Method for correcting thin-wall cavity type parts

Abstract

The invention discloses a correction method for thin-wall cavity type parts, relates to the technical field of part machining, and aims at solving the problem that the rejection rate of the thin-wall cavity type parts is high. The method comprises the following steps: acquiring first scanning detection data and material attributes of a first part; determining deformation data in the cavity of the first part, and further obtaining a first space structure in the cavity of the part; determining a first filling material for filling the first space structure according to the material attribute of the first part; the first space structure is filled with a first filling material, and a second part is obtained; further performing shape correction on the second part by adopting a preset shape correction scheme to obtain a corrected third part; and the form and position precision of the first part is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of part processing, and in particular to a correction method for a thin-walled cavity type part. BACKGROUND

[0002] In the prior art, a common method for manufacturing a double-layer or multi-layer special-shaped curved thin-walled part is lost foam casting or forging blank machining, and some are manufactured by using a laser selective melting additive process. Due to the weak rigidity of the hollow curved thin-walled part, the part often deforms unstably during the heat treatment process after additive forming, resulting in problems such as out-of-tolerance of shape and position in some areas, which cannot meet the use requirements and need to be corrected to meet the design requirements. For example, in the design of a hollow blade and a bending-twisting plate structure of an aero-engine, the double-layer or multi-layer special-shaped curved thin-walled part is often used. During the production process of this type of part, the part often deforms unstably, resulting in out-of-tolerance of shape and position in some areas, which cannot meet the customer's requirements, and the part needs to be corrected. Because of the structural limitations in the thin-walled curved cavity, it is not possible to place a conformal metal tool to constrain the shape correction, so the contour accuracy of the part cannot be restored, which cannot meet the design requirements, resulting in a high scrap rate of the thin-walled cavity type part. SUMMARY

[0003] The present application relates to the technical field of part processing, and in particular to a correction method for a thin-walled cavity type part.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] The present application provides a correction method for a thin-walled cavity type part, which can include:

[0006] Obtaining first scanning detection data and material properties of a first part; the first part is a thin-walled cavity type part;

[0007] Based on the deformation data in the cavity of the first part, a first spatial structure inside the cavity of the first part is determined; the deformation data in the cavity of the first part is determined by comparing the first scanning detection data with the design data of the first part;

[0008] According to the material properties of the first part, a first filling material for filling the first spatial structure is determined; the first filling material includes ceramic particles;

[0009] The first spatial structure is filled with the first filling material to obtain a second part;

[0010] The second part is subjected to shape correction by using a preset shape correction scheme, so as to obtain a third part, which is a corrected part.

[0011] Compared with the prior art, the correction method for the thin-wall cavity part provided by the application solves the problem of high scrap rate of the thin-wall cavity part caused by the fact that the thin-wall cavity part cannot be placed in a conformal metal tooling for constraint correction shape. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application. In the drawings:

[0013] Figure 1 The main flowchart of the correction method for the thin-wall cavity part provided by the application;

[0014] Figure 2 The schematic diagram of the first filling material of the correction method for the thin-wall cavity part provided by the application;

[0015] Figure 3 The mold structure schematic diagram of the correction method for the thin-wall cavity part provided by the application. DETAILED DESCRIPTION

[0016] In order to clearly describe the technical solutions of the embodiments of the application, in the embodiments of the application, the same items or similar items with basically the same functions and effects are distinguished by using "first", "second", etc. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not limit the order. Those skilled in the art can understand that "first", "second", etc. do not limit the quantity and execution order, and "first", "second", etc. also do not necessarily mean different.

[0017] It should be noted that in the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the exemplary or for example embodiments are presented so as to enable a clear and concise disclosure of the present application.

[0018] In the present application, "at least one" means one or more, and "multiple" means two or more. The relationship between the associated objects described by "and / or" indicates that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b and c can be single or multiple.

[0019] In the prior art, the hollow blade and the bending and twisting plate structure of the aero-engine are designed as double-layer or multi-layer special-shaped curved thin-walled parts. Such parts are traditionally formed by lost foam casting or forged blanks machining, and recently some are manufactured by laser selective melting additive process. Such parts are mostly hollow double-layer curved surface structures. Due to structural limitations, it is impossible to place and fill metal fixtures in the curved cavity to constrain and correct the shape. In addition to the deformation of additive printing and the deformation during the heat treatment after printing, similar parts manufactured by machining of forged blanks will also deform due to machining stress, resulting in instability and deformation of the curved thin wall.

[0020] Based on this, the present application is directed to thin-walled cavity parts, which are filled with filler materials such as ceramic particles in the cavity, and then corrected to ensure that the shape and position tolerances of the thin-walled cavity parts meet the design requirements, thereby reducing the scrap rate of such parts.

[0021] Please refer to Figure 1 , Figure 1 The main flowchart of the correction method for the thin-walled cavity type part provided by the present application is shown in the figure.

[0022] In Figure 1 , the method can include:

[0023] Step 110: obtaining first scanning detection data and material properties of a first part; the first part is a thin-walled cavity type part.

[0024] In this step, the first scanning detection data can include two-dimensional detection data or three-dimensional detection data; there are many ways to obtain the first scanning detection data of the first part, such as obtaining three-dimensional scanning data of the first part by using a three-dimensional scanning method when obtaining three-dimensional scanning data. The material attribute can be provided by the user or identified based on the existing technology to obtain the material attribute of the first part; the aero-engine has more curved surface hollow thin-walled parts, for example, a certain type of bracket, material GH5188. The bracket is a double-layer thin-walled structure, and the upper and lower skin wall thicknesses are both 1.5 mm. The deformation reason of such thin-walled cavity type parts is usually deformation caused by additive printing, heat treatment or machining stress.

[0025] Step 120: determining a first space structure inside the first part cavity based on the deformation data inside the first part cavity; the deformation data inside the first part cavity is determined based on the comparison between the first scanning detection data and the design data of the first part.

[0026] In this step, the first scanning detection data is compared and analyzed with the design data to determine the deformation data inside the cavity of the first part, such as the deformation area and the deformation amount of each deformation area. For example, the aero-engine part is deformed after laser selective melting additive printing forming and heat treatment, and the three-dimensional scanning data after deformation can be obtained by a three-dimensional scanning method. The following data can be obtained: both the two layers of skin are deformed, one side is concave, and the maximum deformation is-1.2 mm; the other side is deformed by 1.5 mm. The design requires that the contour accuracy is ±0.25 mm; the data result shows that the contour accuracy of the part in the cavity does not meet the requirements, and shape correction is needed.

[0027] It should be noted that if the internal space structure of the part is determined to meet the design requirements by the first scanning detection data, it can be determined that the contour and position accuracy of the part is qualified, and the related operations of steps 130 to 150 are not needed; the technical means of the embodiments of the present application mainly aims at the thin-walled cavity type parts whose contour and position accuracy does not meet the design requirements.

[0028] Step 130: determining a first filling material for filling the first space structure according to the material attribute of the first part; the first filling material includes ceramic particles.

[0029] Step 140: filling the first space structure with the first filling material to obtain a second part.

[0030] In steps 130 to 140, because the support plate of the thin-walled cavity part is a spatial curved surface structure, the two layers of skin and the two end portions form a forming cavity, and the remaining two sides are not closed in design. The single-layer curved thin-walled structure can be loaded with a convex-concave mold tool for pressure correction or manually hammered with a half mold, while the thin-walled cavity structure cannot use the above methods. Under the condition of no support inside the cavity, it will collapse under stress. For example, the aero-engine blade and the phase change plate of the satellite are also thin-walled cavity structures, and there is also the problem of printing deformation and heat treatment deformation. Because of the internal cavity, the traditional tooling or manual hammering correction method is not applicable.

[0031] Therefore, according to the material properties of the part, the filling material for the first spatial structure is determined in the embodiment of the application. For example, if high-temperature alloy or titanium alloy is used for the engine blade of aviation power, the filling material can be ceramic particles, but not water or other liquids.

[0032] Further, the first spatial structure is filled with the determined filling material, and a second part, i.e., the thin-walled cavity part filled with the filling material, is obtained. At this time, the shaped part (second part) has been prepared and can be subjected to shape correction according to a predetermined shape correction scheme.

[0033] Step 150: The second part is subjected to shape correction according to a predetermined shape correction scheme to obtain a third part, which is a corrected part.

[0034] In this step, the shape correction scheme determined according to the shape error of the first part is used for shape correction, including applying different loads, temperatures, and holding times to perform related operations on the correction tooling to obtain the corrected part, thereby avoiding the technical problems that the thin-walled cavity structure part cannot be subjected to correction by a conventional half-mold correction scheme and cannot be placed in a shaped metal tooling for constraint correction shape.

[0035] Preferably, in step 120, the deformation data can include a deformation area and a deformation amount.

[0036] The determination of the first spatial structure inside the cavity of the first part can include determining the first spatial structure inside the cavity of the first part based on the deformation area and the deformation amount.

[0037] Specifically, the deformation data may also include the correspondence between each deformation area, such as relative distance, relative height, etc.; using these deformation data, the spatial structure inside the cavity of the first component can be constructed; based on the constructed spatial structure, the quantity and specifications of the required filling material can be pre-determined, thereby further improving the efficiency of adding the filling material.

[0038] Furthermore, in step 120, how to determine the first filling material for filling the first space structure may also be determined in combination with the following requirements:

[0039] 1. The filling material is required to be impact-resistant, high in hardness, and have a certain toughness to avoid breakage when load is applied.

[0040] 2. The filling material is required to be resistant to high temperature oxidation when used for thermal correction.

[0041] 3. The expansion coefficient of the filling material is required to be close to that of the metal material to avoid the generation of gaps inside the cavity after heating due to the difference in expansion coefficient, which will not achieve the uniform force correction effect.

[0042] 4. The filling material needs to be resistant to high temperature adhesion to prevent the pellets from sticking together after heating and pressurizing, and from being unable to be removed from the cavity.

[0043] Preferably, in the embodiment of the present application, yttria-stabilized zirconia ceramic particles (Y-TZP, 95 zirconia, Y2O3 content 5.2%) can be used as the first filling material. The ceramic particles are a high-temperature structural material with excellent thermal stability, corrosion resistance, and wear resistance; see Figure 2 , Figure 2 A schematic diagram of the first filler material used in a method for correcting thin-walled cavity components provided by the present invention. The yttria-stabilized zirconia ceramic particles meet the technical requirements for filler materials in the embodiments of this application and can be used to correct the skin of thin-walled cavity components, such as hollow, thin-walled parts with numerous curved surfaces in aircraft engines.

[0044] Furthermore, in step 140, filling the first spatial structure with the first filling material may include: filling the first spatial structure with the first filling material of different specifications based on a first ratio, so that the first spatial structure is completely filled with the first filling material. The first ratio may be a first ratio determined based on the first spatial structure, or a ratio obtained based on historical data statistics.

[0045] Specifically, the filling ratio described in the embodiment of the present application represents a first ratio set for the specification of the determined first filling material. Figure 2As shown in the middle, three specifications of the first filling material can be used, and the particles with a diameter of 3 mm are large particles, the particles with a diameter of 1 mm are medium particles, and the particles with a diameter of 0.5 mm are small particles. Of course, more specifications of the first filling material can also be selected to fill the first space structure; for example, if three specifications of the first filling material are selected, the first ratio can be 1:1:1; if four specifications of the first filling material are selected, the first ratio can be 1:1:1:1; and the like.

[0046] It should be noted that the first filling ratio is not specifically limited in the present scheme, as long as the first space structure can be filled by using the first ratio, and the preset shape correction scheme is met.

[0047] Preferably, in the embodiment of the present scheme, the cavity is filled with ceramic particles and packaged. The ceramic particle beads can be mixed and installed with different diameter specifications such as 1 mm, 2 mm, and 3 mm, and the ratio can be selected as 1:1:1. The main purpose is to fill the cavity completely, and the entire first space structure is filled with the ceramic particles.

[0048] Further, before the second part is corrected in shape according to the preset shape correction scheme, a design of a shape correction tool for correcting the first part can be determined based on the shape correction scheme.

[0049] And the shape correction scheme is determined according to the material properties and deformation data of the first part; the shape correction scheme includes any one of tool convex-concave die room temperature pressurization correction, semi-die manual correction, and tool convex-concave die pressurization heat correction.

[0050] According to the material properties and deformation data of the first part, it is determined whether room temperature concave-convex die loading is needed; if room temperature concave-convex die loading is needed, a loading scheme is determined based on the material properties of the first part and the wall thickness of the shape correction tool; the loading scheme includes at least one of the load value, the temperature range, the pressure maintaining time, and the heat preservation time that need to be loaded.

[0051] As an example, a shape correction tool is designed according to the shape correction scheme, and the tool is generally a convex-concave die structure. As shown in Figure 3 , Figure 3 is a mold structure schematic diagram of a correction method for a thin-walled cavity part provided by the present application. As shown in the shape correction tool, Figure 3 When room temperature correction is performed, the material of the shape correction tool can be selected as 45 steel; when heat correction is performed, the material of the shape correction tool can be selected as 304 or 310S stainless steel.

[0052] Further, after the shape correction tool is determined, the second part filled with the first filling material according to the preset proportion can be placed inside the shape correction tool to apply a load to the shape correction tool to correct the shape of the second part.

[0053] Further, based on the determined shape correction scheme, when room temperature punch-die loading is required, the tool is clamped on the press and then loaded. The specific pressure can be set according to the material strength and area of the first part. When hot correction is required, heating and pressurization are required for correction, and a hot forming device is selected for correction.

[0054] Preferably, the material properties can include high-temperature alloys or titanium alloys, and the loading scheme can include: if the material properties of the first part are high-temperature alloys, the temperature range applied to the shape correction tool is 800-900°C; if the material properties of the first part are titanium alloys, the temperature range applied to the shape correction tool is 700-800°C. The holding time and pressure holding time can also be determined according to the material of the first part and the wall thickness of the shape correction tool, for example, the holding time can be selected to be 5-120 minutes, and the pressure holding time can be selected to be 10-20 minutes.

[0055] Further, in order to improve the shape and position accuracy of the cavity type part, in step 150, the shape correction of the second part using the preset shape correction scheme can include: using the preset shape correction scheme to correct the shape of the second part multiple times, scanning and detecting the correction result of any time to obtain second scanning detection data; determining a second space structure inside the cavity of the first part according to the second scanning detection data; determining whether the shape and position tolerance of the third part is greater than a preset threshold value according to the second scanning detection data and the second space structure; if the shape and position tolerance of the third part is less than or equal to the preset threshold value, the part corresponding to the second space structure is determined as the third part; if the shape and position tolerance of the third part is greater than the preset threshold value, the proportion of fine particle filling material in the first filling material inside the cavity of the third part is increased to obtain a second proportion; and based on the second proportion, the part corresponding to the second space structure is corrected in shape.

[0056] According to the second scanning detection data and the second space structure, it is determined whether the shape and position tolerance of the third part is greater than a preset threshold value. The preset threshold value can be a precision threshold value set to meet higher factory requirements, for example, if the contour accuracy is less than or equal to 0.2mm, the product is a qualified product. If the contour accuracy cannot be improved to 0.2mm, the product is an unqualified product and needs to be scrapped.

[0057] In the embodiment for improving the shape and position accuracy of the cavity type component, compared with the foregoing shape correction method, the difference is that the proportion of the fine particle filling material in the first filling material is increased, for example, the proportions of the large, medium and small regular first filling materials are 1:1:1.5, and the second proportion is used to correct the shape of the second space structure. As to how to determine the second space and correct the component corresponding to the second space structure, including filling the first filling material, applying load to the shape correction tool, and other technical means are the same as those of the foregoing shape correction method, and will not be described here.

[0058] It should be noted that the following control measures can be used in the shape correction process:

[0059] 1) In order to avoid cracking of the component during the shape correction process, it is necessary to ensure that the surface is free of microcracks before shape correction. Avoid "wound" shape correction, and crack caused by load stress. The component should be subjected to nondestructive testing (ray and fluorescence) before shape correction.

[0060] 2) When the component is hot-shaped, an intermediate preheating process can be set, and the furnace cooling process is performed after the pressure holding is completed.

[0061] 3) In order to prevent the cavity from being deformed by pressure to form a pit, the zirconia ceramic particles filled must be of various diameters, and mixed and filled.

[0062] Based on this, the shape correction method for the thin-walled cavity type component in the embodiment of the application uses zirconia ceramic particles to fill the thin-walled inner cavity, fully utilizes the hardness and toughness of the zirconia ceramic particles to transfer the load force in the shape correction process, designs a shape following tool to ensure the accuracy of the curved surface, realizes the shape correction of the deformed thin-walled cavity, restores the shape and position accuracy of the component, and avoids the problem of high scrap rate of the thin-walled cavity type component.

[0063] The shape correction method for the thin-walled cavity type component provided in the application obtains first scanning detection data and material properties of a first component; determines a first space structure inside a cavity of the first component based on deformation data inside the cavity of the first component; determines a first filling material for filling the first space structure according to the material properties of the first component; fills the first space structure with the first filling material to obtain a second component; corrects the shape of the second component by using a preset shape correction scheme to obtain a third component, which is a corrected component; thereby improving the shape and position accuracy of the deformed component, and solving the problem of high scrap rate of the thin-walled cavity type component due to the fact that the shape cannot be corrected by placing a shape following metal tool inside the thin-walled cavity type component.

[0064] Although the application has been described in connection with various embodiments thereof, it will be understood that the application is capable of further modifications and that this application is intended to cover any and all such variations, using the scope of the claims. In the claims, the term comprising does not exclude the presence of other elements or steps than those listed in a claim. The term "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. A single processor or other unit can fulfil the functions of several items recited in the claims. The terms "first", "second" and the like in the description do not necessarily imply that there are two or more items. Embodiments of the application can relate to any of the specific features and combinations thereof without necessarily referring to the corresponding drawings.

[0065] Although the application has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any and all such variations, using the scope of the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. It is intended that the application cover all alternatives, modifications and equivalents falling within the scope of the claims. It will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the application. It is intended to cover in the appended claims all such changes and modifications that fall within the scope of the application.

Claims

1. A correction method for thin-walled cavity parts, characterized in that: include: Acquire first scanning detection data and material properties of a first component; the first component is a thin-walled cavity component; determining a first spatial structure inside the first component cavity based on deformation data within the first component cavity; the deformation data within the first component cavity is deformation data determined based on comparison of the first scanning detection data with design data of the first component; determining a first filling material for filling the first spatial structure according to the material properties of the first component; the first filling material includes ceramic particles; Filling the first spatial structure with the first filling material to obtain a second component; The second component is shape-corrected using a preset shape correction scheme to obtain a third component, where the third component is a corrected component.

2. The method according to claim 1, wherein The deformation data includes a deformation area and a deformation amount; Determining the first spatial structure inside the cavity of the first component includes: Based on the deformation area and the deformation amount, a first spatial structure inside the cavity of the first component is determined.

3. The method according to claim 1, wherein Filling the first space structure with the first filling material includes: Based on the first ratio, the first space structure is filled with the first filling materials of different specifications, so that the first space structure is fully filled with the first filling materials.

4. The method according to claim 1, wherein The step of correcting the shape of the second component by using a preset shape correction scheme further includes: Based on the material properties and deformation data of the first component, the shape correction scheme is determined; the shape correction scheme includes any one of room temperature pressurization correction of the tooling convex and concave dies, manual correction of the half mold, and pressurization and hot correction of the tooling convex and concave dies.

5. The method according to claim 4, wherein Also includes: Determining whether room temperature concave and convex die loading is required based on the material properties and deformation data of the first component; If room temperature concave and convex die loading is required, a loading scheme is determined based on the material properties of the first component and the wall thickness of the shaping tooling; The loading scheme includes at least one of a load value to be loaded, a temperature range, a pressure holding time, and a heat holding time.

6. The method according to claim 5, wherein The loading scheme also includes: During the heat correction of parts, an intermediate preheating treatment is set, and after the pressure holding is completed, a furnace cooling treatment is set.

7. The method according to claim 5, wherein The material properties include: high temperature alloy or titanium alloy; The loading scheme includes: If the material property of the first component is a high-temperature alloy, the temperature range applied to the correction tool is 800°C to 900°C; if the material property of the first component is a titanium alloy, the temperature range applied to the correction tool is 700°C to 800°C.

8. The method according to claim 4, wherein Also includes: Based on the shape correction scheme, a shape correction tool design for performing shape correction on the first component is determined.

9. The method according to claim 1, wherein The step of correcting the shape of the second component by using a preset shape correction scheme includes: Performing multiple shape corrections on the second component using the preset shape correction scheme, and scanning and detecting any correction result to obtain second scanning detection data; determining a second spatial structure inside the first component cavity based on the second scanning detection data; determining, based on the second scanning detection data and the second spatial structure, whether a form and position tolerance of the third component is greater than a preset threshold; If the geometric tolerance of the third component is less than or equal to a preset threshold, the component corresponding to the second spatial structure is determined as the third component; If the shape and position tolerance of the third component is greater than a preset threshold, increasing the proportion of fine particle filling material in the first filling material inside the cavity of the third component to obtain a second proportion; Based on the second ratio, shape correction is performed on components corresponding to the second spatial structure.

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