Method for improving warping angle based on scanning path planning, additive manufacturing method and medium

Abstract

The invention discloses a method for improving a warping angle based on scanning path planning, an additive manufacturing method and a medium. The method comprises the following steps that the thickness h0 of a non-corner area of the additive is determined; the thickness h1 of the corner area of the additive is determined; different scanning strategies are planned based on the thickness h0 and the thickness h1; the deposition process is performed based on different scanning strategies, wherein the number of deposits in the corner region is less than the number of deposits in the non-corner region.

Description

Technical Field

[0001] The present application relates to the relevant technical field of laser direct deposition, more specifically, to a shape control method in a part forming process, and more specifically, to a method for improving the warping angle of additive manufacturing based on scanning path planning, a method for additive manufacturing using the method, and corresponding computer-readable media. The method can be applied to laser direct deposition forming or repairing parts such as front mounting sections and integral blade disks in aircraft engines. Background Art

[0002] In order to reduce the impact on the environment, remanufacturing of high value-added parts has gradually become a mainstream technology. Among the many remanufacturing technologies, laser remanufacturing technology has become an important means of remanufacturing. This is mainly due to the advantages of laser remanufacturing technology with high manufacturing accuracy and good precision. Laser additive remanufacturing (Laser-based remanufacturing) is to add molten material to the worn part area and use a laser energy source to melt the added material.

[0003] Laser Melting Deposition (LMD) technology based on synchronous powder feeding is a common metal additive manufacturing technology. This technology uses a high-energy laser beam to melt the synchronously conveyed metal powder and part of the matrix to form a moving non-steady-state metal molten pool, which is rapidly solidified under an extremely high temperature gradient, deposited point by point, scanned line by line, and accumulated layer by layer to finally form a solid part.

[0004] Compared with traditional repair technologies such as arc welding, the energy density of the high-energy laser beam in this technology is concentrated, the impact on the substrate during the forming process is small, and the forming path is highly flexible. Therefore, it is particularly suitable for the rapid repair of high-value-added parts, such as but not limited to, the installation section system, rear section platform, integral blade disk, turbine blades and other parts in aircraft engines.

[0005] However, during the laser deposition process, the scanning path often has corners, and the angle is generally less than 90°. When the machine tool controls the laser head to move to this area, it often adopts a movement strategy of first decelerating and then accelerating. This is reflected in the laser melting deposition process parameters, that is, the actual scanning rate at this location is less than the theoretical scanning rate. Therefore, during the deposition process, more powder is melted and deposited in this area, resulting in a thicker layer thickness in this area. After the subsequent deposition of multiple layers, this area shows obvious warping, resulting in serious part tolerances and excessive machining allowances.

[0006] At present, in order to solve the phenomenon of slowing down and accelerating the moving speed at the corners, the smooth transition instructions in the machine language or the "Fly-in and Fly-out" method is usually used through interpolation points. The smooth transition instruction scheme can eliminate a certain amount of warping to a certain extent and reduce the height of the warping, but it cannot completely eliminate the warping. In addition, although the "Fly-in and Fly-out" scheme has a good effect in eliminating warping, because it introduces interpolation points, there are a lot of empty paths in the scanning path, and the deposition efficiency will be greatly reduced.

[0007] Therefore, the art is in urgent need of a technical solution that can improve the warping phenomenon during the deposition process without reducing the deposition efficiency. Summary of the invention

[0008] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description given later.

[0009] In order to solve one or more problems in the prior art, this application proposes a method for improving the warping of additive manufacturing. The method is based on the interlayer overlap strategy, which solves the warping problem during the deposition process while having a high deposition efficiency. In addition, the technical solution does not require the purchase of any expensive equipment and supporting advanced software. It can solve the warping problem well only through the planning of the scanning path. The solution is easy to implement, cost-controlled, and highly practical.

[0010] According to a first aspect of the present application, a method for improving the warping of an additive material based on scanning path planning is provided, the method comprising the following steps: determining a thickness h0 of a non-corner region of the additive material; determining a thickness h1 of a corner region of the additive material; and determining a thickness h0 of a non-corner region of the additive material based on the thickness h1. 0 With the thickness h 1 To plan different scanning strategies; based on the different scanning strategies to perform a deposition process, wherein the number of deposition times in the corner area is less than the number of deposition times in the non-corner area.

[0011] According to a preferred embodiment of the present application, based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: if (h 1 -h 0 ) / h 0 =1, then execute strategy S for the next layer 1 , execute strategy S for the next layer 0 , where strategy S0 The scanning path covers the complete path of the corner area and the non-corner area, and the strategy S 1 The scan path only covers the non-corner area.

[0012] According to a preferred embodiment of the present application, based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: if (h 1 -h 0 ) / h 0 >1, then strategy S is executed alternately for subsequent layers 0 and Strategy S 1 , until an even number of layers 2n satisfies: n*(h 1 -2h 0 )=h 0 , then the next 2n+1 layers execute S 0 Strategy, 2n+2 layer execution S 1 Strategy, 2n+3 layer execution S 1 strategy, and then recalculate the number of layers from scratch.

[0013] According to a preferred embodiment of the present application, based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: if (h 1 -h 0 ) / h 0 ≤0.5, then calculate h 0 / (h 1 -h 0 ) and take the integer m of the ratio, and then perform S on the first m layers 0 strategy, followed by a layer of execution S 1 Strategy.

[0014] According to a preferred embodiment of the present application, based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: if 0.5<(h 1 -h 0 ) / h 0 <1, then calculate the integer p such that (p+1)*h 1 =(2p+1)*h 0 , and alternately execute strategy S for subsequent layers 0 and Strategy S 1 , until after the pth alternating cycle, S is executed on the 2p+1 layer 0 Scanning strategy.

[0015] According to a preferred embodiment of the present application, based on the thickness h 0 With the thickness h1 To plan different scanning strategies includes: executing the strategies of S and S' alternately for different sections of each deposition layer and / or for different deposition layers, where the S strategy is that the left scanning path covers the corner region and the right scanning path does not cover the corner region, and where the S' strategy is that the left scanning path does not cover the corner region and the right scanning path covers the corner region.

[0016] According to a preferred embodiment of the present application, based on the thickness h 0 and the thickness h 1 To plan different scanning strategies includes: executing for different sections of each deposition layer and / or for different deposition layers alternately S 2 and S 3 strategies, where S 2 strategy is that the left scanning path only covers the lower corner of the corner region and does not cover the upper corner of the corner region, while the right scanning path only covers the upper corner and does not cover the lower corner, and where S 3 strategy is that the left scanning path only covers the upper corner and does not cover the lower corner, while the right scanning path only covers the lower corner and does not cover the upper corner.

[0017] According to a preferred embodiment of the present application, the strategy of executing a scanning path that does not cover the corresponding region includes: not turning on the light and not feeding powder for the corresponding region.

[0018] According to a preferred embodiment of the present application, different scanning strategies are executed for different sections of the same deposition layer and / or for different deposition layers.

[0019] According to a second aspect of the present application, there is provided an additive manufacturing method, which includes the following steps: removing the damaged area of the additive; performing three-dimensional modeling on the additive; performing scanning path planning by using the method as described above; and repairing the damaged area based on the scanning path planning.

[0020] According to a third aspect of the present application, there is provided a computer-readable medium storing instructions, which when executed by a processor, execute the method as described above.

[0021] To achieve the foregoing and related purposes, these one or more aspects include the features described in detail below and particularly pointed out in the appended claims. The following description and the drawings elaborate certain illustrative features of these one or more aspects. However, these features merely indicate several of the various ways in which the principles of the various aspects can be employed, and this description is intended to cover all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to understand in detail the manner in which the above-stated features of the present application are used, a more specific description of the above briefly summarized contents may be made with reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present application and should not be considered to limit its scope, as the present description may allow for other equally effective aspects.

[0023] In the attached picture:

[0024] Figure 1 is an illustration of S in a first embodiment of the method described herein. 0 With S 1 Schematic diagram of the strategy;

[0025] Figure 2 is a schematic diagram illustrating a situation 1 in a first embodiment according to the method described herein;

[0026] Figure 3 is a schematic diagram illustrating a situation 2 in a first embodiment according to the method described herein;

[0027] Figure 4 is a schematic diagram illustrating situation 3 in a first embodiment according to the method described herein;

[0028] Figure 5 is a schematic diagram illustrating a situation 4 in a first embodiment according to the method described herein;

[0029] Figure 6 is a schematic diagram illustrating the S and S' strategies in a second embodiment according to the method described herein;

[0030] Figure 7 is an illustration of S in the third embodiment of the method described herein. 2 With S 3 Schematic diagram of the strategy;

[0031] Figure 8 is a schematic diagram illustrating additive manufacturing according to the method described herein;

[0032] Fig. 9 is a comparative diagram illustrating the effects of additive manufacturing according to the method described in this article; and

[0033] Fig.10 is a flow chart illustrating a method for improving additive warp based on path planning according to the present invention. DETAILED DESCRIPTION

[0034] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known components are shown in block diagram form in order to avoid diluting such concepts.

[0035] It is to be understood that other embodiments would be apparent based on the present disclosure, and that system, structural, process, or mechanical changes may be made without departing from the scope of the present disclosure.

[0036] In the process of layer-by-layer deposition in additive manufacturing, whenever the scanning path reaches a small-angle corner, the thickness of this area is easily increased due to the acceleration and deceleration during the movement of the machine tool. After multiple layers of deposition, the corner area is prone to excessive accumulation, resulting in warping, which causes serious deviations in the formed parts of additive manufacturing and excessive removal of machining. The present application provides a new solution to warping, which not only has a good warping elimination effect, but also avoids the defect of low deposition efficiency by avoiding a large amount of idle travel.

[0037] Specifically, the present application utilizes the characteristics of thicker layers in the corner area and thinner layers in other areas to plan the scanning path. By overlapping the thicker and thinner layers, the warping of the corners is reduced. At the same time, because no changes are made to the hardware equipment and no advanced software is used to increase the software cost, the overall cost is very low. In addition, the solution of the present application can be used in any programmable laser direct deposition equipment, with a wide range of applications and easy implementation.

[0038] Specifically, the effect of eliminating the warped corners can be achieved by adopting two different strategies, namely, depositing in the corner area or not depositing in the corner area, for different deposition layers and / or different sections of the same deposition layer.

[0039] Figure 1 Schematic diagrams of different scanning strategies according to the solutions of the present application are shown in FIG.

[0040] like Figure 1 As shown in 0 Indicates to perform a full path scan for a layer / segment ( Figure 1 As shown in the left figure); while strategy S 1 Indicates the strategy of not opening the corner area and not sending powder for a certain layer / section. Figure 1 As shown in the figure on the right). Execute S for a certain layer 0 Strategy or S 1 The strategy depends on the thickness h of the non-corner region 0 The thickness of the corner area h1 If the thickness of the corner area is too large, it can be selected to deposit only the non-corner area. Of course, the standard of whether it is too large can be comprehensively judged by technicians in this field according to various conditions such as the size requirements of the actual workpiece, process limitations, etc. These do not limit the scope of protection of this application.

[0041] As a preferred embodiment of the present application, the following is combined Figures 2 to 4 Implement strategies in detail according to different situations that may arise in reality 0 With Strategy S 1 Detailed description.

[0042] Figure 2 Case 1 is shown in FIG.

[0043] If (h 1 -h 0 ) / h 0 =1, that is, when the thickness of the corner area is equal to twice that of the non-corner area, the strategy of not opening the corner area and not feeding powder is adopted when depositing the next layer, that is, strategy S 1 , and then adopt strategy S when depositing the next layer 0 ,like Figure 2 as shown in .

[0044] Figure 3 Case 2 is shown in FIG.

[0045] If (h 1 -h 0 ) / h 0 >1, that is, when the thickness of the corner area is greater than twice that of the non-corner area, S 0 and S 1 The printing method of alternating strategies is used until an even number of layers 2n is reached, satisfying: n*(h 1 -2h 0 )=h 0 , then 2n+1 layer uses S 0 Strategy, 2n+2 layers use S 1 Strategy, 2n+3 layers use S 1 strategy, and then recalculate the number of layers from scratch, such as Figure 3 as shown in .

[0046] Of course, as those skilled in the art can understand, the equality relationship between the two is not absolute, and the error can be fully determined by their comprehensive judgment in the actual processing process. As long as the two basically satisfy the above relationship, deposition can be performed according to the above path planning.

[0047] Figure 4 Case 3 is shown in FIG.

[0048] If (h1 -h 0 ) / h 0 ≤0.5, then calculate h 0 / (h 1 -h 0 ) and take the integer m of the ratio, and then use the first m layers S 0 Scanning strategy, the next layer uses S 1 Scanning strategies, such as Figure 4 as shown in .

[0049] Figure 5 Case 4 is shown in FIG.

[0050] If 0.5<(h 1 -h 0 ) / h 0 <1, then calculate the integer n such that (n+1)*h 1 =(2n+1)*h 0 , and adopt S 0 and S 1 The strategy of alternating until the nth alternating cycle, S is used in the 2n+1 layer 0 Scanning strategy. Similarly, as those skilled in the art can appreciate, the equality relationship between the two is not absolute, it can be an approximately equal relationship, and the error between them can be comprehensively judged by those skilled in the art in the actual processing process. As long as the two basically satisfy the above relationship, deposition can be performed according to the above path planning.

[0051] As another preferred embodiment of the present application, for the same layer, a segmented scanning strategy can be adopted, for example, only a single track is taken at a corner, and different scanning strategies are adopted for odd and even layers.

[0052] Figure 6 A detailed schematic diagram of Case 5 is shown in FIG.

[0053] For case 5, each layer is scanned in sections, and different layers are scanned alternately. Figure 6 The strategy of S and S' shown in .

[0054] The S strategy is: the R-side scanning path covers the corners, as shown in the dotted circle in the left figure, and the L-side scanning path does not cover the circle area;

[0055] The S' strategy is opposite to the S strategy, that is, the L-side scanning path covers the corner, as shown in the dotted circle in the right figure, while the R-side scanning path does not cover the circle area.

[0056] Figure 7 A detailed schematic diagram of Case 6 is shown in FIG.

[0057] For case 6, each layer is also scanned in sections, and the same layer is scanned alternately. Figure 7 The S shown in 2 With S 3 strategy.

[0058] S 2 The strategy is that the scanning path on the L side only covers the lower corner circle area, but not the upper corner circle area, and the scanning path on the R side only covers the upper corner circle area, but not the lower corner circle area. As shown in the circles in the left figure.

[0059] S 3 Strategy and S 2 On the contrary, on the L side, the scanning path only covers the upper corner circle, but not the lower corner area, while on the R side, the scanning path only covers the lower corner area, but not the upper corner area, as shown in the circle in the right figure.

[0060] By adopting different scanning strategies for different deposition layers and / or executing different scanning strategies for different sections of the same deposition layer, the solution of the present application does not require any hardware changes or new scanning software. It only needs to change the scanning path to overcome the problem of warping at the corners, and will not cause a decrease in deposition efficiency. Of course, as those skilled in the art can appreciate, in actual operation, different strategies can be executed simultaneously for different deposition layers and different sections of the same deposition layer, which are all completely within the scope of protection of the present application.

[0061] The specific implementation and beneficial effects of the method for improving the warping angle of additive manufacturing according to the present application are further described below in conjunction with specific embodiments.

[0062] Laser repair of Ti17 alloy thin-walled parts

[0063] In actual use, the top of a Ti17 alloy thin-walled part was damaged (area 1 to be processed), and the part needed to be repaired. Figure 8 A schematic diagram of the repair process is shown in FIG.

[0064] First, the damaged area 3 is removed by mechanical processing. Figure 8 As shown in the right picture in the figure. Then laser repair is carried out. The repair process will be carried out on the surface to be repaired. The specific steps are as follows.

[0065] (1) Damage machining

[0066] The damaged area 3 at the top of the entire alloy thin-walled part is processed and removed, such as Figure 8 As shown in the left picture.

[0067] (2) 3D modeling of machining area

[0068] According to the original three-dimensional model of the thin-walled part, three-dimensional modeling is performed on the area where the top is removed by mechanical processing through software such as but not limited to UG, CAD, etc.

[0069] (3) Scanning path planning

[0070] The top model area is analyzed. Because the leading and trailing edges of the blade have very small angles, the leading and trailing edges will inevitably warp severely according to the conventional scanning path. Figure 7 The solution shown in Case 2 uses S 2 Strategy: the R-side scanning path only covers the upper corner circle area, not the lower corner circle area; the L-side scanning path only covers the lower corner circle area, not the upper corner circle area; the even-numbered layers can use S 3 Strategy, and S 2 Conversely, on the R side the scan path covers the lower corner circle, while on the L side the scan path covers the upper corner circle area.

[0071] (4) Damage area formation

[0072] According to the scanning path obtained by model processing planning, the damaged area 3 is formed by laser direct deposition technology. The specific parameters can be, for example: laser power 300-500W, scanning rate 400-500mm / min, powder feeding rate 10-12g / min, spot diameter 1mm, and the forming effect is shown in FIG. Fig. 9 .

[0073] from Fig. 9 It can be seen that the left side is a diagram of the repaired surface 2 formed without using the scanning path planning, while the right side is a diagram of the repaired surface formed by using the scanning path planning as described above ( Fig. 9 The area to be repaired after machining in 4).

[0074] From the comparison between the left and right pictures, it can be seen that after adopting the scanning path planning of the present application, the warping problem of the repaired molding surface is greatly improved compared with that without scanning path planning.

[0075] Fig.10 Detailed flowchart of method 10 for improving additive warping based on scanning path planning according to the first preferred embodiment of the present application is shown in FIG.

[0076] like Fig.10 As shown in , the method includes the following steps.

[0077] First, in step 101, the thickness h of the non-corner region of the additive material is determined. 0 .

[0078] Next, at step 102, the thickness h of the corner region of the additive material is determined. 1 .

[0079] Next, in step 103 , different scanning strategies are planned based on the thicknesses h0 and h1 , wherein the deposition times in the corner regions are less than the deposition times in the non-corner regions.

[0080] Finally, at step 104 , the deposition process is performed based on different scanning strategies.

[0081] The scanning path planning process is described in detail below in conjunction with specific embodiments.

[0082] Specifically, if (h 1 -h 0 ) / h 0 =1, that is, when the thickness of the corner area is equal to twice that of the non-corner area, the following scanning strategy is executed for the subsequent layers: Strategy S 1 , then execute strategy S 0 .like Figure 2 As shown in . Among them, strategy S 0 To deposit the complete path, strategy S 1 This is the path for depositing areas other than corners.

[0083] If (h 1 -h 0 ) / h 0 >1, that is, when the thickness of the corner area is greater than twice that of the non-corner area, the following scanning strategy is performed for the subsequent layers: alternately use S 0 and S 1 strategy, until an even number of layers 2n, n*(h 1 -2h 0 )=h 0 If n*(h 1 -2h 0 ) / 2=h 0 , then the next 2n+1 layers use S 0 Strategy, 2n+2 layers use S 1 Strategy, 2n+3 layers use S 1 strategy, and then recalculate the number of layers from scratch, such as Figure 3 as shown in .

[0084] If (h 1 -h 0 ) / h 0 ≤0.5, then calculate h 0 / (h 1 -h 0 ) and take the integer m of the ratio, and then use the first m layers S 0 Scanning strategy, the next layer uses S 1 Scanning strategies, such as Figure 4 as shown in .

[0085] If 0.5<(h 1 -h 0 ) / h 0 <1, then calculate the integer p such that (p+1)*h 1 =(2p+1)*h 0 , and adopt S 0 and S 1 The scanning strategy is carried out alternately until the pth alternating cycle, and S is used in the 2p+1 layer. 0 Scanning strategies, such as Figure 5 as shown in .

[0086] According to another preferred embodiment, step 103 may also be implemented by executing different scanning strategies for different sections in the same deposition layer.

[0087] Specifically, a segmented scanning method is used for each layer, and different layers are alternately scanned. Figure 6 The strategy of S and S' shown in .

[0088] The S strategy covers the corners on the L side, as shown in the dotted circle in the left figure, while the R side scan path does not cover the circle area. The S' strategy is the opposite of S, that is, the R side scan path covers the corners, while the L side scan path does not cover them.

[0089] According to another preferred embodiment, step 103 can also be implemented by the following steps.

[0090] The same deposition layer is scanned in sections, and different layers are scanned alternately. Figure 7 The S shown in 2 With S 3 strategy. Among them, S 2 The strategy covers only the lower corner circle area on the L side, but not the upper corner circle area, and only the upper corner circle area on the R side, but not the lower corner circle area. 3 The strategy is to scan the path on the R side to cover the lower corner circle, and on the L side to cover the upper corner.

[0091] In combination with the above embodiments, those skilled in the art can solve the warping problem generated in the manufacture of additive parts by adopting different scanning strategies for different deposition layers and / or adopting different scanning strategies for different sections of the same deposition layer. In addition, the solution of the present application does not require the addition of machine tools with other special functions such as arc transitions, thereby reducing hardware costs, and does not require the use of any other special scanning software, thereby reducing software costs. The solution of the present application utilizes the forming characteristics of different scanning paths, sets different scanning strategies in different deposition layers, and realizes the characteristic of eliminating the warping of the formed parts. In addition, the solution of the present application is highly feasible and is applicable to any programmable laser direct deposition equipment. The solution of the present application also does not require idle operation, has high deposition efficiency, and has good forming effect.

[0092] According to various aspects, elements, or any part of elements, or any combination of elements of the present disclosure, a "processing system" including one or more processors can be implemented. Examples of processors include: microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform various functionalities described throughout the present disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether it is described in software, firmware, middleware, microcode, hardware description language, or other terms. Software may reside on a computer-readable medium. The computer-readable medium may be a non-transient computer-readable medium. As examples, non-transitory computer-readable media include: magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs)), smart cards, flash memory devices (e.g., memory cards, memory sticks, key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. As examples, computer-readable media may also include carrier waves, transmission lines, and any other suitable medium for transmitting software and / or instructions that can be accessed and read by a computer. The computer-readable medium may reside in the processing system, be external to the processing system, or be distributed across multiple entities including the processing system. The computer-readable medium may be implemented in a computer program product. As examples, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how to best implement the described functionality presented throughout this disclosure depending on the specific application and the overall design constraints imposed on the overall system.

[0093] It should be understood that the specific order or hierarchy of steps in the disclosed methods is an illustration of an exemplary process. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the methods or methodologies described herein may be rearranged. The attached method claims present elements of the various steps in a sample order and are not meant to be limited to the specific order or hierarchy presented unless specifically stated herein.

[0094] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the universal principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but should be granted the full scope consistent with the language of the claims, wherein the singular reference to the element is not intended to mean "there is and only one" (unless specifically stated) but "one or more". Unless specifically stated otherwise, the term "some" refers to one or more. The phrase "at least one" quoting a list of items refers to any combination of these items, including a single member. As an example, "at least one of a, b or c" is intended to cover: at least one a; at least one b; at least one c; at least one a and at least one b; at least one a and at least one c; at least one b and at least one c; and at least one a, at least one b and at least one c. The elements of the various aspects described throughout this disclosure are all structurally and functionally equivalent schemes currently or hereafter known to those of ordinary skill in the art, and are expressly incorporated herein by reference, and are intended to be covered by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

1. A method for improving the warping of additive manufacturing based on scanning path planning. It is characterized in that The method comprises the following steps: Determine the thickness h of the non-corner area of ​​the additive 0 ; Determine the thickness h of the corner region of the additive 1 ; Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies; performing a deposition process based on the different scanning strategies, The deposition times of the corner region are less than the deposition times of the non-corner region.

2. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: If (h 1 -h 0 ) / h 0 =1, then execute strategy S for the next layer 1 , execute strategy S for the next layer 0 , where strategy S 0 The scanning path covers the complete path of the corner area and the non-corner area, and the strategy S 1 The scanning path only covers the non-corner area.

3. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: If (h 1 -h 0 ) / h 0 >1, then strategy S is executed alternately for subsequent layers 0 and Strategy S 1 , until an even number of layers 2n satisfies: n*(h 1 -2h 0 )=h 0 , then the next 2n+1 layers execute S 0 Strategy, 2n+2 layer execution S 1 Strategy, 2n+3 layer execution S 1 strategy, and then recalculate the number of layers from scratch.

4. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: If (h 1 -h 0 ) / h 0 ≤0.5, then calculate h 0 / (h 1 -h 0 ) and take the integer m of the ratio, and then perform S on the first m layers 0 strategy, followed by a layer of execution S 1 Strategy.

5. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: If 0.5<(h 1 -h 0 ) / h 0 <1, then calculate the integer p such that (p+1)*h 1 =(2p+1)*h 0 , and alternately execute strategy S for subsequent layers 0 and Strategy S 1 , until after the pth alternating cycle, S is executed on the 2p+1 layer 0 Scanning strategy.

6. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: The strategy of alternately executing S and S' for different sections of each deposition layer and / or for different deposition layers, The S strategy is to cover the corner area on the left scanning path, but not on the right scanning path, and The S' strategy is that the left scanning path does not cover the corner area, while the right scanning path covers the corner area.

7. The method according to claim 1, It is characterized in that Based on the thickness h 0 With the thickness h 1 To plan different scanning strategies include: S is performed alternately for different sections in each deposition layer and / or for different deposition layers. 2 With S 3 strategy, Where S 2 The strategy is that the left scanning path only covers the lower corner of the corner area, but not the upper corner of the corner area, and the right scanning path only covers the upper corner, but not the lower corner, and Where S 3 The strategy is that on the left side the scanning path only covers the upper corner but not the lower corner, and on the right side the scanning path only covers the lower corner but not the upper corner.

8. The method according to any one of claims 1 to 7, It is characterized in that Strategies for executing scan paths that do not cover the corresponding area include: The corresponding areas will not be opened and powder will not be delivered.

9. The method according to any one of claims 1 to 7, It is characterized in that Different scanning strategies are performed for different sections of the same deposition layer and / or for different deposition layers.

10. An additive manufacturing method, It is characterized in that The additive manufacturing method comprises the following steps: removing a damaged area of ​​the additive; Performing three-dimensional modeling on the additive material; Performing scanning path planning using the method according to any one of claims 1 to 9; and Repairing of the damaged area is performed based on the scan path planning.

11. A computer readable medium having instructions stored thereon, which, when executed by a processor, perform the method according to any one of claims 1 to 10.

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