Laser engineered net shaping method for regulating gas film hole size

Abstract

The present application relates to the technical fields of laser selective melting forming, and particularly relates to a laser selective melting forming method for regulating and controlling gas film hole size, comprising the following steps: (a) adjusting profile process parameters of a printed gas film hole feature structure part, and analyzing and determining target profile process parameters; (b) adjusting lower surface process parameters of the printed gas film hole feature structure part, and analyzing and determining target lower surface process parameters; (c) adjusting spot size parameters, and analyzing and determining target spot size parameters; (d) under the condition that the aforementioned parameters are unchanged, adjusting part placement angle, and analyzing and determining target part placement angle. Through the combined optimization of the profile process parameters, the lower surface process parameters, the spot size and the placement angle, the hole wall roughness, the roundness and the aperture size of the gas film hole on the blade surface are considered, so that the control of the gas film hole size in the laser selective melting forming process is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser selective melting forming, in particular to a laser selective melting forming method for regulating and controlling the size of a gas film hole. BACKGROUND

[0002] During the long-time work of an aero-engine at a high temperature, the blade must be cooled, and the cooling of the blade can be achieved through a gas film hole. The gas film hole mainly provides a cooling gas flow to cover the profile of the blade, thereby reducing the working temperature thereof. In order to obtain a good cooling efficiency, a plurality of gas film holes with different inclination angles and arrangement modes need to be machined on the surface of the blade, and the hole diameter of the gas film hole is generally about 0.3-0.6 mm. The machining precision and quality of the gas film hole determine the reliability of the turbine blade, and further affect the safety of the aero-engine.

[0003] When the laser selective melting forming process is used to prepare a gas film hole, the inclination angle and arrangement mode of the gas film hole on the surface of the blade are different. Therefore, how to regulate and control the forming process to ensure the hole diameter, roundness and hole wall roughness of the gas film hole on the surface of the blade after laser selective melting forming is a pain point that the laser selective melting forming for preparing a gas film hole has been facing.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The present application aims to provide a laser selective melting forming method for regulating and controlling the size of a gas film hole, which can ensure the hole wall roughness, roundness and hole diameter size of the gas film hole on the surface of the blade, thereby realizing the control of the size of the gas film hole in the laser selective melting forming process.

[0006] In order to achieve the above-mentioned purpose of the present application, the present application provides a laser selective melting forming method for regulating and controlling the size of a gas film hole, which comprises the following steps:

[0007] (a) adjusting the profile process parameters used for printing a gas film hole feature structure, determining target profile process parameters according to the surface roughness of the printed gas film hole feature structure;

[0008] (b) adjusting the lower surface process parameters of the printed gas film hole feature structure under the condition that the target profile process parameters are unchanged, determining target lower surface process parameters according to the slag hanging condition and the forming state of the lower surface of the printed gas film hole feature structure;

[0009] (c) adjusting the spot size parameters under the condition that the target profile process parameters and the target lower surface process parameters are unchanged, determining target spot size parameters according to the size and micro-morphology of the printed gas film hole feature structure;

[0010] (d) adjusting the part placement angle, and determining the target part placement angle according to the roughness, size and micro-morphology of the air film hole feature part obtained by printing, under the condition that the target profile process parameters, the target bottom surface process parameters and the target spot size parameters remain unchanged.

[0011] In the specific embodiments of the present application, the profile process parameters include laser power, scanning speed and profile offset.

[0012] In the specific embodiments of the present application, in step (a), at least 12 different combinations of profile process parameters are used when adjusting the profile process parameters. Further, when adjusting the profile process parameters, the laser power is adjusted in the range of 130-190 W; the scanning speed is adjusted in the range of 340-420 mm / s; and the profile offset is adjusted in the range of -0.03-0.03 mm.

[0013] In the specific embodiments of the present application, the method for determining the target profile process parameters includes: preliminarily screening the obtained air film hole feature parts by using a roughness comparison block, and selecting 3-5 groups of air film hole feature parts with the smallest roughness; performing quantitative analysis of the roughness of the selected 3-5 groups of air film hole feature parts by using a roughness measuring instrument, and performing porosity comparison analysis by using an optical microscope, and selecting 1 group of air film hole feature part with the smallest roughness, and the corresponding profile process parameters are the target profile process parameters.

[0014] In the specific embodiments of the present application, the bottom surface process parameters include laser power, scanning speed and profile offset.

[0015] In the specific embodiments of the present application, in step (b), at least 12 different combinations of bottom surface process parameters are used when adjusting the bottom surface process parameters. Further, when adjusting the bottom surface process parameters, the laser power is adjusted in the range of 40-100 W; the scanning speed is adjusted in the range of 1400-2000 mm / s; and the profile offset is adjusted in the range of -0.02-0.02 mm.

[0016] In the specific embodiments of the present application, the method for determining the target bottom surface process parameters includes: preliminarily screening by visual comparison, and selecting 3-5 groups of air film hole feature parts with the lightest bottom surface slag; performing micro-contrast analysis of the bottom surface morphology of the selected 3-5 groups of air film hole feature parts by using an optical microscope, and selecting 1 group of air film hole feature part with the best bottom surface roundness, and the corresponding bottom surface process parameters are the target bottom surface process parameters.

[0017] In the specific embodiment of the present application, in step (c), at least 7 different combinations of spot size parameters are used to adjust the spot size parameters.

[0018] In the specific embodiment of the present application, the method for determining the target spot size parameter comprises: screening the obtained gas film hole feature structure by using a plug gauge to select 3-4 groups of gas film hole feature structures closest to the preset requirements; and performing comparative analysis on the micro-morphology of the selected 3-4 groups of gas film hole feature structures by using an optical microscope to select 1 group of gas film hole feature structure with the smallest roughness and the best shaping roundness of the lower surface, and the corresponding spot size parameter is the target spot size parameter.

[0019] In the specific embodiment of the present application, in step (d), the adjustment range of the part placement angle is 0°-60°.

[0020] In the specific embodiment of the present application, the method for determining the target part placement angle comprises: performing comparative analysis on the gas film hole feature structure by using a roughness measuring instrument, a plug gauge and an optical microscope to select 1 group of gas film hole feature structure with the smallest roughness and the best shaping roundness of the gas film hole, and the corresponding part placement angle is the target part placement angle.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The present application combines and optimizes the profile process parameters, the lower surface process parameters, the spot size and the placement angle, and takes into account the hole wall roughness, the roundness and the hole size of the gas film hole on the blade surface, so as to realize the control of the gas film hole size in the laser selective melting forming process. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The micro-morphology diagram of the gas film hole feature structure printed by the method provided in Example 1 of the present application;

[0025] Figure 2 The micro-morphology diagram of the gas film hole feature structure printed by the method provided in Comparative Example 1. EMBODIMENT

[0026] The technical solutions of the present application will be clearly and completely described below in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0027] In the existing laser selective melting forming preparation of the gas hole film, only by adjusting the lower surface process parameters, the lower surface forming roundness is adjusted to ensure the roundness of the gas film hole, but the effect is very small. On the one hand, the lower surface process parameters also relate to the fluorescence state of the blade, and the parameter optimization needs to be carried out in the parameter range that ensures the good fluorescence state of the blade, so the adjustment range is narrow. On the other hand, the start of the lower surface process parameters is also related to the placement angle of the part and the opening threshold, and after the placement angle is determined by comprehensively considering the part structure, the angles between the diameters of different gas film holes and the printing plane are inconsistent due to different angles and arrangement modes, and under the same opening condition, the areas of different gas film holes on the lower surface are different, so the optimization effect is very small.

[0028] The present application is aimed at the size control of the small size and different angle gas film holes on the surface of the part, and the specifications of the conventional parts are different. It is found that the small hole size of the gas film hole is mainly affected by the surface roughness and the forming roundness. And due to the particularity of the gas film hole structure (small size and different angles), only the roughness optimization is not enough to meet the size requirements of the gas film hole. It is found through research that, on the basis of roughness optimization, further combining spot compensation and adjusting the energy distribution of the molten pool can assist in achieving good roundness, and finally ensure that the size of the gas film hole with different angles meets the requirements.

[0029] The present application provides a laser selective melting forming method for controlling the size of a gas film hole, comprising the following steps:

[0030] (a) adjusting the profile process parameters used for printing the gas film hole feature structure part, and determining the target profile process parameters according to the surface roughness of the printed gas film hole feature structure part;

[0031] (b) adjusting the lower surface process parameters of the printed gas film hole feature structure part without changing the target profile process parameters, and determining the target lower surface process parameters according to the slag hanging condition and the lower surface forming state of the printed gas film hole feature structure part;

[0032] (c) adjusting the spot size parameter while keeping the target profile process parameter and the target undersurface process parameter unchanged, and determining the target spot size parameter according to the size and microstructure of the gas film hole feature structure obtained by printing;

[0033] (d) adjusting the part placement angle while keeping the target profile process parameter, the target undersurface process parameter and the target spot size parameter unchanged, and determining the target part placement angle according to the roughness, size and microstructure of the gas film hole feature structure obtained by printing.

[0034] The present application ensures the roughness, roundness and size of the hole wall of the gas film hole on the blade surface by further adjusting the profile process parameter, the spot size and the placement angle on the basis of the undersurface process parameter, so as to realize the control of the size of the gas film hole in the laser selective melting forming process.

[0035] In the present application, the spot size is adjusted by changing the irradiance of each region of the molten pool, so that the undersurface molten pool energy is close to the flat-top light beam, the molten pool depth is uniform, the roundness of the undersurface is improved, and the roundness of the gas film hole is ensured.

[0036] In the specific embodiment of the present application, the profile process parameter includes laser power, scanning rate and profile offset.

[0037] By changing the scanning power, scanning rate and profile offset in the profile process parameter, the profile roughness is reduced under the condition of ensuring good powder laying field, so as to ensure the roughness of the hole wall of the gas film hole.

[0038] In the specific embodiment of the present application, in step (a), at least 12 groups of different combinations of profile process parameters are used when adjusting the profile process parameter. Further, when adjusting the profile process parameter, the control range of the laser power is 130-190 W; the control range of the scanning rate is 340-420 mm / s; and the control range of the profile offset is-0.03-0.03 mm.

[0039] In actual operation, in the process of regulating the profile process parameters, when regulating each parameter, after selecting a starting value in the corresponding parameter range, the regulation can be carried out according to an appropriate regulation amplitude. The specific regulation amplitude can be determined according to the degree of influence of the corresponding parameter on the final result. When the influence on the result is large, the regulation amplitude can be appropriately reduced; when the influence on the result is small, the regulation amplitude can be appropriately increased. For example, the regulation amplitude of the laser power can include but is not limited to 15W, 20W, 25W or a range formed by any two of them, the regulation amplitude of the scanning speed can include but is not limited to 15mm / s, 20mm / s, 25mm / s or a range formed by any two of them, and the regulation range of the profile offset can include but is not limited to 0.025mm, 0.03mm, 0.035mm or a range formed by any two of them.

[0040] Among the 12 different combinations of profile process parameters, the laser power, the scanning speed and the profile offset are included. By using different combinations of laser power, scanning speed and profile offset in the corresponding range, the profile process parameters are optimized to reduce the profile roughness while ensuring good powder spreading conditions, so as to ensure the roughness of the hole wall of the gas film hole. The different combination modes of the present application can be selected by conventional permutation and combination, and then the laser power, the scanning speed and the profile offset and other parameters are selected in the regulation range according to an appropriate regulation amplitude.

[0041] For example, in different embodiments, the laser power can be 130W, 140W, 150W, 160W, 170W, 180W, 190W or a range formed by any two of them; the scanning speed can be 340mm / s, 350mm / s, 360mm / s, 370mm / s, 380mm / s, 390mm / s, 400mm / s, 410mm / s, 420mm / s or a range formed by any two of them; and the profile offset can be -0.03mm, -0.02mm, -0.01mm, 0mm, 0.01mm, 0.02mm, 0.03mm or a range formed by any two of them.

[0042] In step (a), when adjusting the profile process parameters used for printing the gas film hole feature, the remaining surface process parameters, the spot size parameters and the part placement angle can correspond to the original default parameters.

[0043] In the specific embodiment of the present application, the method for determining the target profile process parameter comprises: preliminarily screening the obtained gas film hole feature structure by a roughness comparison block, and selecting 3-5 groups of gas film hole feature structures with the smallest roughness; performing quantitative analysis on the roughness of the selected 3-5 groups of gas film hole feature structures by a roughness measuring instrument, and performing porosity comparison analysis by an optical microscope, and selecting 1 group of gas film hole feature structure with the smallest roughness, and the corresponding profile process parameter is the target profile process parameter.

[0044] The method for selecting 3-5 groups of gas film hole feature structures with the smallest roughness comprises: comparing the roughness of all the structures by the roughness comparison block, sequentially sorting according to the size of the roughness, and selecting 3-5 groups with the smallest roughness.

[0045] In the specific embodiment of the present application, the preferred target profile process parameter according to the roughness of the gas film hole feature structure comprises: the laser power range is 150-190 W; the scanning rate range is 380-420 mm / s; and the profile offset is 0-0.03 mm.

[0046] In the specific embodiment of the present application, the lower surface process parameter comprises laser power, scanning rate and profile offset.

[0047] In the specific embodiment of the present application, in step (b), at least 12 different combinations of lower surface process parameters are used when adjusting the lower surface process parameters. Further, when adjusting the lower surface process parameters, the laser power is adjusted in the range of 40-100 W; the scanning rate is adjusted in the range of 1400-2000 mm / s; and the profile offset is adjusted in the range of -0.02-0.02 mm.

[0048] The 12 different combinations of lower surface process parameters each include laser power, scanning rate and profile offset, and the lower surface process parameters are optimized by using different combinations of laser power, scanning rate and profile offset in the corresponding range, so as to maximize the optimization of the gas film hole wall roughness in cooperation with the profile process parameter.

[0049] As in different embodiments, the laser power can be 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, or a range formed by any two of them; the scanning rate can be 1400 mm / s, 1500 mm / s, 1600 mm / s, 1700 mm / s, 1800 mm / s, 1900 mm / s, 2000 mm / s, or a range formed by any two of them; and the profile offset can be -0.02 mm, -0.01 mm, 0 mm, 0.01 mm, 0.02 mm, or a range formed by any two of them.

[0050] In step (b), when adjusting the lower surface process parameters of the printed gas film hole feature structure, the profile process parameters are selected according to the profile process parameters determined in step (a), and the remaining spot size parameters and the part placement angle correspond to the original default parameters.

[0051] In the specific embodiment of the present application, the method for determining the target lower surface process parameters comprises: preliminary screening through visual comparison to select 3-5 groups of gas film hole feature structures with the lightest slag hanging on the lower surface; and microscopically analyzing the lower surface morphology of the selected 3-5 groups of gas film hole feature structures through an optical microscope to select 1 group of gas film hole feature structure with the best roundness of the lower surface, and the corresponding lower surface process parameters are the target lower surface process parameters.

[0052] In the specific embodiment of the present application, according to the forming state of the gas film hole feature structure, the preferred target lower surface process parameters include: a laser power range of 40-80 W; a scanning speed range of 1600-2000 mm / s; and a profile offset of 0-0.02 mm.

[0053] In the specific embodiment of the present application, in step (c), at least 7 different combinations of spot size parameters are used when adjusting the spot size parameters. Further, when adjusting the spot size parameters, the adjustment range is 0.08-0.20 mm.

[0054] Through optimization of the spot size parameters, the lower surface molten pool energy is close to a flat-top light beam, thereby improving the roundness of the lower surface and ensuring the roundness of the gas film hole.

[0055] As in different embodiments, when adjusting the spot size parameters, the spot size parameters can be 0.08 mm, 0.10 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.20 mm, or a range formed by any two thereof.

[0056] In step (c), when adjusting the spot size parameters of the printed gas film hole feature structure, the profile process parameters are selected according to the profile process parameters determined in step (a), the lower surface process parameters are selected according to the lower surface process parameters determined in step (b), and the part placement angle corresponds to the original default parameters.

[0057] In the specific embodiment of the present application, the method for determining the target spot size parameters comprises: preliminary screening of the obtained gas film hole feature structures through a plug gauge to select 3-4 groups of gas film hole feature structures with the closest size to the preset requirements; and microscopically analyzing the comparative analysis of the micro-morphology of the selected 3-4 groups of gas film hole feature structures through an optical microscope to select 1 group of gas film hole feature structure with the smallest roughness and the best forming lower surface roundness, and the corresponding spot size parameters are the target spot size parameters.

[0058] In the specific embodiment of the present application, the preferred target spot size parameter is 0.08-0.10 mm.

[0059] In the specific embodiment of the present application, in step (d), the adjustment range of the part placement angle is 0°-60°.

[0060] As in different embodiments, in step (d), the part placement angle can be 0°, 15°, 30°, 45°, 60° or a range formed by any two of them.

[0061] The present application further optimizes the part placement angle on the basis of the profile process parameters, the target lower surface process parameters and the target spot size parameters. By ensuring that the internal blade is directly formed without support, and under a certain lower surface opening threshold, the range of the lower surface opening of the gas film hole is as small as possible to ensure the aperture size of the gas film hole.

[0062] In the specific embodiment of the present application, the method for determining the target part placement angle comprises: comparing and analyzing the gas film hole feature structures by a roughness measuring instrument, a plug gauge and an optical microscope, selecting a group of gas film hole feature structures with the smallest roughness and the best roundness of the gas film hole forming, and the corresponding part placement angle is the target part placement angle.

[0063] In the specific embodiment of the present application, the preferred part placement angle is a 45° overhang angle.

[0064] The present application adopts the determined profile process parameters, lower surface process parameters and spot size parameters, selects 45° as the part placement angle, and performs selective laser melting forming, so as to finally obtain a gas film hole feature structure part with small roughness and high roundness of the gas film hole forming.

[0065] Example 1

[0066] The present embodiment provides a laser selective melting forming method for regulating and controlling the size of a gas film hole, and the fixed printing layer thickness is 40 layers thick, which comprises the following steps:

[0067] (1) At least 12 groups of different combinations of profile process parameters are adopted to print and form corresponding gas film hole feature structure parts; wherein, in the profile process parameters, the selected regulation range of the laser power is 130-190 W, and the regulation amplitude is 20 W; the selected regulation range of the scanning rate is 340-420 mm / s, and the regulation amplitude is 20 mm / s; the selected regulation range of the profile offset is-0.03-0.03 mm, and the regulation amplitude is 0.03 mm.

[0068] (2) The surface roughness of the air film hole feature structure piece obtained by printing forming in step (1) is preliminarily screened by a roughness comparison block, and 3 groups of air film hole feature structure pieces with the smallest roughness are selected; quantitative analysis of the roughness of the selected 3 groups of air film hole feature structure pieces is carried out by a roughness measuring instrument, and porosity comparison analysis is carried out by an optical microscope, and 1 group of air film hole feature structure pieces with the smallest roughness is selected, and the corresponding profile process parameter is the target profile process parameter; according to the comparison analysis, it is concluded that in the profile process parameter, the laser power is 130 W, the scanning speed is 410 mm / s, and the profile offset is 0.03 mm, and the roughness of the corresponding air film hole feature structure is the best, and the process parameter is taken as the target profile process parameter.

[0069] (3) Under the condition that the determined target profile process parameter is unchanged, at least 12 groups of different combinations of the following surface process parameters are used to print and form corresponding air film hole feature structure pieces; wherein, in the following surface process parameters, the selected control range of laser power is 40-100 W, and the control range is 20 W; the selected control range of scanning speed is 1400-2000 mm / s, and the control range is 200 mm / s; the selected control range of profile offset is-0.02-0.02 mm, and the control range is 0.02 mm.

[0070] (4) The slag hanging condition of the lower surface of the air film hole feature structure piece obtained by printing forming in step (3) is preliminarily screened by visual comparison, and 3 groups of air film hole feature structure pieces with the lightest slag hanging on the lower surface are selected; then the microcosmic comparison analysis of the lower surface morphology of the selected 3 groups of air film hole feature structure pieces is carried out by an optical microscope, and 1 group of air film hole feature structure pieces with the highest roundness of the lower surface forming is selected, and the corresponding lower surface process parameter is the target lower surface process parameter; according to the comparison analysis, it is concluded that in the lower surface process parameter, the laser power is 80 W, the scanning speed is 1600 mm / s, and the profile offset is 0.02 mm, and the lower surface forming roundness of the corresponding air film hole feature structure is the best, and the process parameter is taken as the target lower surface process parameter.

[0071] (5) Under the condition that the determined target profile process parameter and the target lower surface process parameter are unchanged, at least 7 groups of different combinations of the spot size parameter are used to print and form corresponding air film hole feature structure pieces; wherein, the selected control range of the spot size parameter is 0.08-0.20 mm, and the control range is 0.02 mm.

[0072] (6) The size of the air film hole feature structure piece obtained by printing forming in step (5) is preliminarily screened by a plug gauge, and three groups of air film hole feature structure pieces with sizes close to the preset requirement (0.8 mm) are selected; then, comparative analysis of the micro-morphology of the three groups of selected air film hole feature structures is performed by an optical microscope, so as to select one group of air film hole feature structure pieces with the smallest roughness and the best air film hole forming roundness, and the corresponding spot size parameter is the target spot size parameter; according to the comparative analysis, it is obtained that the air film hole feature structure has the smallest roughness and the best air film hole forming roundness when the spot size parameter is 0.08 mm, and the process parameter is taken as the target spot size parameter.

[0073] (7) After the target contour process parameter, the target lower surface process parameter and the target spot size parameter are determined, the determined process parameters are adopted, and a plurality of part placement angles (0°-60°) are adopted to print corresponding air film hole feature structure pieces, and comparative analysis is performed by a roughness measuring instrument, a plug gauge and an optical microscope, so as to determine the optimal part placement angle; according to the comparative analysis, it is obtained that the air film hole feature structure piece has small roughness and high air film hole forming roundness when the part placement angle is 45°.

[0074] (8) The contour process parameter, the lower surface process parameter and the spot size parameter are determined, the part placement angle is selected as 45°, and selective laser melting forming is performed, so that the air film hole feature structure piece with small roughness and high air film hole forming roundness is finally obtained, and the appearance is as shown in Figure 1

[0075] As can be seen from the figure, the lower surface forming state of the air film hole feature structure piece formed by the regulation method is good, and the roundness is high.

[0076] Comparative Example 1

[0077] Comparative Example 1 provides a laser selective melting forming method of an air film hole, adopts default laser forming parameters for selective laser melting forming, and prints an air film hole feature structure piece as a control group.

[0078] The default forming parameters are: the contour process parameter, the laser power is 160 W, the scanning speed is 380 mm / s, and the contour offset is 0 mm; the lower surface process parameter, the laser power is 70 W, the scanning speed is 1700 mm / s, and the contour offset is 0 mm; the spot size parameter is 0.15 mm; and the placement angle is 0°.

[0079] The micro-morphology of the air film hole feature structure piece formed by printing is as shown in Figure 2

[0080] As can be seen from the figure, the forming method of the air film hole in Comparative Example 1 has poor forming state of the lower surface of the air film hole feature structure piece, and low roundness.​​

[0081] From the above, the present application combines and optimizes the profile process parameters, the lower surface process parameters, the light spot size and the placing angle, and ensures the hole wall roughness, roundness and aperture size of the blade surface film hole, so as to realize the control of the film hole size in the laser selective melting forming process.

[0082] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling gas film hole size of laser selective melting formed, characterized in that, The method comprises the following steps: (a) adjusting the profile process parameters for printing the gas film hole feature structure, determining the target profile process parameters according to the surface roughness of the printed gas film hole feature structure; (b) adjusting the lower surface process parameters for printing the gas film hole feature structure without changing the target profile process parameters, determining the target lower surface process parameters according to the slag hanging condition and the forming state of the lower surface of the printed gas film hole feature structure; (c) adjusting the spot size parameters without changing the target profile process parameters and the target lower surface process parameters, determining the target spot size parameters according to the size and micro-morphology of the printed gas film hole feature structure; (d) adjusting the part placement angle without changing the target profile process parameters, the target lower surface process parameters and the target spot size parameters, determining the target part placement angle according to the roughness, size and micro-morphology of the printed gas film hole feature structure; In step (c), at least 7 groups of different combinations of spot size parameters are used when adjusting the spot size parameters, and the control range of the spot size parameters is 0.08-0.20 mm; The method for determining the target spot size parameters comprises: preliminarily screening the obtained gas film hole feature structures by using a plug gauge, and selecting 3-4 groups of gas film hole feature structures with the size closest to the preset requirements; Comparative analysis of the micro-morphology of the selected 3-4 groups of gas film hole feature structures is performed by using an optical microscope, the gas film hole feature structure with the smallest roughness and the best roundness of the formed lower surface is selected, and the corresponding spot size parameters are the target spot size parameters.

2. The method for laser engineered net shaping to regulate gas film hole size according to claim 1, wherein, The profile process parameters comprise laser power, scanning speed and profile offset.

3. The method for laser engineered net shaping to regulate gas film hole size of claim 2, wherein, In step (a), at least 12 groups of different combinations of profile process parameters are used when adjusting the profile process parameters; When the profile process parameters are controlled, the control range of the laser power is 130-190 W, the control range of the scanning speed is 340-420 mm / s, and the control range of the profile offset is -0.03-0.03 mm.

4. The method for laser engineered net shaping to regulate gas film hole size of claim 1, wherein, The method for determining the target profile process parameters comprises: preliminarily screening the obtained gas film hole feature structures by using a roughness comparison block, selecting 3-5 groups of gas film hole feature structures with the smallest roughness, performing quantitative analysis of the roughness of the selected 3-5 groups of gas film hole feature structures by using a roughness measuring instrument, and performing comparative analysis of the porosity by using an optical microscope, selecting one group of gas film hole feature structure with the smallest roughness, and the corresponding profile process parameters are the target profile process parameters.

5. The method for laser engineered net shaping to regulate gas film hole size of claim 1, wherein, The lower surface process parameters comprise laser power, scanning speed and profile offset.

6. The method for laser engineered net shaping to regulate gas film hole size of claim 5, wherein, In step (b), at least 12 groups of different combinations of lower surface process parameters are used when adjusting the lower surface process parameters; When the lower surface process parameters are controlled, the control range of the laser power is 40-100 W, the control range of the scanning speed is 1400-2000 mm / s, and the control range of the profile offset is -0.02-0.02 mm.

7. The method for laser engineered net shaping to regulate gas film hole size of claim 1, wherein, The method for determining the target lower surface process parameter comprises: preliminary screening by visual comparison to select 3-5 groups of air film hole feature structure pieces with the lightest slag hanging on the lower surface; and microscopically comparing and analyzing the lower surface morphology of the selected 3-5 groups of air film hole feature structure pieces by an optical microscope to screen 1 group of air film hole feature structure pieces with the best roundness on the lower surface, and the corresponding lower surface process parameter is the target lower surface process parameter.

8. The method for laser engineered net shaping to regulate gas film hole size of claim 1, wherein, In step (d), the adjustment of the part placement angle comprises 0-60°; The method for determining the target part placement angle comprises: comparing and analyzing the air film hole feature structure by a roughness measuring instrument, a plug gauge and an optical microscope to select 1 group of air film hole feature structure with the smallest roughness and the best air film hole forming roundness, and the corresponding part placement angle is the target part placement angle.

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