in various forms such as pulleys, hydraulic actuators, or screw shafts It can be designed. Drying of the binder fluid on the horizontal axes (90). Heating elements that can be used for this purpose, infrared lamp, near-infrared lamp, flash 30 energy sources such as lamps, microwave generators or ultraviolet lamps They can be positioned. Additionally, limit switches can be placed along these axes. It can be installed. 6 The vertical movement capability of the system is provided via the vertical axis (30). The axis (30) is the mechanism that performs the upward and downward movement of the table (21). It includes various drive systems such as hydraulic, screw shaft, chain or belt pulley mechanisms. It can be implemented in the form of systems. There are also limits for position control on this axis. Keys can be found. The table (21) is positioned on the vertical axis (30). by precisely moving it downwards in intervals equal to the thickness of the layer, each It allows for the application of a layer of powder. The table (21) constitutes the work area where the printing process is actually carried out. This The table (21) has the ability to move up and down on the vertical axis and three It represents the basic surface on which the three-dimensional structure is built layer by layer. Table (21) 10 Powder material is spread on it in the thickness determined by the powder spreading unit (10). The powder spreading unit (10) performs the powder spreading process on the table (21) and contains powder It is a subsystem containing a hopper. This unit (10) has blades or rollers for spreading powder. It can use leveling elements such as. Powder inside the powder spreading unit (10) The hopper will rise a certain amount so that the amount of powder to be spread on the table (21) is 15 It ensures adjustment. Excess dust that remains relatively high on the table (21), It is spread onto the table (21) to a certain thickness by means of rollers or blades and The remaining amount of dust flows into the dust collector unit (80) hopper. Here, the relative amount The height can also be created by lowering the table (21). As an alternative application, The powder spreading process can also be carried out entirely manually, with a certain amount of powder applied in 20 seconds. by placing it on the table (21) and using a flat plate or knife by hand It can spread. Dust collector unit (80), channel where excess dust is collected after dust spreading process. It forms the structure. When the powder spreading process takes place, the surface of the table (21) The excess dust remaining on top is poured into the dust collector unit (80) channel. Required 25 In these cases, this unit (80) can be equipped with a vacuuming feature and the collected dust is more It can then be mixed with fresh powder and reused. The system's liquid transfer mechanism is controlled by the dosing unit (40). The dosing unit (40) is a positive displacement pump and precisely displaces the liquid. It provides control. Dosing unit (40), screw shaft, reducer, belt pulley 30 Dosage unit (40), may include elements such as mechanisms and syringe assembly. It performs the function of adjusting or maintaining the pressure at the end of the opening (46). and contains a heater, temperature sensor, flow rate sensor, pressure sensor and volume sensors. 7 Measurement and control elements such as dosing unit (40), piston syringe may be included. It can be designed in a type of structure and flow from its reservoir to the opening (46). can send. The system may have one or more reservoirs (41) connected to the dosing unit (40). These reservoirs (41) allow for the storage of different binding fluids, as well as 5 It also functions as a reservoir for liquids or solutions used to clean the system. It can be seen. The reservoirs (41) are connected to the valve (43) by means of the pipe (42). Pipe (42) is connected to the dosing unit (40) from the peak point, thus violating the laws of physics. The system ensures that the air rises to the top as appropriate. Valve (43), reservoir 10 related to dosing unit (40) during air removal and filling operations. It controls the connection between (41). When the relevant reservoir (41) pathway is opened at valve (43), Liquid flow can occur from the reservoir (41) to the dosing unit (40). Air removal process During this time, the valve (44) is closed, and the path to the relevant reservoir (41) is opened by the valve (43). It opens and the dosing unit (40) displaces the air inside the reservoir (41) by positive displacement. It discharges into the unit. During this process, the piston experiences a positive displacement of 15 in the downward direction. to perform the movement, air passes into the chambers (41) inside the piston and then the piston by moving in the opposite direction, the liquid inside the reservoir (41) passes into the piston reservoir. This allows both air intake and filling to be performed simultaneously. In addition, filling can be done through the opening (46) by opening valve (44) and closing valve (43). It is possible. 20 The valve (44) prevents or allows flow between the dosing unit (40) and the opening (46). It functions as a control element that provides filling and air. This valve (44) is especially important for filling and air. It plays an important role during the purchasing process. One of the most characteristic elements of the system is the one positioned along the fluid path. is a displacement provider. (45). In the invention, one or more displacement providers (45) 25 Displacement provider (45), piezoelectric, electrostrictive, in displacement-actuating structures such as magnetostrictive, electrostatic or electromagnetic. It can be selected. The main purpose of the displacement provider (45) is to provide volumetric electrical signal. By creating deformation, micro-scale pressure waves are generated in the fluid. The aim is to bring about this. In addition to these pressure waves and the displacement caused by the pressure, the flow is 30 It can be precisely adjusted with flow rate and pressure control, and liquid return can be performed when necessary. By pulling, clogging or droplet accumulation at the nozzle tip can be prevented. Displacement The provider (45) is effective in the formation of the meniscus, with dense fluids or 8 It can cause fluids that do not leave the nozzle to be separated by sudden impacts, preventing clogging. In situations like these, it can clear the blockage with instantaneous bursts of pressure. The opening (46) is such that it is in a capillary structure or micron size. The fluid, this It is spread on the dust coming out of the opening (46). The opening (46) is horizontal axes (90) By moving it along the X and Y coordinate planes, it can be moved to the desired points. 5 It can be positioned. All operational control of the system is provided by the control unit (60). The control unit (60) includes the power supply and microprocessors, and the horizontal axis (90) and Control of vertical axes (30), control of displacement providers (45), dosing unit (40), Control of valve (43) and valves (44) is done by microprocessors (60) in the mentioned control unit 10 This is achieved through monitoring temperature, pressure, and all other sensor data. It is transmitted to the control unit (60). Through a memory card to be inserted into the control unit (60). The digital model of the three-dimensional structure to be printed can be uploaded to microprocessors. This process Alternatively, it can also be provided via direct computer connection. Control unit (60) Additionally, there are screens and / or buttons that the user can use to modify the settings. It may include. The operating principle of the system described in the invention is as follows: The system works by dividing a three-dimensional object into layers using a slicing program. It begins with defining the necessary processing steps for each layer. This slicing... The result of the process is a code 20 that indicates which areas in which layer the fluid will be injected. A code block is created. Within the code block, which opening (46) is in each layer orders specifying where to go and how much fluid to release It is located. Also, within the code block, it will be sent to the dust spreading unit (10). The commands are also available in sequence. This code is for the microprocessors (60) in the control unit. It is prepared in a format that they can understand. 25 The code of the sliced ​​three-dimensional object is checked using a memory card or a computer. The data is transferred to the microprocessors in the unit (60). The control unit (60) is used in the production process. Before starting, the necessary preliminary preparations are made. These preliminary preparations include aligning the axes with the origin. gradually resetting to zero, bringing temperatures to appropriate levels and similar calibrations It includes the operations. Limit 30 placed on the skeleton (70) and axes (90, 30). Switches and position switches are used in these calibration procedures and during operation. It is used to ensure safe working conditions. 9 The production process involves laying the powder layer thickness thanks to the vertical axis (30) of the table (21). It starts with the downward movement of the powder spreading unit (10), table (21) It spreads the dust on top. Excess dust is poured into the dust collector unit (80). Dust After the spreading unit (10) is withdrawn from the table (21), the horizontal axes (90) opening (46) It moves along the X and Y axes to the coordinates specified in the code. 5 The opening (46) is at a certain distance from the dust so that it does not touch the dust when it comes into contact with it. It is positioned. The fluid is displaced with the help of the dosing unit (40). The fluid passes through a channel actuated by displacement agents (45) into the opening (46) It reaches. The fluid exits through the opening (46) and forms a meniscus. This A contact occurs when the domed liquid surface touches the powder. As a result of this contact, 10 The dispersion of the fluid into the powder occurs through capillarity and adhesive forces. Displacement providers (45) play an important role in the controlled formation of the meniscus. He is playing. The dosing unit (40) and the displacement provider (45) are coordinated with the horizontal axis (90). As a result of the study, fluid is distributed to all designated areas in the first layer. The first 15 After the process of spreading fluid into the layer is completed, the opening (46) is in a specific area The heater, infrared lamp, is pulled and, where necessary, is connected to the horizontal axis (90), via near infrared lamp, flash lamp, microwave generator or ultraviolet lamp The printed areas are dried by exposing them to heat. After a layer is completed, the vertical axis (30) moves the table (21) to the next 20 It lowers the layer thickness by the amount of the powder spreading unit (10) again powder spreading The process is carried out and excess dust is discharged into the dust collector unit (80). After the powder spreading unit (10) is pulled over the table (21), the second layer is printed. The opening (46) progresses again towards certain regions on the horizontal axis (90). This As a result of repeated processes, the final three-dimensional object will be 25, depending on the material used. The component is built layer by layer. In the first filling operation, a will be placed under the opening (46) and will be submerged into the opening (46). Liquid can be drawn from the reservoir (41) using a syringe. In this way, the system The system is being made easier to prepare and bring into operation for the first time. This integrated working structure enables precise 30° processing of fluids with varying viscosities and surface tensions. This enables controlled application of the powder to the surface, thus creating a high-quality three-dimensional effect. The construction of structures is being carried out.

Claims

REQUESTS 1. It is a powder bonding system for additive manufacturing, and its characteristic feature is;  where powders such as metal, ceramic or polymer powders are spread and vertically upwards a table that can move downwards (21),  A powder dispenser with a powder container that performs the powder spreading operation on the table (21) 5 Spreading unit (10),  A vertical axis (30) to enable the table (21) to move up and down,  having a capillary structure or a micron-sized opening through which the fluid passes It emerges from this opening and is spread onto the powder; capillary and adhesive forces 10 the fluid leaks out and forms a meniscus, this bulge comes into contact with dust an opening that creates contact (46),  The pressure at the end of the opening (46) of a positive displacement pump structure a dosing unit that adjusts or keeps fixed (40),  The movement of the opening (46) in the X and Y axes, which is attached to the skeleton (70) 15 horizontal axes (90) to provide It includes.

2. A system conforming to Claim 1, with the following features: hydraulic, screw shaft, chain or belt pulley. It includes a vertical axis (30) which contains the mechanism.

3. System conforming to Request 1 or 2, with the following features: screw shaft, gearbox, belt pulley 20 It includes a dosage unit (40) with mechanisms and syringe assembly.

4. A system that meets any of the previous requirements and whose feature is; it contains a heater, a dosing unit containing temperature sensor, flow rate, pressure and volume sensors (40) It includes.

5. A system that meets any of the previous requirements and has the characteristic of having 25 on the fluid path. positioned, creating volumetric deformation of the fluid with an electrical signal creating micro-scale pressure waves on the surface and causing the fluid to retract through the nozzle. at least one displacement provider that prevents clogging or droplet accumulation at the tip (45) It includes. 11 6. The system conforms to claim 5 and has the following characteristics: piezoelectric, electrostrictive, magnetostrictive, displacement provider of electrostatic or electromagnetic structure (45) It includes.

7. A system that conforms to any of the previous requirements and whose characteristic is; drive mechanisms. horizontal axes containing and consisting of belt pulley, hydraulic or screw shaft structures 5 (90) is included.

8. The system is suitable for any of the previous requirements and its feature is; dust spreading unit (10) The dust container inside will be lifted up a certain amount and spread on the table (21). the amount of dust is adjusted and the dust that remains relatively high on the table (21) is rolled or by means of blades, the system is spread onto the table (21) to a certain thickness 10 It includes.

9. The system is suitable for any of the previous requirements and its feature is that the table (21) has a certain The amount of powder to be spread on the table (21) is adjusted by going down and on the table (21) Dust that remains relatively high according to the dust spreading unit (10) is rolled or It is a system that involves spreading the material onto the table (21) to a certain thickness by means of blades. 15 10. The system is suitable for any of the previous requirements and its feature is; vertical axis (30) It contains limit switches.

11. A system that meets any of the previous requirements and whose characteristic is a piston syringe type. The dosing unit (40) is in the structure and sends flow from its own reservoir to the opening (46) It includes. 20 12. The system conforms to requirement 5 or 6 and its characteristic is that it handles viscous fluids or fluids from a nozzle. separating non-separable fluids with sudden pulses and instantaneous response in case of blockage. It contains a displacement provider (45) that relieves the blockage with impacts.

13. The system is suitable for any of the previous requirements and its feature is; horizontal axes (90) Heater, infrared lamp, near infrared 25 for drying the binding fluid on it. at least one of the following: lamp, flash lamp, microwave generator or ultraviolet lamp It is the presence of.

14. The system is suitable for any of the previous requirements and its feature is; horizontal axes (90) It contains limit switches. 12 15. A system that conforms to any of the previous requirements and has the characteristic of being: different binding liquid to be used for storing fluids or cleaning the system At least one reservoir (41) connected to the dosing unit (40) which functions as a solution reservoir It includes.

16. The system is in accordance with claim 14 and its feature is that the reservoirs (41) are connected by a pipe (42) to a 5 connected to the valve (43) and the valve (43) connected to the dosing unit (40) of the desired liquid It is the system that it creates or disconnects from the reservoirs (41).

17. The system is in accordance with claim 15 and its feature is the distance between the dosing unit (40) and the opening (46). whether it blocks or allows flow; between the dosing unit (40) and the opening (46) It contains a valve (44). 10 18. A system that meets any of the previous requirements and whose feature is; powder spreading process. It contains a dust collector unit (80) where the excess dust is collected.

19. System conforming to Claim 17; its feature is a dust collector with vacuuming capability. It contains unit (80).

20. A system that conforms to any of the previous requirements and has the following features: axis systems and 15 It carries structural components and through which electrical cables are transmitted. capable of hosting channels that provide limits in the XYZ coordinate system. It contains a skeleton (70) in which the keys can be positioned.

21. A system that meets any of the previous requirements and whose features include: power supply and 20 containing microprocessors, controlling the horizontal axis (90) and vertical axes (30). Control of the displacement providers (45), control of the dosing unit (40) and It includes a control unit (60) through which temperature, pressure and other sensor data are transmitted.

22. The system is suitable for any of the previous requirements and its feature is; the control unit (60) the screen or buttons that allow the user to interact with the settings, and the memory card. It includes sockets for connection or computer connection. 25