Laser-induced ablation of SiC f / SiC milling method and device

Abstract

The present invention relates to a SiC based on laser induced ablation f / SiC milling method and device, the method is: determine SiC f After the cutting allowance d of the SiC composite material is removed, laser induced ablation treatment is performed on it (i.e., a laser beam with high laser power density is used to directly scan the surface of the material), so that the material to be removed with a surface thickness of d1 (d-d2=d1, d2 is the minimum radial cutting width of the material without the affected layer to ensure that the ablation product and the heat-affected layer material are completely removed) becomes a powdered laser induced ablation product, and then milling is performed on it; the device includes a generating device (for forming the laser beam), an adjusting device (for adjusting the relative position of the laser beam and the material so that the laser beam scans on the material along a certain path), a fixture (for mounting the material on a machine tool), a tool and a machine tool (for milling the material). The method of the present invention shortens the processing time, and the structure of the device is simple and easy to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of cutting and processing of ceramic matrix composite materials, and relates to a SiC f / SiC milling method and device. Background Art

[0002] Silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC f / SiC) is a tough ceramic material obtained by adding continuous fiber reinforcement phase to the ceramic matrix for exogenous toughening and optimizing with appropriate weak interface phase. It has excellent comprehensive properties such as light weight, high strength, high temperature resistance, oxidation resistance, corrosion resistance, wear resistance, and high damage tolerance. As a high-temperature resistant composite material with broad application prospects, SiC f / SiC composite materials are mainly used in high-temperature structural parts and long-life high-temperature components, such as aircraft engine tail nozzles, nozzle guide vanes, turbine blades, turbine shroud rings and other hot end components, nuclear fusion reactor cladding first wall, flow channel plug-ins and divertors and other components, and as high-temperature stealth materials for cruise missile noses, engine tail nozzles, hypersonic aircraft surfaces, etc.

[0003] For a qualified SiC with complex structure f / SiC composite parts usually need to be milled after preparation and forming, in order to obtain high-precision and high-quality assembly surfaces and improve the appearance by trimming the shape. f The high hardness, high brittleness, inhomogeneity, and anisotropy of SiC composites lead to extremely poor cutting performance, which poses a great challenge to the milling process. f / SiC composite materials are easily damaged during milling. In order to ensure processing quality, processing efficiency is usually sacrificed, resulting in very long processing time. f The high hardness of the / SiC composite material causes severe tool wear and chipping, and the resulting frequent tool changes are not conducive to ensuring machining accuracy and quality.

[0004] In the literature 1 (An analytical approach on stochastic model for cutting force prediction in milling ceramic matrix composites), a TiAlN coated four-edge carbide end mill was used to analyze the C f / SiC composite materials are milled with a cutting depth of only 0.1 to 0.2 mm and a feed rate of only 1.25 to -6.25 μm / z per tooth.

[0005] Reference 2 (SiC f In the study of the surface morphology of the holes made by ultrasonic high-speed milling of SiC ceramic matrix composites, four-edged carbide tools and diamond-coated tools were used to cut the SiC f / SiC is used for spiral milling with a cutting depth of only 0.03mm and a feed rate of only 3.77μm / z per tooth. When a multi-edge PCD tool is used, the feed rate per tooth is much lower than 1μm / z.

[0006] Patent CN 112059552 A discloses a method for C f A milling method for / SiC composite materials uses a two-edge straight groove PCD milling cutter for milling, with an axial cutting depth of only 0.2 mm and a feed rate of only 6 μm / z per tooth.

[0007] It can be seen that in order to ensure the processing quality, the cutting depth and feed per tooth are set very small when using cutting edge tools to implement milling of ceramic matrix composites, which greatly limits the processing efficiency and leads to extremely long processing time. Various challenges have greatly increased the f The processing cost of SiC composite materials also makes the processing time extremely long.

[0008] Therefore, it is urgent to improve SiC through innovation of milling process. f Machinability of SiC composites.

[0009] Using laser irradiation to induce performance loss in local materials is an effective means to improve machinability. For common hard and brittle materials, when the material is locally heated by a focused laser beam, the apparent hardness can be reduced by up to 50%, which greatly expands the ductility domain of the material and is conducive to material removal in the ductility domain. However, silicon carbide has excellent high-temperature mechanical properties, and its high-temperature strength can even be maintained up to 1600°C. Therefore, within the temperature threshold range where high-temperature damage occurs, the temperature increase has a great impact on SiC. f The influence of strength loss of SiC composites is extremely limited, and the hardness reduction of silicon carbide at high temperature is also very small. f For SiC composites, the effect of softening the material by high temperature to improve the machinability is very limited, and laser heating assisted processing technology is not suitable for SiC f / SiC composite materials.

[0010] To solve the problem of SiC f The problem of extremely low processing efficiency of SiC composite materials urgently requires an efficient milling method to promote the large-scale application of SiC in the aerospace field. f / SiC composite materials provide technical reserves. Summary of the invention

[0011] In order to solve the problems existing in the prior art, the present invention provides a SiCf / SiC milling method and device based on laser induced ablation.

[0012] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0013] Laser-induced ablation of SiC f / SiC milling method, determine SiC f After the cutting allowance d of the / SiC composite material is removed, the laser induced ablation treatment is performed on it, so that the material to be removed with a surface thickness of d1 (laser induced ablation depth, including the thickness of the ablation product and the thickness of the heat-affected layer) becomes a powdered laser induced ablation product, which is then milled;

[0014] Laser induced ablation treatment uses a laser power density of 1.5×10 6 ~3.1×10 6 W / cm 2 The laser beam directly scans the SiC f / SiC composite surface;

[0015] During laser induced ablation, the value of d1 is adjusted by adjusting the laser parameters of the laser beam so that the value of d1 satisfies d-d2=d1. d2 is the minimum radial cutting width of the unaffected layer material to ensure that the ablation product and the heat-affected layer material are completely removed. The value range of d2 is 0.1-0.2 mm. The heat-affected layer is a layer of SiC that is not ablated during laser induced ablation but has its performance degraded due to the influence of temperature. f / SiC composite material, which is the laser-induced ablation product and the original SiC f / transition layer between SiC composite materials;

[0016] Laser-induced ablation of SiC f The milling time of the SiC milling method is reduced by 90% to 93% compared with the comparison method. f The difference between the / SiC milling method is that it does not perform laser-induced ablation;

[0017] The milling time of conventional milling (i.e., the comparative method) and the milling time of laser-induced ablation-assisted processing (i.e., the SiCf / SiC milling method based on laser-induced ablation of the present invention) can be respectively expressed by the following formulas:

[0018] Conventional milling:

[0019] Laser-induced ablation-assisted milling:

[0020] Where, t CM and t LAAM are the milling time of conventional milling and laser-induced ablation-assisted milling, respectively, in min; is the rounding function; d is the milling allowance, in mm; a w,max The maximum radial cutting width to meet the processing quality requirements, in mm; l m is the milling length, in mm; v f is the feed speed, in mm / min; t aux The necessary auxiliary time for rapid feed, retracting, etc., the unit is min; t LA is the laser induced ablation treatment time, in min;

[0021] It is worth noting that the laser induced ablation processing time is included in the calculation of the laser induced ablation assisted milling processing time; when processing a single part, this time needs to be calculated; but in the case of mass production, since the laser induced ablation processing and CNC processing can be carried out at the same time, that is, the current workpiece is undergoing laser induced ablation processing, but the previous workpiece that has been laser induced ablation processed is undergoing CNC processing; therefore, for such mass production, the laser induced ablation processing time can be excluded from the total time;

[0022] In general, the laser-induced ablation-assisted milling process can significantly improve SiC f The milling efficiency of / SiC composite materials is higher, and the larger the machining allowance and the more workpieces to be processed, the more obvious its advantages are.

[0023] The present invention uses a high energy density laser beam to directly irradiate SiC f The surface of the SiC composite material can cause high-temperature ablation of the material, resulting in a sharp loss of material properties in the layer to be processed, which is beneficial to the milling process and reduces the milling process time. The specific principle is:

[0024] When the laser beam irradiates the surface of the material, based on the photothermal effect, the material generates a high temperature of up to several thousand degrees Celsius in a very short time after absorbing the energy of the laser. When the temperature exceeds 2700℃, both the SiC fiber and the SiC matrix will sublimate to form SiC vapor. In the central area irradiated by the laser beam, photo-induced plasma will also be generated due to avalanche ionization. The remaining SiC vapor diffuses to both sides of the laser beam. When the SiC vapor comes into contact with the air, it will undergo an oxidation reaction with oxygen at high temperature. A part of the SiC vapor undergoes passive oxidation to produce pure gaseous products and dissipates, while the other part of the SiC vapor undergoes active oxidation to produce amorphous SiO2. Since the gaseous SiC reacts with oxygen at high temperature, the amorphous SiO2 particles produced by this gas phase reaction are extremely fine and appear in the form of smoke. During the laser-induced ablation process, the amorphous SiO2 smoke produced will adhere to the treated surface, so the surface of the ablated area will be raised compared to the untreated area. When the laser parameters are adjusted to increase the depth of laser ablation, the SiC vapor in the subsurface area of ​​the material is isolated from the air by the SiC vapor in the upper layer. Therefore, the SiC vapor in the subsurface lacks the necessary conditions for an oxidation reaction. During the rapid cooling process, the SiC vapor in the subsurface recrystallizes and regenerates SiC crystals. After the subsurface is formed, the recrystallized SiC is re-deposited on the subsurface of the ablated area. Since the recrystallized SiC is directly condensed from the gas phase, the size of the recrystallized SiC particles is only a few microns to tens of microns, and there are gaps between the particles. Since the laser beam moves forward, both the recrystallized SiC and the condensed SiO2 smoke are deposited in the ablated area.

[0025] Whether it is recrystallized SiC or SiO2 smoke, these ablation products are in the form of loose and porous powder. Compared with the high-hardness SiC fiber and SiC matrix, the powdered ablation products are very easy to remove, and the machinability is expected to be greatly improved.

[0026] The main purpose of laser induced ablation assisted milling technology is to achieve SiC f / Efficient milling of SiC composite materials. When removing materials with the required cutting allowance, if conventional milling is used, the maximum radial cutting width is very small under the premise that the process parameters are feasible and the processing quality is met. Therefore, it is necessary to pass the tool repeatedly many times to reach the cutting allowance, which greatly reduces the processing efficiency. By adopting the laser-induced ablation-assisted milling process, after determining the cutting allowance, most of the material to be removed can be converted into powdered laser-induced ablation products through laser-induced ablation. At the same time, by adjusting the laser parameters, only a small layer of unaffected layer material is left in the cutting allowance. The width of this unaffected layer material is the minimum radial cutting width of the unaffected layer material to ensure that the ablation products and the heat-affected layer material are completely removed. At this time, if the material is removed by milling, the cutting allowance can be achieved in one pass.

[0027] As the preferred technical solution:

[0028] As described above, the SiC f / SiC milling method, the laser beam forming process is: firstly, the laser is used to stably output continuous laser, then the deflection lens II is used to realize the primary deflection of the laser beam, then the deflection lens I is used to realize the secondary deflection of the laser beam, and finally the flat field lens is used to realize the focusing of the secondary deflected laser beam to form a laser beam.

[0029] As described above, the SiC f / SiC milling method, the wavelength of the laser output by the laser is 1064nm, the beam diameter is 7.0±0.5mm, and the beam quality factor M 2 <1.4, laser power P is 30-60W; the focal length of the flat-field lens is 254mm; the diameter of the laser spot after focusing is 50μm; these parameters make the laser power density of the formed laser beam 1.5×10 6 ~3.1×10 6 W / cm 2 .

[0030] As described above, the SiC f / SiC milling method, laser parameters include laser power P, scanning speed v laser and scanning line spacing l s , scanning speed v laser The value range is 10~40mm / s, and the scanning line spacing is l s The value range of is 5 to 20 μm. The form of the scanning path during laser induced ablation processing is not limited. The present invention only takes the "bow"-shaped scanning path as an example for explanation.

[0031] As described above, the SiC f / SiC milling method, the cutting edge material of the milling cutter used in the milling process is PCD (polycrystalline diamond), the front angle is 0°~5°, and the back angle is 8°~12°; the milling cutters that meet the limited conditions are applicable to the present invention, and the present invention only takes a two-edge straight groove PCD milling cutter as an example for explanation, the diameter of the milling cutter is 8mm, the front angle is 3°, and the back angle is 10°.

[0032] As described above, the SiC f / SiC milling method, after the milling process, SiC f The processed surface roughness Sa (surface roughness) of the SiC composite material is 0.8-1.2 μm, which shows that the method of the present invention can improve the processing efficiency without reducing the processing quality.

[0033] The present invention also provides a SiC based on laser induced ablation f / SiC milling device, including a generating device, an adjusting device, a fixture, a tool and a machine tool;

[0034] The generating device is used to form a laser power density of 1.5×10 6 ~3.1×10 6 W / cm 2 of laser beam;

[0035] The adjustment device is used to adjust the laser beam and SiC f The relative position of the SiC composite material makes the laser beam scan along a certain path on the SiC f / SiC composites;

[0036] The fixture is used to place SiC f / SiC composite materials are installed on machine tools;

[0037] Tools and machines for SiC f / SiC composite materials for milling.

[0038] As the preferred technical solution:

[0039] As described above, the SiC f / SiC milling device, the generating device includes a laser, an optical fiber, a scanning galvanometer and a flat field lens; the scanning galvanometer includes a deflection lens II and a deflection lens I.

[0040] As described above, the SiC f / SiC milling device, the adjustment device includes a control system, a scanning motor I and a scanning motor II, the scanning motor I is connected to the deflection lens I, the scanning motor II is connected to the deflection lens II, and the scanning motor I and the scanning motor II are connected to the control system at the same time; the working principle of the adjustment device is: the scanning motors I and II respectively control the deflection lenses I and II, and the reflection angle of the laser beam is controlled by the deflection angle of the lens, so as to realize the deflection of the laser beam in the X direction and the Y direction respectively, and through the coordinated control of the deflection in the two directions, the laser spot can be controlled to scan on the surface of the workpiece to be processed according to the set path;

[0041] The generating device and the adjusting device together constitute a scanning galvanometer system. The scanning galvanometer system used in the present invention is Xi'an Hezuoli Electromechanical Technology Co., Ltd., i10DBY; the basic working principle of the scanning galvanometer system is to deflect the light beam in the XY direction with the help of two deflection lenses and focus the light beam on the working surface; the light beam enters the scanning head through the input aperture, and is first reflected in the Y direction by the deflection lens I bound to the scanning motor, and then reaches the deflection lens II bound to the scanning motor to realize the deflection in the X direction; the deflection angle of the light beam can be accurately adjusted by controlling the position of the scanning motor through the control system, thereby controlling the scanning of the laser beam on the surface of the workpiece;

[0042] The structure of the generating device of the present invention is not limited to this, and other structures that can form a laser power density of 1.5×10 6 ~3.1×10 6 W / cm 2 The laser beam device is also applicable to the present invention;

[0043] The structure of the adjustment device of the present invention is not limited to this, and other devices capable of adjusting the laser beam and SiC f The relative position of the SiC composite material makes the laser beam scan along a certain path on the SiC f / SiC composite material is also applicable to the present invention. For example, the adjustment device can be a device mounted on SiC f / The moving device under the SiC composite material drives the SiC f / SiC composite material moves along a specific path to realize the scanning of the laser beam on the surface of the workpiece. The adjusting device can also be a moving device connected to the generating device. The moving device drives the generating device to move along a specific path to realize the scanning of the laser on the surface of the workpiece. When the structure of the adjusting device satisfies that it can constitute a scanning galvanometer system together with the generating device, it is most commonly used and convenient, and is therefore used as the preferred solution of the present invention.

[0044] Beneficial Effects

[0045] (1) The present invention is based on the laser induced ablation of SiCf / SiC milling method, significantly improving SiC f / Milling efficiency of SiC composites;

[0046] (2) SiC based on laser induced ablation of the present invention f / SiC milling device, simple equipment, good economy, can stably achieve SiC f Laser induced ablation processing of SiC / SiC composites. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Laser-induced ablation of SiC f / Schematic diagram of SiC milling device;

[0048] Figure 2 For SiC f Schematic diagram of the scanning path of the laser spot on the surface of the / SiC composite material;

[0049] Figure 3 Schematic diagram of laser induced ablation processing;

[0050] Figure 4 For SiC f / Front view of SiC composite material;

[0051] Figure 5 For SiC f / SiC composite material side view;

[0052] Among them, 1-laser, 2-optical fiber, 3-scanning galvanometer, 3.1-deflection lens I, 3.2-deflection lens II, 4-flat field lens, 5-control system, 6-laser beam, 7-SiC f / SiC composite material, 8-laser induced ablation product, 9-milling cutter. DETAILED DESCRIPTION

[0053] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0054] Laser-induced ablation of SiC f / SiC milling method, the specific process is as follows:

[0055] Determine SiC fAfter the cutting allowance d of the / SiC composite material is reduced, the laser induced ablation treatment is performed on it, so that the surface thickness of the material to be removed with a thickness of d1 is converted into a powdered laser induced ablation product, and then the milling process is performed on it;

[0056] Laser induced ablation is the process of directly scanning SiC with a laser beam. f / SiC composite material surface; wherein, the laser beam forming process is: firstly, the laser is used to stably output continuous laser, then the deflection lens II is used to realize the primary deflection of the laser beam, then the deflection lens I is used to realize the secondary deflection of the laser beam, and finally the flat field lens is used to realize the focusing of the secondary deflected laser beam to form a laser beam; wherein, the wavelength of the laser output by the laser is 1064nm, the beam diameter is 7.0±0.5mm, and the beam quality factor M 2 <1.4, laser power P is 30-60W; the focal length of the flat-field lens is 254mm; the diameter of the laser spot after focusing is 50μm;

[0057] During laser induced ablation, the value of d1 is adjusted by adjusting the laser parameters of the laser beam so that the value of d1 satisfies d-d2=d1. d2 is the minimum width of the unaffected layer material to ensure that the ablation product and the heat-affected layer material are completely removed. The value range of d2 is 0.1-0.2 mm. The heat-affected layer is a layer of SiC that is not ablated during laser induced ablation but has its performance degraded due to the influence of temperature. f / SiC composite material; wherein the laser parameters include laser power P, scanning speed v laser and scanning line spacing l s , scanning speed v laser The value range is 10~40mm / s, and the scanning line spacing is l s The value range is 5 to 20 μm;

[0058] The cutting edge material of the milling cutter used in milling is PCD (polycrystalline diamond), with a rake angle of 0° to 5° and a back angle of 8° to 12°. f The processed surface roughness Sa (surface roughness) of the SiC / SiC composite material is 0.8~1.2μm.

[0059] Laser-induced ablation of SiC f The milling time of the SiC milling method is reduced by 90% to 93% compared with the comparison method. f The only difference between the / SiC milling method is that it does not perform a laser-induced ablation process.

[0060] The device used in the above method is based on laser induced ablation of SiC f / SiC milling device, such as Figure 1 As shown, it includes a generating device, an adjusting device, a control system 5, a fixture, a tool and a machine tool;

[0061] The generating device comprises a laser 1, an optical fiber 2, a scanning galvanometer 3 and a flat field lens 4; the scanning galvanometer 3 comprises a deflection lens II 3.2 and a deflection lens I 3.1, and the generating device is used to form a laser power density of 1.5×10 6 ~3.1×10 6 W / cm 2 of laser beam;

[0062] The adjustment device includes a control system, a scanning motor I and a scanning motor II. The scanning motor I is connected to the deflection lens I 3.1, and the scanning motor II is connected to the deflection lens II 3.2. The scanning motor I and the scanning motor II are connected to the control system at the same time. The adjustment device is used to adjust the laser beam 6 and the SiC f The relative position of the SiC composite material 7 enables the laser beam 6 to scan along a certain path on the SiC f / SiC composite material 7;

[0063] The generating device and the adjusting device together constitute a scanning galvanometer system;

[0064] The fixture is used to place SiC f / SiC composite materials are installed on machine tools;

[0065] Tools and machines for SiC f / SiC composite materials for milling.

[0066] Now, combined with specific cases, how to use the above milling device to cut SiC f Specific instructions for milling of SiC composite materials:

[0067] (1) Preparation of SiC f / SiC composite materials, SiC f The shape of the / SiC composite material blank is rectangular, with dimensions of 150 mm (length) × 13 mm (width) × 4.5 mm (thickness);

[0068] (2) Set the goal, that is, SiC f / SiC composite material processing Figure 4 and Figure 5 The shape and size shown specifically require side milling to form dog-bone grooves on both sides of the part;

[0069] (3) Determine SiC f The cutting allowance d of / SiC composite material is 2.5 mm;

[0070] (4) Determine that the minimum radial cutting width d2 of the material without the affected layer is 0.2 mm;

[0071] (5) Setting SiC f The scanning path of the laser spot of the laser beam on the surface of the / SiC composite material is as follows Figure 2 As shown;

[0072] (6) Carry out parameter tests and measure the laser power P, scanning speed v laser and scanning spacing l s The laser-induced ablation depth d1 at 1000 nm;

[0073] (7) Based on the experimental results of step (6), the laser power P (56 W) and scanning speed v corresponding to d1 of 2.3 mm are determined. laser (13mm / s) and scanning distance l s (10 μm);

[0074] (8) Select SiC f The upper surface of the / SiC composite material blank is the surface to be processed;

[0075] (9) performing laser induced ablation on the surface to be processed according to the scanning path of step (5) and the parameters of step (7);

[0076] (10) Figure 3 As shown, the SiC f The workpiece 7 of SiC composite material is clamped on the machine tool, and the two-edge straight groove PCD milling cutter 9 is used to mill the surface to be processed, so as to remove the laser induced ablation product 8. The diameter of the milling cutter is 8mm, the front angle is 3°, the back angle is 10°, and the radial cutting width is a w The milling parameters are set as spindle speed n of 3000rpm and axial cutting depth a p The feed per tooth is 4.5 mm. z 10 μm / z;

[0077] (11) Select SiC f The lower surface of the / SiC composite material is the surface to be processed, and steps (9) to (10) are repeated.

[0078] After milling, SiC f The processed surface roughness Sa of the / SiC composite material is 1.2μm. It takes 43.15min for laser induced ablation and 5.44min for milling to process both sides.

[0079] Evaluation of SiC based on laser induced ablation compared with existing technologies fThe advantages of the SiC milling method are as follows:

[0080] If the side milling process is carried out directly without laser induced ablation, in order to ensure that the roughness Sa of the processed surface is not greater than 1.2μm, the radial cutting width a w It cannot exceed 0.2mm. Therefore, when side milling, the radial cutting width is set to 0.1mm for the first feed, and then the side milling is performed with a radial cutting width of 0.2mm. Set the spindle speed n to 3000rpm and the feed per tooth f z is 10μm / z, axial cutting depth a p The thickness of the part is 4.5 mm. Under this milling parameter, 13 passes are required to process one side of a part, and 26 passes are required to process both sides of a part. Therefore, if a part is directly processed by milling without using laser induced ablation, the required milling time is as long as 70.72 minutes.

[0081] Using the method of the present invention, it takes 43.15 minutes to perform laser induced ablation on a blank, and then perform side milling. Only one pass is required for one side of a part, and only two passes are required for both sides of a part to complete the processing. The time required for milling is 5.44 minutes, which is a significant reduction of 92.31% compared with the milling process without laser induced ablation. The total time required for laser induced ablation and side milling of a part is 48.59 minutes;

[0082] In contrast, the use of laser-induced ablation can reduce the total processing time of the sample by 31.29%. In addition, in the actual part production process, a higher-power continuous laser can be used to implement the laser-induced ablation process, thereby improving the ablation efficiency at the same ablation depth, thereby further reducing the laser-induced ablation time. In addition, the laser-induced ablation time can be further compressed during mass production. In general, the laser-induced ablation-assisted milling processing strategy can significantly improve processing efficiency.

Claims

1. SiC based on laser induced ablation f / SiC milling method, characterized in that Determine SiC f Cutting allowance of SiC composite materials d After that, it was subjected to laser induced ablation to make its surface thickness d 1. The material to be removed is converted into a powdered laser-induced ablation product, which is then milled; Laser induced ablation treatment uses a laser power density of 1.5×10 6 ~3.1×10 6 W / cm 2 The laser beam directly scans the SiC f / SiC composite surface; Laser induced ablation is regulated by adjusting the laser parameters of the laser beam d The value of 1 makes d The value of 1 satisfies d - d 2= d 1, d 2 The minimum radial cutting width of the unaffected layer material to ensure that the ablation products and the heat-affected layer material are completely removed, d The value range of 2 is 0.1~0.2mm. The heat-affected layer is a layer of SiC that is not ablated during laser-induced ablation but has performance degraded due to temperature. f / SiC composite materials; Laser-induced ablation of SiC f The milling time of the SiC milling method was reduced by 90% to 93% compared with the comparison method. f The only difference between the / SiC milling method is that it does not perform a laser-induced ablation process.

2. The SiC based on laser induced ablation according to claim 1 f / SiC milling method, characterized in that The laser beam formation process is as follows: first, the laser is used to stably output continuous laser light, then the deflection lens II is used to achieve the primary deflection of the laser beam, then the deflection lens I is used to achieve the secondary deflection of the laser beam, and finally the flat-field lens is used to focus the secondary deflected laser beam to form a laser beam.

3. The SiC based on laser induced ablation according to claim 2 f / SiC milling method, characterized in that The wavelength of the laser output by the laser is 1064nm, the beam diameter is 7.0±0.5mm, and the beam quality factor is M 2 <1.4, laser power P The power is 30~60W; the focal length of the flat-field lens is 254mm; the diameter of the laser spot after focusing is 50μm.

4. The SiC based on laser induced ablation according to claim 3 f / SiC milling method, characterized in that Laser parameters include laser power P , Scanning speed v laser and scan line spacing l s , scanning speed v laser The value range is 10~40mm / s, and the scanning line spacing l s The value range is 5~20μm.

5. The SiC based on laser induced ablation according to claim 1 f / SiC milling method, characterized in that The cutting edge material of the milling cutter used in milling processing is PCD, with a front angle of 0°~5° and a back angle of 8°~12°.

6. The SiC based on laser induced ablation according to claim 1 f / SiC milling method, characterized in that After milling, SiC f The processed surface roughness Sa of the / SiC composite material is 0.8~1.2μm.

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