Additive manufacturing system, additive manufacturing method, and computer-readable medium

Abstract

The present application provides an additive manufacturing system. The additive manufacturing system includes: a plurality of conveying pipes, each of which is connected to a material source; a mixer, the plurality of conveying pipes being connected to the mixer, the mixer being configured to mix the powder materials supplied via the plurality of conveying pipes in real time during additive manufacturing; and a nozzle, the mixer being connected to the nozzle via a supply pipe, the nozzle being configured to transport the mixed mixed material to a substrate for additive manufacturing, wherein each of the plurality of conveying pipes is configured to be able to change the conveying amount or conveying speed of the powder material in real time. The present application also provides an additive manufacturing method for the above-mentioned additive manufacturing system. The above-mentioned additive manufacturing system and additive manufacturing method are capable of adjusting the material composition or its proportion in real time to meet the different performance requirements of different parts of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of material processing, and in particular, to an additive manufacturing method and an additive manufacturing system for forming a product by performing additive manufacturing using a heat source such as a laser and an electric arc. Background Art

[0002] High-entropy alloys (HEAs) are formed by alloying multiple elements (usually five or more) in specific proportions, with the content of each element ranging from 5% to 35%. This results in a higher mixing entropy than the melting entropy of traditional alloys. HEAs possess superior properties unmatched by traditional alloys, such as high strength, hardness, wear and corrosion resistance, thermal resistance, and electrical resistance. The properties of HEAs can be modified by varying the elements or their proportions.

[0003] When manufacturing high-entropy alloy products, for example, using existing additive manufacturing methods, multiple material elements are first mixed together in a certain proportion. The additive manufacturing system is then turned on to process this constant-proportion mixture to form the final product. In these existing additive manufacturing methods, because the mixing step is completed before additive manufacturing begins, the material elements or their proportions cannot be changed in real time or precisely during additive manufacturing. Consequently, only products with uniform properties can be produced, rather than high-entropy alloy products with functional gradients—that is, alloy products with gradually varying properties such as material strength—that meet specific requirements. Furthermore, unused mixed raw materials can be wasted. Summary of the Invention

[0004] An object of the present invention is to provide an additive manufacturing method and an additive manufacturing system capable of changing the amount of powder material in real time and / or accurately.

[0005] According to one aspect of the present disclosure, an additive manufacturing system is provided. The additive manufacturing system includes: a plurality of delivery pipes, each of which is connected to a material source; a mixer, to which the plurality of delivery pipes are connected, the mixer being configured to mix different types of powder materials supplied along with an airflow via the plurality of delivery pipes in real time during additive manufacturing; and a nozzle, to which the mixer is connected via a supply pipe, the nozzle being configured to deliver the mixed material to a substrate for additive manufacturing. Each of the plurality of delivery pipes is configured to be capable of varying a delivery amount or delivery speed of the powder material in real time.

[0006] In the additive manufacturing system disclosed herein, since multiple delivery pipes are connected to the mixer, and the mixer is connected to the nozzle, powder materials can be supplied and mixed in real time along with the inert gas. An inert gas, such as helium or argon, is delivered along with the powder materials, and the delivery speed of the powder materials can be varied by changing the speed of the inert gas, thereby varying the amount of powder materials supplied. In this way, the additive manufacturing system disclosed herein can provide flexibility in material supply. For example, the supplied powder materials or their proportions can be varied in real time, thereby meeting the varying performance requirements of different parts of a product.

[0007] In some examples of additive manufacturing systems, the nozzle has an inner wall and an outer wall defining an annular space therebetween to receive the mixed material.

[0008] In some examples of the additive manufacturing system, a laser or an arc welding device for melting the mixed material is further included, wherein the inner wall of the nozzle is configured to allow a laser of the laser or an electrode of the arc welding device to pass through.

[0009] In some examples of additive manufacturing systems, the inner wall and the outer wall of the nozzle are coaxially arranged. This arrangement makes it easier for the mixed material to be concentric with the heat source, thereby improving product quality.

[0010] In some examples of additive manufacturing systems, each of the inner wall and the outer wall of the nozzle includes a cylindrical section and / or a conical section.

[0011] In some examples of the additive manufacturing system, a controller is further included, which realizes real-time control of the conveying amount or conveying speed of the powder material in each of the plurality of conveying pipes.

[0012] In some examples of the additive manufacturing system, a heating device for heating the substrate and / or the mixed material is further included.

[0013] According to another aspect of the present disclosure, an additive manufacturing method is provided. The additive manufacturing method includes: delivering different types of powder materials from a material source to a mixer via multiple delivery pipes; mixing the powder materials in real time in the mixer; and transporting the mixed materials via a nozzle along with an airflow onto a substrate for additive manufacturing. The delivering of the powder materials via the multiple delivery pipes includes varying a delivery amount or delivery speed of the powder materials in real time.

[0014] In some examples of the additive manufacturing method, the method further includes a step of loading product manufacturing data and control parameters into a controller before conveying the powder material from the material source, so as to control the conveying amount and conveying speed of the powder material according to the loaded data.

[0015] In some examples of the additive manufacturing method, the step of melting the mixed material by a laser or an arc welding device is further included.

[0016] In some examples of the additive manufacturing method, the method further includes providing a shielding gas to an electrode of the arc welding device during melting of the mixed material by the arc welding device.

[0017] In some examples of additive manufacturing methods, when the mixed material is melted by a laser, the nozzle and the laser beam are perpendicular to the substrate or at a predetermined angle relative to the substrate, and the mixed material is discharged onto the substrate around the laser beam.

[0018] In some examples of the additive manufacturing method, when the mixed material is melted by an arc welding device, the nozzle and the electrode of the arc welding device are angled with the substrate, and the mixed material is discharged onto the substrate around the electrode.

[0019] In some examples of additive manufacturing methods, the substrate and / or the mixed material may be heated by a heating device during the manufacturing process. This can reduce the temperature gradient between the powder material and the molten pool, thereby minimizing the temperature gradient and improving the quality of the additively manufactured structural part.

[0020] The additive manufacturing method according to the present application may have the same or similar technical effects as the above-mentioned additive manufacturing system.

[0021] According to another aspect of the present disclosure, a computer-readable medium is provided, wherein a program is stored on the computer-readable medium, and when the program is executed by a processor of a control unit, the additive manufacturing method described above is implemented.

[0022] Other advantages and features of the present invention will become apparent from the following non-limiting detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The features and advantages of one or more embodiments of the present invention will become more readily understood through the following description with reference to the accompanying drawings, in which:

[0024] Figure 1 is a schematic structural diagram of an additive manufacturing system according to an embodiment of the present disclosure;

[0025] Figure 2 is a schematic structural diagram of an additive manufacturing system according to another embodiment of the present disclosure; and

[0026] Figure 3 Schematic diagram of the process of the additive manufacturing method according to an embodiment of the present disclosure.

[0027] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and exemplary embodiments. The following detailed description of the present invention is for illustrative purposes only and is in no way intended to limit the present invention, its application or use.

[0029] Figure 1 is a schematic structural diagram of an additive manufacturing system 10 according to an embodiment of the present disclosure. Figure 1 The additive manufacturing system 10 in the embodiment uses laser as a heat source, and therefore may also be referred to as a laser additive manufacturing system in this article. Figure 1 As shown, the additive manufacturing system 10 includes a plurality of delivery pipes PF1 to PF6 for delivering raw materials, a mixer 110 , a supply pipe 112 , a nozzle 120 , a laser 130 , an optical device 132 , a substrate S, and heaters H1 and H2 .

[0030] A plurality of delivery pipes PF1 to PF6 connect a material source (not shown) to the mixer 110 so as to supply the material from the material source to the mixer 110. As needed, the delivery pipes PF1 to PF6 can be connected to different material sources, or some of the delivery pipes PF1 to PF6 can be connected to the same material source (e.g., a material source with a larger content requirement to meet the required amount). The delivery pipes PF1 to PF6 can be used to transport metal powder material.

[0031] A gas supply device may be provided at the powder material conveying pipes PF1 to PF6 to supply an inert gas, such as helium or argon, into the powder material, so that the inert gas carries the powder material into the mixer 110 .

[0032] Each of the multiple delivery pipes PF1 to PF6 can be configured to adjust the material delivery rate or delivery speed in real time during additive manufacturing. For example, the powder material delivery speed, and thus the powder material delivery rate, can be varied by changing the flow rate of the inert gas. Alternatively, valves can be provided in the delivery pipes PF1 to PF6 to control whether the pipe is open or closed, or the degree of opening to control the delivery speed. In another embodiment, the material delivery speed can be varied in real time by controlling the rotational speed of a screw propeller installed in the delivery pipe.

[0033] The material feed rate can be, for example, in the range of 0 g / min to 20 g / min. The material feed rate can be adjusted in real time according to the model data of the product to be processed to manufacture a functionally graded high entropy alloy product.

[0034] The mixer 110 is coupled to the nozzle 120 via a supply pipe 112. During additive manufacturing, various materials delivered via the delivery pipes PF1 to PF6 are mixed in real time in the mixer 110. The material MM mixed in the mixer 110 is supplied to the nozzle 120 via the supply pipe 112. The mixer can be implemented as various existing mixing devices, such as a spiral stirring mixing device.

[0035] The nozzle 120 is configured to discharge the mixed material MM mixed in the mixer 110 and supplied through the supply pipe 112 onto the substrate S moving relative to the nozzle for additive manufacturing, see the material layer ML in the drawing.

[0036] exist Figure 1 The additive manufacturing system 10 shown can supply and mix materials in real time during additive manufacturing, and change the material composition or ratio in real time, thereby meeting the different performance requirements of different parts of the product. The material supply can be changed in real time according to actual needs, thus providing great flexibility.

[0037] exist Figure 1 In the example shown, the nozzle 120 has an inner wall 124 and an outer wall 122. An annular space is formed between the inner wall 124 and the outer wall 122 to receive the mixed material MM. The interior space defined by the inner wall 124 allows the laser beam 134 to pass through. The lower end of the outer wall 122 may be provided with an opening 121 to facilitate depositing the mixed material MM within the annular space onto the substrate S. The mixed material MM emerging from the opening 121 surrounds the laser beam 134, allowing the mixed material MM to be uniformly heated and melted. In other words, the mixed material MM emerging from the opening 121 can accurately fall into the effective heat source area.

[0038] The inner wall 124 and the outer wall 122 of the nozzle 120 may be coaxially arranged, that is, the central axis of the inner wall 124 coincides with the central axis of the outer wall 122. Figure 1 In the example shown, the inner wall 124 of the nozzle 120 is generally conical. The outer wall 122 comprises a cylindrical section 122a and a conical section 122b. The lower end of the conical section 122b forms an opening 121. The conical section 122b can constrict the laser plasma, the powder beam, and the shielding gas range, thereby increasing the heat source energy density. It should be understood that the shape of the nozzle 120 is not limited to the specific example shown and can be modified according to specific needs.

[0039] The laser beam 134 generated by the laser 130 irradiates the material layer ML after passing through the optical device 132 and the inner space within the inner wall 124 , melting the mixed material at the irradiated position to form a molten pool MP.

[0040] The additive manufacturing system 10 may further include a shielding gas supply device (not shown) to supply shielding gas PG into the annular space between the inner wall 124 and the outer wall 122. For example, the shielding gas may flow through the nozzle 120 at a rate of 5 ml / min to 300 ml / min, or alternatively 5 ml / min to 200 ml / min.

[0041] Before or during additive manufacturing, the supplied mixed material may be heated by a heater H1 and / or maintained at a temperature within a predetermined range, for example, 50° C. to 250° C. The heater H1 may be provided on the supply pipe 112 to heat the mixed material as it passes through the supply pipe 112. The provision of the heater H1 may reduce the temperature gradient between the mixed material and its melting point, thereby improving the quality of the molded product.

[0042] Before, during, or after additive manufacturing, the substrate S can be heated by a heater H2. Furthermore, the substrate S can heat the material layer ML and / or maintain its temperature within a predetermined range, such as 100°C to 300°C. The heater H2 can be located on one side of the substrate S (the lower side in the figure). The provision of the heater H2 can reduce stress and deformation in the high-entropy alloy product.

[0043] Heater H1 and heater H2 constitute the heating device described herein. The heating device can be a resistance heating device or an electromagnetic heating device. It should be understood that the heating device can also be any other suitable heating device, such as an electron beam.

[0044] The additive manufacturing system 10 includes a controller (not shown). Model data for a product is stored in a memory unit of the controller. During additive manufacturing, the controller can control various components based on the stored model data, specifically changing material composition or ratios in real time to collaboratively complete product processing.

[0045] Figure 2 FIG2 is a schematic structural diagram of an additive manufacturing system 20 according to another embodiment of the present disclosure. The additive manufacturing system 20 uses an electric arc as a heat source, and thus may also be referred to herein as an arc additive manufacturing system. Figure 2 Additive Manufacturing System 20 and Figure 1 The same parts of the additive manufacturing system 10 are represented by the same reference numerals, and their detailed description is omitted. Figure 2 Additive Manufacturing System 20 and Figure 1 10 different parts of an additive manufacturing system.

[0046] Figure 2 Additive Manufacturing System 20 and Figure 1 The additive manufacturing system 10 differs in that the arc is used as the heat source, the orientation of the nozzle, and the shape of the inner wall of the nozzle. Figure 2 The additive manufacturing system 20 includes an electric welder 230 and a nozzle 220. The electric welder 230 may be, for example, a tungsten inert gas welding machine. The nozzle 220 has a generally cylindrical inner wall 224, and an electrode of the electric welder 230 is accommodated in the interior space of the inner wall 224. The additive manufacturing system 20 may further include a shielding gas supply device (not shown) to supply shielding gas PG into the interior space of the inner wall 224. For example, the shielding gas may flow through the nozzle 220 at a rate of 5 ml / min to 300 ml / min, optionally 5 ml / min to 200 ml / min.

[0047] Figure 1 The nozzle 120 of the additive manufacturing system 10 is positioned so that the laser beam 134 is substantially perpendicular to the material layer ML, and Figure 2 The nozzle 220 of the additive manufacturing system 20 is positioned at an acute angle relative to the material layer ML. This angled arrangement facilitates arc formation at the tungsten electrode while preventing excessive burns of the tungsten electrode and the nozzle. It should be understood that the nozzle orientation may vary depending on the specific additive manufacturing method.

[0048] Figure 2 The additive manufacturing system 20 has Figure 1 Furthermore, it should be understood that the present invention is not limited to additive manufacturing systems using lasers and arcs as heat sources, but can be applied to additive manufacturing systems using any suitable heat source.

[0049] See below. Figure 3 To describe the additive manufacturing method implemented by the additive manufacturing system according to the present application. Figure 3As shown, the model data and / or control parameters of the product to be manufactured are first stored or loaded into the storage unit of the controller (step S10). Step S10 can be performed before the material is transported from the material source to control the material delivery amount and delivery speed according to the loaded data. Start the heater H2 to preheat the substrate S (step S20). Various materials are transported via the delivery pipes PF1 to PF6 and mixed in the mixer 110 to form the required mixed material (step S30). Start the heater H1 to heat the mixed material supplied via the supply pipe 112 (step S40), for example, to 50°C to 250°C. In the case where the heat source is an electric welder, turn on the shielding gas device to allow the shielding gas to pass through the nozzle at a certain rate (step S50). Start the heat source (for example, the laser 130 or the electric welder 230) to perform additive manufacturing (step S60). The parameters of the heat source (for example, for lasers, these parameters include laser power, spot size, scanning speed, etc.) can be pre-set according to the stored product model data, or can be adjusted in real time according to the model data. During additive manufacturing, the material or its supply amount is adjusted in real time according to the model data to produce the required functional gradient high entropy alloy product (step S70). After the additive manufacturing is completed, the material delivery and supply can be stopped, and the heat source, protective gas device and heating device can be turned off. The heater H2 can be turned off when the temperature of the substrate S drops below 100°C, thereby reducing the stress deformation of the high entropy alloy product.

[0050] Figure 3 Only one example of the additive manufacturing method according to the present application is shown. It should be understood that the present invention is not limited to Figure 3 The specific example shown is shown. As long as the method steps are consistent, the order of some steps can be changed, some steps can be omitted, or other steps can be added. For example, heating steps S20 and S40 can be performed continuously throughout the additive manufacturing process, or only intermittently when needed. Depending on the heat source, step S50 of providing a shielding gas can be omitted.

[0051] The controller in the present invention can be implemented as a processor in a computer. The additive manufacturing methods described herein can be implemented by one or more computer programs executed by the computer processor. The computer programs include processor-executable instructions stored on a non-transitory, tangible, computer-readable medium. The computer programs may also include stored data. Non-limiting examples of non-transitory, tangible, computer-readable media include non-volatile memory, magnetic storage devices, and optical storage devices.

[0052] The term computer-readable medium does not include transient electrical or electromagnetic signals propagated through a medium (e.g., on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of non-transitory, tangible computer-readable media are non-volatile memory (e.g., flash memory, erasable programmable read-only memory, or mask read-only memory), volatile memory (e.g., static random access memory circuits or dynamic random access memory), magnetic storage media (e.g., analog or digital magnetic tape or hard drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0053] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the specific embodiments / examples described and shown in detail herein, and that various changes may be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims.

Claims

1. An additive manufacturing system comprising: a plurality of delivery pipes, each of which is connected to a material source; a mixer to which the plurality of conveying pipes are coupled, the mixer being configured to mix different kinds of powder materials supplied along with air flow via the plurality of conveying pipes in real time during additive manufacturing; and a nozzle, the mixer being coupled to the nozzle via a supply pipe, the nozzle being configured to deliver the mixed material to a substrate for additive manufacturing, Each of the plurality of conveying pipes is configured to be able to change the conveying amount or conveying speed of the powder material in real time. The additive manufacturing system further includes a heating device, which includes a first heater. The first heater is arranged on the supply pipeline to heat the supplied mixed material.

2. The additive manufacturing system according to claim 1, wherein: The nozzle has an inner wall and an outer wall, and an annular space is formed between the inner wall and the outer wall to receive the mixed material.

3. The additive manufacturing system according to claim 2, further comprising a laser or arc welding device for melting the mixed material, wherein The inner wall of the nozzle is configured to allow the laser light of the laser or the electrode of the arc welding device to pass therethrough.

4. The additive manufacturing system according to claim 2, wherein: The inner wall and the outer wall of the nozzle are coaxially arranged.

5. The additive manufacturing system according to claim 4, wherein: Each of the inner wall and the outer wall of the nozzle includes a cylindrical section and / or a conical section.

6. The additive manufacturing system according to any one of claims 1 to 5, wherein: The system further comprises a controller, which realizes real-time control of the conveying amount or conveying speed of the powder material in each of the plurality of conveying pipes.

7. The additive manufacturing system according to claim 6, wherein: The heating device further includes a second heater configured to heat the substrate.

8. An additive manufacturing method comprising: Different types of powder materials are transported from a material source to a mixer via a plurality of transport pipes; Mixing the powder materials in real time in the mixer; as well as The mixed material is transported to the substrate through the nozzle along with the air flow for additive manufacturing. Wherein, conveying the powder material through the plurality of conveying pipes includes changing the conveying amount or conveying speed of the powder material in real time, The mixer is connected to the nozzle via a supply pipe, and the additive manufacturing method further includes: heating the supplied mixed material by a first heater provided on the supply pipe.

9. The additive manufacturing method according to claim 8, wherein: The additive manufacturing method further includes a step of loading product manufacturing data and control parameters into a controller before conveying the powder material from the material source, so as to control the conveying amount and conveying speed of the powder material according to the loaded data.

10. The additive manufacturing method according to claim 9, further comprising the step of melting the mixed material by a laser or an arc welding device.

11. The additive manufacturing method according to claim 10, wherein: The additive manufacturing method further includes providing a shielding gas to an electrode of the arc welding device during the process of melting the mixed material by the arc welding device.

12. The additive manufacturing method according to claim 10, wherein: When the mixed material is melted by a laser, the nozzle and the laser beam are perpendicular to the substrate or form a predetermined angle with respect to the substrate, and the mixed material is transported around the laser beam onto the substrate.

13. The additive manufacturing method according to any one of claims 8 to 12, wherein: In the case where the mixed material is melted by an arc welding device, the nozzle and the electrode of the arc welding device are angled with respect to the substrate, and the mixed material is conveyed around the electrode onto the substrate. 14 . The additive manufacturing method according to claim 13 , further comprising heating the substrate by a second heater during the manufacturing process. 15 . A computer-readable medium having a program stored thereon, wherein when the program is executed by a processor of a control unit, the additive manufacturing method according to claim 8 is implemented.

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