A method and apparatus for induction heating-assisted stirring friction additive manufacturing

Abstract

This invention provides an induction heating-assisted friction stir additive manufacturing method and apparatus, belonging to the field of metal additive manufacturing technology. The method includes: preparing an additive layer using a hollow rotating shoulder with several arc-shaped grooves on its bottom end face, the arc-shaped grooves gradually opening from the center to the outer edge of the end face and closing at both ends; an induction heater is disposed on the rotating shoulder, the induction heater including a U-shaped induction heating coil and a power connection and mounting part, the U-shaped induction heating coil being suspended below the rotating shoulder, the two sides of the U-shaped induction heating coil being parallel to a preset additive direction; a high-frequency current is passed into the induction heater, and the U-shaped induction heating coil heats the outer edges of the additive layer on both sides through the two sides. The technical solution of this invention solves the problems of poor edge bonding, large flash, and poor forming quality in existing friction stir additive manufacturing of copper alloys and high-melting-point metals.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal additive manufacturing, in particular, especially relates to an induction heating assisted friction stir additive method and device. BACKGROUND

[0002] Friction stir solid deposition technology is an advanced solid additive technology developed in recent years. Compared with other additive methods based on local melting such as laser and electric arc, it has unique technical advantages. For example, for aluminum alloy, magnesium alloy and other materials, using local melting additive method, it is easy to produce porosity, hot cracking and other metallurgical problems, and the performance of additive layer is not high; for high nitrogen steel, OSD steel and other special steel, using local melting additive method, it is easy to produce porosity and reinforcement phase particle aggregation and other problems. In view of this, based on friction stir welding and processing technology, a new friction stir solid additive technology is developed. This technology uses a consumable additive rod to form continuous deposition layer through rotary friction softening and shoulder extrusion, effectively solving various metallurgical problems existing in the above local melting additive method. At the same time, due to the dynamic recrystallization and dynamic precipitation of additive layer, the performance of additive layer is significantly improved.

[0003] So far, the friction stir solid additive technology for low melting point alloy has been relatively mature. In contrast, although the friction stir solid additive process verification of copper alloy and high melting point metal has been realized, it has not been applied in practice, the main problems are: (1) due to the sharp drop of the edge temperature of the additive layer, the metal fluidity becomes poor, which causes the edge part of the layer to be difficult to effectively combine with each other; (2) obvious sawtooth burrs appear at the edge of the additive layer, which increases the subsequent processing cost.

[0004] Patent CN221560111U proposes a resistance heating and temperature measuring device for friction stir additive manufacturing, which preheats by providing resistance heat through current flowing in the additive rod, the purpose is to reduce the extrusion on the additive layer, but it cannot solve the problem of poor quality of the edge of the additive layer, especially, this method needs complex circuit and insulation design, which is difficult to be applied in practice. Patent CN214978474U proposes an auxiliary heating and chilling combined friction stir additive device, which designs a large induction heating coil to heat and extremely cool the outer edge of the additive block material in a limited area, but the induction coil in this device cannot move horizontally with the main shaft, so it still cannot solve the problem of poor quality of the edge of each layer.

[0005] Therefore, it is urgent to find a solution to improve the quality of copper alloy and high melting point metal friction stir additive, and promote the practical application of the technology. SUMMARY

[0006] In order to solve the problems of the existing copper alloy and high melting point metal, such as the poor edge combination between the friction stir additive layers, the large flash and the poor forming quality, the application provides an induction heating assisted friction stir additive method and device, by adopting a rotating shoulder with a spiral groove on the bottom end face, cooperating with the induction heating around the outside of the additive layer, enhancing the interface metallurgical bonding, controlling the flash formation, and further improving the friction stir additive efficiency and quality.

[0007] The technical means adopted by the application are as follows:

[0008] An induction heating assisted friction stir additive method, specifically comprising: preparing an additive layer by adopting a rotating shoulder with a hollow and a plurality of arc-shaped grooves on the bottom end face, the arc-shaped grooves are gradually opened from the center to the outer edge of the end face and are closed at both ends; an induction heater is arranged on the rotating shoulder, the induction heater comprises a U-shaped induction heating coil and a power connection and mounting part, the power connection and mounting part is mounted on the fixed sleeve outside the rotating shoulder to suspend the U-shaped induction heating coil below the rotating shoulder, and the two sides of the U-shaped induction heating coil are parallel to the preset additive direction; the additive rod is placed in the center hole of the rotating shoulder, and in the process of preparing the additive layer on the substrate by adopting the rotating shoulder, the induction heater moves synchronously along the additive direction with the rotating shoulder, high-frequency current is input into the induction heater, and the U-shaped induction heating coil heats the outer edges of the two sides of the additive layer through the two sides.

[0009] Further, a plurality of arc-shaped grooves are equidistantly arranged on the bottom end face of the rotating shoulder in the circumferential direction.

[0010] Further, the power connection and mounting part of the induction heater connects the high-frequency current power source and the U-shaped induction heating coil through the terminal post, and the high-frequency current is input into the U-shaped induction heating coil through the high-frequency current power source.

[0011] Further, the distance between the two sides of the U-shaped induction heating coil is greater than the width of the additive layer.

[0012] Further, the plane where the U-shaped induction heating coil is located is parallel to the upper surface of the substrate, the cross section of the U-shaped induction heating coil is square, and the thickness is equivalent to the thickness of the additive layer.

[0013] Further, in the process of preparing the additive layer on the substrate by adopting the rotating shoulder, the distance between the side of the U-shaped induction heating coil and the outer edge of the additive layer is kept at 2mm to 3mm.

[0014] This invention also provides an induction heating assisted stirring friction additive manufacturing device, including a rotating shoulder, a fixed sleeve, an induction heater, a connecting rod, and a high-frequency current power supply; the rotating shoulder has a central hole for mounting the additive rod along its axial direction, and the bottom end face of the rotating shoulder is provided with several arc-shaped grooves, which gradually open from the center to the outer edge of the end face and are closed at both ends; the fixed sleeve is fixedly sleeved on the rotating shoulder, and a mounting platform is provided on its side; the mounting platform has a mounting hole in the vertical direction, and a threaded hole communicating with the mounting hole is provided on its side; the induction heater includes a U-shaped induction heating coil and a power connection and mounting part; the connecting rod... The bottom is fixedly connected to the power supply connection and mounting part, and the top passes through the mounting hole and is fixed by a fixing bolt threaded into the threaded hole, so that the U-shaped induction heating coil is suspended below the rotating shoulder. The two sides of the U-shaped induction heating coil are parallel to the preset additive direction. The power supply connection and mounting part connects the high-frequency current power supply and the U-shaped induction heating coil through the terminal block. The high-frequency current power supply is used to supply high-frequency current to the U-shaped induction heating coil. The U-shaped induction heating coil is used to heat the outer edges of the two sides of the additive layer during the process of preparing the additive layer on the substrate using the rotating shoulder.

[0015] Furthermore, the levitation height of the U-shaped induction heating coil is adjusted by fixing the connecting rod extending out of the mounting hole by the fixing bolt, so that the levitation height is equivalent to the set additive layer thickness, and the two sides of the U-shaped induction heating coil are located on the outer side of the additive layer.

[0016] Furthermore, the U-shaped induction heating coil is made of copper alloy and has an aluminum oxide coating on its surface.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The induction heating-assisted stirring friction additive manufacturing method and apparatus provided by the present invention utilizes a rotating shoulder with an arc-shaped groove on the bottom end face that is gradually opening and closed at both ends, in conjunction with an induction heater, to improve the temperature and flow capacity of the metal at the edge of the additive layer, eliminate the problem of weak interface connection at the edge of the additive layer, reduce the amount of sawtooth flash and subsequent trimming cutting, and improve additive manufacturing efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the induction heating assisted stirring friction additive manufacturing device of the present invention.

[0021] Figure 2 This is a schematic diagram of the bottom end face structure of the rotating shoulder described in this invention.

[0022] Figure 3 This is a schematic diagram of the side structure of the fixed sleeve described in this invention.

[0023] Figure 4 This is a schematic diagram of the U-shaped induction heating coil structure described in this invention.

[0024] Figure 5 The image shows the morphology of the additive layer obtained using the induction heating-assisted stirring friction additive method and apparatus described in this invention.

[0025] In the diagram: 1. Additive rod; 2. Rotating shoulder; 3. Fixing sleeve; 4. Substrate; 5. Additive layer; 6. U-shaped induction heating coil; 7. Connecting rod; 8. Fixing bolt; 9. Terminal block; 10. High-frequency current power supply. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0030] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0031] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0033] like Figures 1 to 4As shown, this embodiment provides an induction heating assisted stirring friction additive manufacturing device, including a rotating shoulder 2, a fixed sleeve 3, an induction heater, a connecting rod 7, and a high-frequency current power supply 10; the rotating shoulder 2 has a central hole for mounting the additive rod 1 along its axial direction, and the bottom end face of the rotating shoulder 2 is provided with several arc-shaped grooves, which gradually open from the center to the outer edge of the end face and are closed at both ends; the fixed sleeve 3 is fixedly sleeved on the rotating shoulder 2, and a mounting platform is provided on its side; the mounting platform has a mounting hole in the vertical direction, and a threaded hole communicating with the mounting hole is provided on its side; the induction heater includes a U-shaped induction heating coil 6 and a power connection and mounting part; the connecting rod 7 The bottom is fixedly connected to the power supply connection and mounting part, and the top passes through the mounting hole and is fixed by the fixing bolt 8 threaded into the threaded hole, so that the U-shaped induction heating coil 6 is suspended below the rotating shoulder 2. The two sides of the U-shaped induction heating coil 6 are parallel to the preset additive direction. The power supply connection and mounting part connects the high-frequency current power supply 10 and the U-shaped induction heating coil 6 through the terminal 9. The high-frequency current power supply 10 is used to supply high-frequency current to the U-shaped induction heating coil 6. The U-shaped induction heating coil 6 is used to heat the outer edges of the two sides of the additive layer 5 through the two sides during the process of preparing the additive layer 5 on the substrate 4 using the rotating shoulder 2.

[0034] Furthermore, the suspension height of the U-shaped induction heating coil 6 is adjusted by fixing the length of the connecting rod 7 extending out of the mounting hole by the fixing bolt 8, so that the suspension height is equivalent to the set thickness of the additive layer 5, thereby ensuring that the two sides of the U-shaped induction heating coil 6 are located on the outside of the additive layer 5.

[0035] Furthermore, the U-shaped induction heating coil 6 is made of copper alloy and has an aluminum oxide coating on its surface.

[0036] This embodiment provides a method for induction heating assisted stirring friction additive manufacturing using the induction heating assisted stirring friction additive manufacturing device described in the above embodiment, specifically including: (1) preparing an additive layer 5 using a hollow rotating shoulder 2 with several arc-shaped grooves on the bottom end face, the arc-shaped grooves gradually opening from the center to the outer edge of the end face and being closed at both ends; (2) providing an induction heater on the rotating shoulder 2, the induction heater including a U-shaped induction heating coil 6 and a power connection and mounting part, the power connection and mounting part being mounted on a fixed sleeve 3 outside the rotating shoulder 2 so that the U-shaped induction heating coil 6 is suspended below the rotating shoulder 2, the U-shaped induction heating coil 6... The two sides of the heating coil 6 should be parallel to the preset additive direction; (3) The additive rod 1 is placed into the center hole of the rotating shoulder 2, and the stirring head is controlled to drive the rotating shoulder 2 connected to the stirring head to rotate and move on the substrate 4 along the preset additive direction. The additive rod 1 rotates under the drive of the rotating shoulder 2 and feeds downward along the axial direction to prepare the additive layer 5 on the substrate 4. During the process of preparing the additive layer 5 on the substrate 4 using the rotating shoulder 2, the induction heater moves synchronously with the rotating shoulder 2 along the additive direction and a high frequency current is passed into the induction heater. The U-shaped induction heating coil 6 heats the outer edges of the two sides of the additive layer 5 through the two sides.

[0037] Furthermore, the bottom end face of the rotating shoulder 2 is provided with several arc-shaped grooves at equal intervals along the circumference. Preferably, the bottom end face of the rotating shoulder 2 is provided with 3-6 arc-shaped grooves at equal intervals along the circumference, and the depth of the arc-shaped grooves is 0.5mm.

[0038] Furthermore, the power supply connection and mounting part of the induction heater is connected to the high-frequency current power supply 10 and the U-shaped induction heating coil 6 through the terminal 9, and the high-frequency current power supply 10 supplies high-frequency current to the U-shaped induction heating coil 6.

[0039] Furthermore, the distance between the two sides of the U-shaped induction heating coil 6 is greater than that of the additive layer 5.

[0040] Furthermore, the plane containing the U-shaped induction heating coil 6 is parallel to the upper surface of the substrate 4, and the cross-section of the U-shaped induction heating coil 6 is square, with a thickness comparable to that of the additive layer 5.

[0041] Furthermore, during the process of fabricating the additive layer 5 on the substrate 4 using the rotating shoulder 2, the distance between the side of the U-shaped induction heating coil 6 and the outer edge of the additive layer 5 is maintained at 2 mm to 3 mm.

[0042] Figure 5 The image shows the morphology of the additive layer obtained by the induction heating assisted stirring friction additive method and apparatus described in this invention. It can be seen that the metallographic structure and interface bonding after additive manufacturing are well observed. The metal flow from the center to the edge of the additive layer is sufficiently uniform, and the interface bonding is good.

[0043] In existing technologies, induction heating devices assisted in friction stir processing are typically used to heat rods or stirring components, resulting in indirect heating for the additive layer. However, the above embodiment applies this technology to the field of metal friction stir additive manufacturing to improve the edge quality of the additive layer. By synchronously moving the induction heater with the rotating shoulder, the induction heating coil can directly and synchronously heat the outer edge of the additive layer during its fabrication. This, combined with the improved stirring shoulder, improves the edge forming quality of the additive layer. In the above embodiment, the bottom end face of the rotating shoulder is designed with multiple involute arc-shaped grooves, closed at both ends. During additive layer fabrication, the raw material can be embedded in the arc-shaped grooves. The metal within these grooves increases the contact area between the rotating shoulder and the additive layer, and also generates greater friction at the edge of the additive layer through friction between homogeneous materials. Combined with the auxiliary induction heater heating the outer edge of the additive layer, this increases the temperature and fluidity of the outer edge, thereby eliminating weak interface connections and jagged flash, improving the edge forming quality of the additive layer, reducing subsequent trimming, and increasing additive manufacturing efficiency. The friction stir additive manufacturing tool disclosed in patent CN115383279B breaks up edge flash through a radial groove at the bottom of the stirring shoulder. However, this groove is open at both ends and is not suitable for friction stir additive manufacturing of copper alloys and high-melting-point metals. During the preparation of the additive layer, this groove becomes a channel for the metal material to flow to the edge, which is not conducive to the forming control of the additive layer edge. In the above embodiment, the groove at the bottom of the rotating shoulder is not for controlling the edge forming by breaking up the edge flash of the additive layer. Instead, the groove at the bottom of the rotating shoulder is designed as an involute arc groove with closed ends. This groove cannot break up the edge flash of the additive layer, but can ensure that the raw material can be embedded in the arc groove and form "adhesive friction between the same material" with the additive layer during the preparation of the additive layer. This, in conjunction with the induction heater, improves the edge quality of the additive layer.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An induction heating assisted friction stir additive manufacturing method, characterized by, Specifically comprising: The rotating shaft shoulder is provided with a plurality of arc-shaped grooves on the bottom end face, and the arc-shaped grooves are gradually opened from the center to the outer edge of the end face and are closed at both ends. The rotating shaft shoulder is provided with an induction heater, and the induction heater includes a U-shaped induction heating coil and a power connection and mounting part. The power connection and mounting part is mounted on the fixed sleeve outside the rotating shaft shoulder to suspend the U-shaped induction heating coil below the rotating shaft shoulder, and the two sides of the U-shaped induction heating coil are parallel to the preset additive direction. The additive rod is placed in the center hole of the rotating shaft shoulder, and the induction heater moves synchronously along the additive direction during the preparation of the additive layer on the substrate by the rotating shaft shoulder. The plane where the U-shaped induction heating coil is located is parallel to the upper surface of the substrate, the cross section of the U-shaped induction heating coil is square, the thickness is equivalent to the thickness of the additive layer, and the suspension height is equivalent to the set thickness of the additive layer.

2. The induction heating assisted friction stir additive manufacturing method of claim 1, wherein, During the preparation of the additive layer, the raw material can be embedded in the arc-shaped groove, and the metal in the arc-shaped groove can increase the contact area between the rotating shaft shoulder and the additive layer, and can generate greater friction between the homogeneous materials at the edge of the additive layer, which can increase the temperature and fluidity of the outer edge of the additive.

3. The induction heating assisted friction stir additive manufacturing method of claim 1, wherein, The bottom end face of the rotating shaft shoulder is provided with a plurality of arc-shaped grooves at equal intervals in the circumferential direction.

4. The induction heating assisted friction stir additive manufacturing method of claim 1, wherein, The power connection and mounting part of the induction heater connects the high-frequency current power source and the U-shaped induction heating coil through the terminal post, and the high-frequency current power source is connected to the U-shaped induction heating coil.

5. The induction heating assisted friction stir additive manufacturing method of claim 1, wherein, The distance between the two sides of the U-shaped induction heating coil is greater than the width of the additive layer.

6. The induction heating assisted friction stir additive manufacturing method of claim 1, wherein, During the preparation of the additive layer on the substrate by the rotating shaft shoulder, the distance between the side of the U-shaped induction heating coil and the outer edge of the additive layer is kept at 2mm to 3mm. The U-shaped induction heating coil is made of copper alloy material and has an alumina coating on the surface.

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