Double-sided mirror image laser melting deposition additive manufacturing device and part manufacturing method

Abstract

The invention provides a double-sided mirror image laser melting deposition additive manufacturing device and a part manufacturing method. The device comprises a base plate, a tool clamp, a first laser machining head, a second laser machining head, a first multi-axis mechanical arm, a second multi-axis mechanical arm and a wire feeding mechanism. The substrate is provided with a first processing surface and a second processing surface which are oppositely arranged; the tool clamp is used for clamping and fixing a base plate so that the base plate can be vertically arranged. The wire feeding mechanism is used for conveying an additive manufacturing material; wherein the first laser machining head can conduct melting deposition of additive manufacturing materials on the first machining face along a first additive manufacturing track, meanwhile, the second laser machining head synchronously conducts melting deposition of the additive manufacturing materials on the second machining face along a second additive manufacturing track, and the first additive manufacturing track and the second additive manufacturing track are mirror images of each other. Machining thermal deformation can be avoided as much as possible, and the workpiece precision is improved while a large number of materials are saved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and more specifically, to a double-sided mirror laser melting deposition additive manufacturing device and a parts manufacturing method. Background Art

[0002] The existing integral frame beam parts with reinforcing ribs have complex structural shapes and high precision requirements. The thickness of the reinforcing ribs is generally 3mm-10mm, the precision requirement in the thickness direction reaches ±0.1mm, and the height is 5mm-20mm. Considering the weight reduction design of aircraft, the thickness of the web of the frame beam parts is generally about 3-10mm. Such complex structure frame beam parts have manufacturing difficulties such as large size, weak rigidity and complex shape. Its efficient and low-cost processing technology has always been a hot topic in the manufacturing field. At present, there are two main manufacturing methods for its structure: First, overall forging and then machining. In order to envelop the height of the reinforcing ribs, the blank of the forging has a large margin in the thickness direction. This method has low material utilization (about 5-20%), long processing time and high cost. Second, use the overall vertical single-sided laser powder feeding direct deposition (or other additive manufacturing methods). First, the single-sided laser direct deposition additive manufacturing of the substrate is carried out, and then the overall subtractive manufacturing of the formed parts is carried out. Single-sided laser powder feeding direct deposition additive manufacturing has a large degree of deformation, and a large amount of processing allowance is usually reserved to envelope the deformation, resulting in high material and post-processing costs. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The technical problem to be solved by the present invention is that the existing method for machining parts has a low material utilization rate, and the parts formed by the existing single-sided laser powder feeding direct deposition additive manufacturing method have a large degree of deformation and high material and post-processing costs.

[0005] (II) Technical solution

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

[0007] In the first aspect, the present invention provides a double-sided mirror laser melting deposition additive manufacturing device, comprising a substrate, a fixture, a first laser processing head, a second laser processing head, a first multi-axis robot arm, a second multi-axis robot arm and a wire feeding mechanism; the substrate has a first processing surface and a second processing surface arranged opposite to each other; the fixture is used to clamp and fix the substrate so that the substrate is arranged vertically; the first laser processing head and the second laser processing head are mirror-imaged on opposite sides of the substrate; the first multi-axis robot arm is connected to the first laser processing head, and is used to drive the first laser processing head to move along a preset first additive manufacturing trajectory; the second multi-axis robot arm is connected to the second laser processing head, and is used to drive the second laser processing head to move along a preset second additive manufacturing trajectory; the wire feeding mechanism is used to convey additive manufacturing materials; wherein, the first laser processing head can perform melt deposition of additive manufacturing materials on the first processing surface along the first additive manufacturing trajectory, and at the same time, the second laser processing head synchronously performs melt deposition of additive manufacturing materials on the second processing surface along the second additive manufacturing trajectory, and the first additive manufacturing trajectory and the second additive manufacturing trajectory are mirror images of each other.

[0008] Preferably, the first laser processing head has a wire feeding channel arranged at its center position and an annular laser head surrounding the center position, the wire feeding channel is used for allowing the additive manufacturing material to pass through, and the annular laser head is used to generate an annular laser to act on the additive manufacturing material.

[0009] Preferably, the additive manufacturing material is filament or powder.

[0010] In a second aspect, the present invention further provides a part manufacturing method, which uses the double-sided mirror laser melting deposition additive manufacturing device described in any one of the above technical solutions to prepare a part, and the part manufacturing method comprises the following steps:

[0011] Establishing a digital model of the part according to the shape and size of the part, and slicing the digital model of the part to determine a first additive manufacturing trajectory and a second additive manufacturing trajectory;

[0012] The first multi-axis robotic arm drives the first laser processing head to move along a preset first additive manufacturing trajectory, and the first laser processing head performs melt deposition of additive manufacturing material on the first processing surface along the first additive manufacturing trajectory; at the same time, the second laser processing head synchronously performs melt deposition of additive manufacturing material along the second additive manufacturing trajectory at a mirror image position of the second processing surface, and after the deposition is completed, the part is obtained.

[0013] Preferably, the method further comprises the following steps:

[0014] The part is machined to obtain a part with a preset dimensional accuracy.

[0015] Preferably, the part is a frame beam structure.

[0016] Preferably, the material of the substrate is of the same composition as the additive manufacturing material.

[0017] Preferably, the part is an I-beam structure, the substrate is used to form the web of the I-beam, the first laser processing head melts and deposits the additive manufacturing material to form a flange plate connected to one end of the web, and the second laser processing head melts and deposits the additive manufacturing material to form a flange plate connected to the other end of the web, thereby obtaining an I-beam structure molded part.

[0018] Preferably, the method further comprises the following steps:

[0019] The I-beam structural formed part is machined to obtain an I-beam part with a preset dimensional accuracy.

[0020] (III) Beneficial effects

[0021] The above technical solution of the present invention has at least the following advantages:

[0022] 1. In the present invention, the first multi-axis robot drives the first laser processing head to move along a preset first additive manufacturing trajectory, and the first laser processing head performs melt deposition of additive manufacturing material on the first processing surface along the first additive manufacturing trajectory; at the same time, the second laser processing head synchronously performs melt deposition of additive manufacturing material along the second additive manufacturing trajectory at a mirror image position on the second processing surface. By performing melt deposition of additive manufacturing material synchronously in a mirror image on the first processing surface and the second processing surface that are relatively arranged on the substrate, thermal deformation during processing can be avoided as much as possible, thereby saving a large amount of material and improving the workpiece accuracy.

[0023] 2. In the present invention, for frame beam structures such as I-beams, by combining partial structures of the parts with the shape and size of the substrate and rationally designing the structural parts that require additive manufacturing, it is possible to reduce stress concentration caused by the shape forming of the structure itself, thereby improving the strength of the final formed structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a schematic structural diagram of a double-sided mirror laser melting deposition additive manufacturing device provided in an embodiment of the present invention.

[0026] Figure 2It is a partial enlarged view of the first laser processing head and the second laser processing head provided in an embodiment of the present invention.

[0027] Figure 3 It is a schematic diagram of the structure of a part after molding provided by an embodiment of the present invention.

[0028] Figure 4 It is a forming flow chart of the I-beam structure provided by an embodiment of the present invention.

[0029] The reference numerals in the figures are:

[0030] 1. Substrate; 2. Fixture; 3. First laser processing head; 4. Second laser processing head; 5. First multi-axis robot arm; 6. Second multi-axis robot arm; 11. First processing surface; 12. Second processing surface; 21. Fixture base; 22. Clamping part; 31. Wire feeding channel; 32. Ring laser head. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0035] like Figure 1As shown, an embodiment of the present invention provides a double-sided mirror laser melting deposition additive manufacturing device, including a substrate 1, a fixture 2, a first laser processing head 3, a second laser processing head 4, a first multi-axis robot 5, a second multi-axis robot 6 and a wire feeding mechanism (not shown); the substrate 1 has a first processing surface 11 and a second processing surface 12 arranged opposite to each other; the fixture 2 is used to clamp and fix the substrate 1 so that the substrate 1 is arranged vertically; the first laser processing head 3 and the second laser processing head 4 are mirror-imaged on opposite sides of the substrate 1; the first multi-axis robot 5 is connected to the first laser processing head 3, and is used to drive the first laser processing head 3 to move along a preset first additive manufacturing trajectory; the second multi-axis robot 6 is connected to the second laser processing head 4, and is used to drive the second laser processing head 4 to move along a preset second additive manufacturing trajectory; the first multi-axis robot 5 and the second multi-axis robot 6 with multiple degrees of freedom are used to provide redundant degrees of freedom to achieve diversity in the posture position of the robot end, so as to compensate for the gravity of the molten pool. The wire feeding mechanism is used to transport additive manufacturing materials; wherein the first laser processing head 3 can melt and deposit additive manufacturing materials along the first additive manufacturing trajectory on the first processing surface 11, and at the same time, the second laser processing head 4 synchronously melts and deposits additive manufacturing materials along the second additive manufacturing trajectory on the second processing surface 12, and the first additive manufacturing trajectory and the second additive manufacturing trajectory are mirror images of each other. Specifically, there are two wire feeding mechanisms, one of which is used to continuously transport additive manufacturing materials along the first additive manufacturing trajectory, and the other wire feeding mechanism is used to continuously transport additive manufacturing materials along the second additive manufacturing trajectory. The specific structure and working principle of the wire feeding mechanism are prior art well known to those skilled in the art, and will not be described in detail in this application. Specifically, in this embodiment, the laser processing head preferably includes a first laser processing head 3 and a second laser processing head 4. In other embodiments, there may be more than two laser processing heads. Two or an even number of laser melting and deposition coaxial or lateral fuse nozzles are placed horizontally and arranged one by one on both sides of the substrate. The horizontal direction is the material stacking direction, and the two vertical substrate surfaces are stacking surfaces. According to the predetermined slicing program, mirror processing is performed simultaneously to obtain bilaterally symmetrical frame beam parts or two part bodies. This patent can also use high-speed feeding of powder to reduce the powder-light coupling problem in the non-vertical direction.

[0036] In the prior art, the additive manufacturing method for most parts is generally to set the substrate horizontally, and then perform melt deposition additive manufacturing in a direction substantially perpendicular to the substrate, and finally deposit and solidify the additive manufacturing material to form a part of a specific shape. The parts formed by this additive manufacturing method are prone to thermal deformation under the action of welding heat accumulation, and finally the shape and size accuracy of the formed parts are reduced. In this embodiment, by setting the substrate vertically, mirroring and synchronously moving on two relatively set processing surfaces (i.e., the first processing surface 11 and the second processing surface 12), and performing melt deposition on the two relatively set processing surfaces at the same time, the thermal deformation of the final formed parts can be effectively reduced, thereby improving the forming accuracy of the parts. In this way, low deformation, high-precision printing, high material utilization, and low-cost manufacturing of the reinforcement ribs or the body of the frame beam parts can be achieved. In the present invention, according to the appearance characteristics of the overall frame beam structure, the substrate or the part body that needs to be deposited with reinforcement ribs can be placed vertically, and the first laser processing head 3 and the second laser processing head 4 can be arranged on both sides. The working mode of double-sided mirror deposition is adopted to perform horizontal additive manufacturing on the vertical plane. The reinforcement rib body can be deposited by double-sided mirror deposition, and the part body can also be deposited by double-sided mirror deposition. The deposition substrate can use a plate or forging with the same composition as the additive manufacturing material, or a supporting skeleton formed by direct laser deposition. The substrate can be retained in the mixed manufacturing inside the final part, or it can be all a supporting skeleton formed by direct laser deposition + double-sided mirror deposition. It is intended to reduce the forming deformation error and improve the material utilization rate by using the double-sided mirror additive manufacturing method.

[0037] In this embodiment, the first laser processing head 3 and the second laser processing head 4 move synchronously and in mirror image on the first processing surface and the second processing surface.

[0038] like Figure 2 As shown, in one embodiment, the first laser processing head 3 has a wire feeding channel 31 arranged at its center and a ring laser head 32 surrounding the center, the wire feeding channel 31 is used for the additive manufacturing material to pass through, and the ring laser head 32 is used to generate a ring laser to act on the additive manufacturing material. Specifically, the wire feeding channel 31 is arranged at the center of the first laser processing head 3, which helps to achieve coaxial wire feeding and control the accuracy of wire feeding. Furthermore, the specific structure of the second laser processing head 4 is the same as that of the first laser processing head 3.

[0039] In one embodiment, the additive manufacturing material is a wire or powder. In this embodiment, the additive manufacturing material is preferably a wire, because the wire itself has a certain material rigidity, and during the additive manufacturing process, the wire is not easily changed in position by external forces, which helps to control the part forming accuracy during the additive manufacturing process.

[0040] The present invention also provides a part manufacturing method, which uses any of the double-sided mirror laser melting deposition additive manufacturing devices in the above embodiments to prepare the part, and the part manufacturing method includes the following steps:

[0041] Establishing a digital model of the part according to the shape and size of the part, and slicing the digital model of the part to determine a first additive manufacturing trajectory and a second additive manufacturing trajectory;

[0042] The first multi-axis robot 5 drives the first laser processing head 3 to move along the preset first additive manufacturing trajectory, and the first laser processing head 3 performs melt deposition of additive manufacturing materials on the first processing surface 11 along the first additive manufacturing trajectory; at the same time, the second laser processing head 4 synchronously performs melt deposition of additive manufacturing materials along the second additive manufacturing trajectory at the mirror position of the second processing surface 12, and after the deposition is completed, a part is obtained. Figure 3 As shown, the first laser processing head 3 performs additive manufacturing on the first processing surface 11 of the substrate 1 to form a first additive region 101 , and the second laser processing head 4 performs additive manufacturing on the second processing surface 12 of the substrate 1 to form a second additive region 102 .

[0043] In one embodiment, the following steps are also included:

[0044] like Figure 3 As shown, according to the preset size of the part, the part after additive manufacturing is machined to remove the substrate material removal part 13 and the additive manufacturing material removal part 103 to form a part with preset dimensional accuracy, and finally achieve high-precision preparation of the part. The part is machined to obtain a part with preset dimensional accuracy. The machined workpiece is post-processed to remove part of the substrate and part of the laser melting deposition additive manufacturing layer to reduce the processing stress during the additive manufacturing process.

[0045] In one embodiment, the component is a frame beam structure.

[0046] In one embodiment, the material of the substrate 1 is the same as the composition of the additive manufacturing material.

[0047] In one embodiment, the part is an I-beam structure, the substrate is used to form the web of the I-beam, the first laser processing head 3 melts and deposits the additive manufacturing material to form a flange plate connected to one end of the web (i.e., the first structure 104), and the second laser processing head 4 melts and deposits the additive manufacturing material to form a flange plate connected to the other end of the web (i.e., the second structure 105), thereby obtaining an I-beam structure molded part. Specifically, as Figure 4As shown, when designing the I-beam structure, the web part of the I-beam structure is designed inside the substrate 1. In this embodiment, preferably, the thickness of the substrate 1 is equal to the web thickness of the I-beam structure. Then, the flange plates of the I-beam structure are formed by additive manufacturing on both sides of the substrate 1. The I-beam structure formed by this method can reduce the thermal deformation of the final formed I-beam structure because the forming process on both sides is mirrored. Moreover, compared with the I-beam structure formed by machining or additive manufacturing in the prior art, the I-beam structure formed by this embodiment effectively solves the problem of stress concentration at the root of the I-beam structure, thereby effectively improving the stress concentration problem of the parts after forming. In addition, compared with the method of forming entirely by additive manufacturing in the prior art, this embodiment does not need to use other tooling to support the parts in the forming process, which effectively reduces the complexity of the process.

[0048] In one embodiment, the following steps are also included:

[0049] Machining of I-beam structural parts to obtain I-beam parts with preset dimensional accuracy.

[0050] Specifically, the part manufacturing method provided in this embodiment can be used to manufacture a single part with a symmetrical structure, or can be used to manufacture two parts with the same structure. When used to manufacture two parts with the same structure, after additive manufacturing is completed, the additive molded part can be cut into two parts along the thickness center line of the substrate by wire cutting.

[0051] like Figure 1 The specific implementation steps of this embodiment are as follows:

[0052] The substrate 1 is placed vertically on the tooling base 21 , and the substrate 1 is fixed by a clamping member 22 .

[0053] The first laser processing head 3, the second laser processing head 4, the first multi-axis robot arm 5 and the second multi-axis robot arm 6 are leveled to the initial positions so as to perform the subsequent printing process.

[0054] The additive manufacturing material is loaded into the first laser processing head 3 and the second laser processing head 4 for preparation.

[0055] The part of the part that needs additive manufacturing is sliced ​​and modeled, and the additive manufacturing path (i.e., the first additive manufacturing trajectory and the second additive manufacturing trajectory) is programmed. Specifically, according to the shape characteristics of the part, the additive manufacturing path planning is divided into the following two categories:

[0056] (1) If the left and right processing areas of the reinforcing ribs are arranged completely symmetrically, the double-sided mirror laser melting deposition additive manufacturing adopts a mirror processing method, that is, feeding is performed simultaneously on the first processing surface 11 and the second processing surface 12.

[0057] (2) If the left and right processing areas of the reinforcing ribs are not arranged completely symmetrically, the digital model is firstly symmetrically compensated for the asymmetric area, and then the double-sided mirror laser melting deposition additive manufacturing adopts a mirror processing method, that is, the first processing surface 11 and the second processing surface 12 are fed simultaneously. Then, the material in the asymmetric area is removed by the subtractive manufacturing process.

[0058] According to the preset first additive manufacturing trajectory and the second additive manufacturing trajectory, double-sided mirror laser melting deposition additive manufacturing is performed on both sides of the substrate to obtain the formed parts.

[0059] Remove the part from fixture 2 to complete the operation.

[0060] Specifically, for easily oxidizable materials such as titanium alloys, the device must always be kept in an inert atmosphere before and after working to avoid oxidation during material printing.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-sided mirror laser melting deposition additive manufacturing device, characterized in that: include: A substrate having a first processing surface and a second processing surface arranged opposite to each other; A fixture, used for clamping and fixing the substrate so that the substrate is arranged vertically; A first laser processing head and a second laser processing head, wherein the first laser processing head and the second laser processing head are mirror-imaged and arranged on opposite sides of the substrate; A first multi-axis robot arm, connected to the first laser processing head, and used to drive the first laser processing head to move along a preset first additive manufacturing trajectory; A second multi-axis robot arm, connected to the second laser processing head, and used to drive the second laser processing head to move along a preset second additive manufacturing trajectory; A wire feeding mechanism for conveying additive manufacturing materials; The first laser processing head is capable of performing melt deposition of additive manufacturing material on the first processing surface along the first additive manufacturing trajectory, and the second laser processing head is synchronously performing melt deposition of additive manufacturing material on the second processing surface along the second additive manufacturing trajectory, and the first additive manufacturing trajectory and the second additive manufacturing trajectory are mirror images of each other.

2. The double-sided mirror laser melting deposition additive manufacturing device according to claim 1, characterized in that: The first laser processing head has a wire feeding channel arranged at its center position and an annular laser head surrounding the center position, the wire feeding channel is used for allowing the additive manufacturing material to pass through, and the annular laser head is used for generating an annular laser to act on the additive manufacturing material.

3. The double-sided mirror laser melting deposition additive manufacturing device according to claim 1, characterized in that: The additive manufacturing material is a wire or powder.

4. A parts manufacturing method, characterized in that: A part is prepared by using a double-sided mirror laser melting deposition additive manufacturing device as described in any one of claims 1 to 3, and the part manufacturing method comprises the following steps: Establishing a digital model of the part according to the shape and size of the part, and slicing the digital model of the part to determine a first additive manufacturing trajectory and a second additive manufacturing trajectory; The first multi-axis robotic arm drives the first laser processing head to move along a preset first additive manufacturing trajectory, and the first laser processing head performs melt deposition of additive manufacturing material on the first processing surface along the first additive manufacturing trajectory; at the same time, the second laser processing head synchronously performs melt deposition of additive manufacturing material along the second additive manufacturing trajectory at a mirror image position of the second processing surface, and after the deposition is completed, the part is obtained.

5. The parts manufacturing method according to claim 4, characterized in that: The following steps are also included: The part is machined to obtain a part with a preset dimensional accuracy.

6. The parts manufacturing method according to claim 4, characterized in that: The part is a frame beam structure.

7. The parts manufacturing method according to claim 4, characterized in that: The material of the substrate is the same as the composition of the additive manufacturing material.

8. The parts manufacturing method according to claim 4, characterized in that: The part is an I-beam structure, the substrate is used to form the web of the I-beam, the first laser processing head melts and deposits the additive manufacturing material to form a flange plate connected to one end of the web, and the second laser processing head melts and deposits the additive manufacturing material to form a flange plate connected to the other end of the web, thereby obtaining an I-beam structure formed part.

9. The parts manufacturing method according to claim 8, characterized in that: The following steps are also included: The I-beam structural formed part is machined to obtain an I-beam part with a preset dimensional accuracy.

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