A SiC f / SiC ceramic matrix composite flame tube and its outer surface processing method

Abstract

The application relates to the technical field of ceramic matrix composite material grinding processing, in particular to a SiC f / SiC ceramic matrix composite material flame tube and outer surface processing method, the machining radius and profile tolerance of the outer surface of the workpiece in or on the inner wall of the flame tube, the rotary indexing angle of grinding machining and the diameter of the grinding tool grinding head are obtained, and according to the diameter of the grinding tool grinding head, a suitable grinding tool is selected to perform ultrasonic vibration assisted grinding machining on the outer surface of the workpiece in or on the inner wall of the flame tube. Through the matching design of the rotary indexing angle and the diameter of the grinding tool grinding head, the application realizes self-adaptive optimization of process parameters, balances efficiency and precision, ensures the profile tolerance of the machined surface, improves machining quality and machining efficiency. Meanwhile, the ultrasonic vibration assisted grinding tool path is adopted to optimize grinding machining, which not only can improve machining quality, but also can prolong the service life of the tool, and solves the problem of low processing efficiency of the SiC f / SiC ceramic matrix composite material combustion chamber flame tube outer surface.

Description

Technical Field

[0001] This invention relates to the field of grinding technology for ceramic matrix composites, specifically a SiC... f / SiC ceramic matrix composite flame tube and its outer surface processing method. Background Technology

[0002] Silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC) f SiC (Silicon Carbide) is mainly composed of silicon carbide fibers and a silicon carbide matrix. It features low density, high temperature resistance, and high hardness, making it promising for applications in advanced aero-engine hot-section components. However, SiC... f The high hardness, brittleness, and non-uniformity of SiC ceramic matrix composites present challenges in machining, such as significant tool wear, difficulty in machining, and poor machinability.

[0003] Chinese invention patent CN117102982A discloses "A method for ultrasonic vibration-assisted grinding of ceramic matrix composites." This method obtains the critical depth of the micro-to-macro brittle fracture transition by conducting single-grain abrasive-based scratch tests; then, based on the critical depth of the micro-to-macro brittle fracture transition and the surface quality of the part, it obtains ultrasonic vibration-assisted grinding process parameters; finally, it performs ultrasonic vibration-assisted grinding of ceramic matrix composites based on these parameters, achieving improved grinding efficiency while ensuring high-quality surface finish of the ceramic matrix composites. However, in the field of aero-engines, high-temperature resistant SiC... f The inner and outer wall dimensions and shapes of the SiC ceramic matrix composite combustion chamber flame tube must match the engine and be lightweight. It adopts an annular thin-walled structure. The outer surface of its inner and outer walls is machined by conventional turning or grinding. The cutting tools are easily worn, and the surface quality after machining is poor and the machining efficiency is low. If only the above-mentioned single abrasive grain-based scratch test combined with ultrasonic vibration-assisted grinding method is used, although the machining quality and efficiency are improved, the problems of grinding head wear and low machining efficiency still cannot be overcome. Summary of the Invention

[0004] Addressing the existing SiC technology f To address the problem of low machining efficiency of the outer surface of the combustion chamber flame tube in SiC ceramic matrix composite materials, this invention provides a SiC... f / SiC ceramic matrix composite flame tube and its outer surface processing method.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention provides a SiC f / SiC ceramic matrix composite flame tube outer surface machining methods include:

[0007] Obtain the machining radius and profile requirements of the workpiece's outer surface inside or outside the flame tube;

[0008] Based on the machining radius and profile requirements of the workpiece's outer surface inside or outside the flame tube, obtain the grinding rotation angle;

[0009] The diameter of the grinding head and grinding tool is determined based on the rotational indexing angle of the grinding process.

[0010] Based on the diameter of the grinding head, select the appropriate grinding tool to perform ultrasonic vibration-assisted grinding on the outer surface of the workpiece inside or outside the flame tube.

[0011] Optionally, the axis of the grinding tool is perpendicular to the axis of the workpiece inside or outside the flame tube.

[0012] Optionally, the method for obtaining the grinding rotation pitch angle based on the machining radius and profile requirements of the workpiece's outer surface inside or outside the flame tube is as follows:

[0013] cos(α / 2) = R / (R+H)

[0014] F≤H≤F

[0015] Where α is the grinding rotation angle; R is the machining radius of the workpiece's outer surface inside or outside the flame tube; and F is the half profile value of the workpiece's inner or outer surface inside or outside the flame tube.

[0016] Optionally, the method for determining the diameter of the grinding head based on the grinding rotation angle is as follows:

[0017] ΦC = 2 × (A + B)

[0018] A = tan(α / 2) × R

[0019] Where ΦC is the diameter of the grinding tool head; 3mm≤B≤6mm; α is the grinding rotation angle; and R is the machining radius of the workpiece's outer surface inside or outside the flame tube.

[0020] Optionally, the grinding head of the grinding tool is a brazed diamond grinding head.

[0021] Optionally, the diamond abrasive grains on the brazed diamond grinding head have a particle size of 150 to 250 mesh.

[0022] Optionally, the value of the grinding rotation angle can be divisible by 360°.

[0023] Optionally, the grinding tool includes a clamping portion, the diameter ΦD of which satisfies: 6mm≤ΦD≤M(mm), where M is the maximum clamping diameter of the ultrasonic vibration grinding tool holder.

[0024] Optionally, the ultrasonic vibration-assisted grinding process has a grinding speed of 6000-11000 rpm / min, a feed rate of 1000-1500 mm / min, and a grinding depth of 0.05-0.1 mm; the ultrasonic vibration frequency is 28-38 kHz; and the amplitude of the grinding tool head is 4-8 μm.

[0025] The present invention also provides a SiC f The SiC ceramic matrix composite flame tube is processed using the aforementioned surface machining method.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention provides a SiC f A method for machining the outer surface of a SiC ceramic matrix composite flame tube involves obtaining the machining radius and profile requirements of the workpiece's outer surface inside or outside the flame tube; then, based on the machining radius and profile requirements, obtaining the grinding rotation angle; finally, determining the diameter of the grinding head based on the grinding rotation angle, and selecting a grinding tool to perform ultrasonic vibration-assisted grinding on the outer surface of the workpiece inside or outside the flame tube. By matching the rotation pitch angle and the grinding head diameter of the grinding tool, adaptive optimization of process parameters is achieved, balancing efficiency and accuracy, ensuring the contour accuracy of the machined surface, thus meeting the high-precision machining requirements of complex surfaces, improving machining quality and efficiency, and avoiding tool overload or ineffective machining caused by parameter mismatch. Simultaneously, ultrasonic vibration-assisted grinding tool path optimization not only reduces material micro-cracks and edge chipping, improving surface integrity, but also reduces grinding force and heat during the grinding process, reduces continuous contact between the grinding tool and the workpiece, reduces grinding head wear, extends service life, and reduces tool change frequency and machining costs. This method is simple and easy to operate, can be integrated into CNC machine tools, has strong compatibility, is suitable for mass production, and provides key technical support for the engineering application of advanced ceramic matrix composites.

[0028] The axis of the grinding tool is perpendicular to the axis of the workpiece inside or outside the flame tube. When the tool axis is perpendicular to the workpiece axis, the grinding force mainly acts along the normal direction of the workpiece surface, avoiding tool slippage or offset caused by lateral force, thereby significantly improving the surface profile accuracy and dimensional consistency. At the same time, perpendicular grinding ensures uniform stress in the contact area between the abrasive grains and the workpiece, reducing fiber breakage, matrix peeling, or microcrack propagation caused by local stress concentration, which is especially suitable for brittle SiC.f High surface integrity processing of SiC materials.

[0029] Based on the machining radius and profile requirements of the workpiece's outer surface inside or outside the flame tube, the method for obtaining the grinding rotation pitch angle is based on the circular envelope theory and the limitation of the residual height. This method directly transforms the profile into a geometric constraint for the grinding tool path planning, strictly binding the calculation of the pitch angle with the accuracy requirements. It also limits the radial deviation of the covered area in two adjacent grinding operations to the required range, thereby ensuring the stability of the final profile quality.

[0030] The method for determining the diameter of the grinding tool head based on the grinding rotation angle determines the diameter of the grinding tool head by using the grinding rotation angle and introduces redundancy to ensure that even if there are slight deviations in the theoretical calculation, the error can still be covered by the compensation amount. This ensures that the actual overlap of adjacent grinding trajectories always meets the design requirements and avoids stripe defects caused by insufficient overlap leading to unprocessed areas on the surface.

[0031] The grinding head of the grinding tool is a brazed diamond grinding head. Brazed diamond grinding heads have better wear resistance and longer service life. The brazed diamond abrasive grains have a high exposed height and less bonding agent covering the abrasive grains, which keeps the grinding edges of the abrasive grains sharp at all times, reduces grinding force, and minimizes damage to SiC. f Transverse shear damage of SiC fibers and propagation of microcracks in the matrix.

[0032] The diamond abrasive grains on the brazed diamond grinding head have a grit size of 150-250 mesh. This moderate grit size, combined with the reasonable depth of cut and grinding volume per grain, ensures a high material removal rate while avoiding deep grooves or surface chipping caused by excessively coarse abrasive grains. This design is particularly suitable for SiC. f High-efficiency processing of SiC.

[0033] The grinding rotation angle is divisible by 360°. When the grinding rotation angle is divisible by 360°, the grinding tool can fully cover the circumference when machining the outer surface of the workpiece inside or outside the flame tube. This ensures that the starting and ending points of each indexing are strictly coincident, avoiding surface ripples or overcutting caused by overlapping grinding. It also avoids unprocessed or repeatedly processed areas due to accumulated angle errors, ensuring the uniformity and accuracy of the machining.

[0034] The grinding tool includes a clamping part, the diameter ΦD of which satisfies: 6mm≤ΦD≤M(mm), where M is the maximum clamping diameter of the ultrasonic vibration grinding tool holder, so that the grinding tool can better match the processing equipment and ensure the stability of processing and the efficiency of energy transfer.

[0035] The ultrasonic vibration-assisted grinding process features a grinding speed of 6000–11000 rpm / min, a feed rate of 1000–1500 mm / min, and a grinding depth of 0.05–0.1 mm. The ultrasonic vibration frequency is 28–38 kHz, and the amplitude of the grinding head is 4–8 μm. Appropriate machining speed, feed rate, grinding depth, and ultrasonic vibration frequency, combined with precise grinding path and parameter settings, ensure machining quality while improving machining efficiency. Compared to traditional machining methods, efficiency is increased by 500%, while tool costs are reduced, achieving SiC… f The efficient and high-quality grinding of the outer surface of the inner or outer wall of the flame tube of SiC ceramic matrix composite material has promoted the breakthrough of precision machining technology for ceramic matrix composite components, and laid a certain technical foundation for promoting the engineering application of ceramic matrix composite materials.

[0036] A SiC f The SiC ceramic matrix composite flame tube is processed using the aforementioned surface machining method. f The SiC ceramic matrix composite flame tube features high-temperature stability, lightweight, high strength, efficient cooling, and long lifespan, providing key technical support for the high performance, high reliability, and long lifespan of aero-engines. Attached Figure Description

[0037] Figure 1 A SiC of the present invention f A flowchart illustrating the machining method for the outer surface of a SiC ceramic matrix composite flame tube.

[0038] Figure 2 A SiC of the present invention f A schematic diagram showing the tool path and grinding tool structure relationship during the machining process of the outer surface of the SiC ceramic matrix composite flame tube.

[0039] Figure 3 This is a schematic diagram of the structural shape of a workpiece on the inner wall of a flame tube.

[0040] Figure 4 This is a schematic diagram showing the tool path and grinding tool structure relationship in a specific embodiment of the present invention.

[0041] Among them, 1-grinding tool, 2-workpiece inside or outside the flame tube. Detailed Implementation

[0042] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0045] In the field of aero-engines, high-temperature resistant SiC is required. f The dimensions and shape of the inner or outer wall of the combustion chamber flame tube of SiC ceramic matrix composite material must match the engine and be lightweight. It adopts an annular thin-walled structure. The outer surface of its inner or outer wall is machined by conventional turning or grinding. The tools are easily worn, the surface quality after machining is poor and the machining efficiency is low.

[0046] To solve the above problems, see [link to relevant documentation]. Figure 1 This invention discloses a SiC f / SiC ceramic matrix composite flame tube outer surface machining methods include:

[0047] S1: Obtain the machining radius and surface profile requirements of the outer surface of workpiece 2 on the inner or outer wall of the flame tube, specifically:

[0048] By analyzing SiC f Based on the structural characteristics and processing requirements of the outer surface of the workpiece 2 on the inner or outer wall of the SiC ceramic matrix composite flame tube, select an appropriate machining center. For example, the outer wall of a flame tube is an annular thin-walled structure. The processing requirements are: surface roughness Ra≤3.2um, profile contour≤0.3mm, and no micro-cracks, tears, chipping, or delamination on the ground surface.

[0049] S2: Based on the machining radius and profile requirements of the outer surface of workpiece 2 inside or outside the flame tube, obtain the grinding rotation angle, specifically:

[0050] cos(α / 2) = R / (R+H)

[0051] (1 / 6)F≤H≤(1 / 4)F

[0052] Wherein, α is the grinding rotation angle; R is the machining radius of the outer surface of the workpiece 2 inside or outside the flame tube; F is the 1 / 2 profile value of the workpiece 2 inside or outside the flame tube; preferably, the grinding rotation angle is divisible by 360°.

[0053] S3: Determine the diameter of the grinding head for grinding tool 1 based on the grinding rotation angle, specifically:

[0054] ΦC = 2 × (A + B)

[0055] A = tan(α / 2) × R

[0056] Wherein, ΦC is the diameter of the grinding head of the grinding tool 1; 3mm≤B≤6mm; α is the grinding rotation angle; R is the machining radius of the outer surface of the workpiece 2 inside or outside the flame tube.

[0057] Preferably, the axis of the grinding tool 1 is perpendicular to the axis of the workpiece 2 inside or outside the flame tube; the grinding head of the grinding tool 1 is a brazed diamond grinding head, and the grit size of the diamond abrasive is 150-250 mesh. The grinding tool 1 includes a clamping part, and the diameter ΦD of the clamping part satisfies: 6mm≤ΦD≤M(mm), where M is the maximum clamping diameter of the ultrasonic vibration grinding tool holder.

[0058] See Figure 2 After determining the tool path and grinding tool structure parameters through S1 to S3, machining is performed as shown in the diagram, based on SiC. f Single abrasive scratch tests were conducted on SiC ceramic matrix composites to analyze the material removal fracture modes and removal mechanisms, combined with SiC... f Experiments were conducted on ultrasonic vibration-assisted grinding of SiC ceramic matrix composites to determine grinding parameters and to perform geometric simulation of the grinding process.

[0059] S4: Based on the diameter of the grinding head of grinding tool 1, select grinding tool 1 to perform ultrasonic vibration-assisted grinding on the outer surface of the workpiece 2 inside or outside the flame tube, specifically as follows:

[0060] Operate the machining center and assemble the ultrasonic vibration-assisted grinding device to the machining center. Correctly install and fix the special tooling on the machining center worktable, and then... fThe workpiece on the inner or outer wall of the / SiC ceramic matrix composite material is correctly positioned, clamped in a special tooling, and adjusted and placed in the processing position.

[0061] The cooling method selected during processing is SiC. f Water-based grinding fluid is used for cooling during the grinding of the outer surface of the workpiece 2, which is an inner or outer wall of SiC ceramic matrix composite material.

[0062] Operate the equipment to perform SiC f Grinding of the outer surface of workpiece 2, which is an inner or outer wall of SiC ceramic matrix composite material;

[0063] Based on the determined structural parameters of the grinding tool, select the correct diamond grinding head and install it on the ultrasonic grinding tool holder.

[0064] Turn on the power of the ultrasonic vibration-assisted grinding device. The frequency selection range for ultrasonic vibration is 28–38 kHz. Test the vibration state of the ultrasonic vibration device and detect the vibration amplitude of the grinding head. The vibration amplitude should be controlled within 4–8 μm. The grinding speed is 6000–11000 rpm / min, the feed rate is 1000–1500 mm / min, and the grinding depth is 0.05–0.1 mm.

[0065] Operate the machining center, set parameters, call the program, and complete the surface grinding process.

[0066] After completing the grinding of the inner wall surface, turn off the power to the ultrasonic vibration-assisted grinding system.

[0067] A SiC f The SiC ceramic matrix composite flame tube is processed using the aforementioned surface machining method. f The SiC ceramic matrix composite flame tube features high-temperature stability, lightweight, high strength, efficient cooling, and long lifespan, providing key technical support for the high performance, high reliability, and long lifespan of aero-engines.

[0068] Example 1

[0069] For further explanation of the technical solution of the present invention, please refer to [link / reference]. Figure 3 The image shows a schematic diagram of the shape of workpiece 2 on the inner wall of a flame tube. Its structural features include an annular, tapered, thin-walled structure with a wall thickness of 2.2 mm. Analysis of SiC... f Based on the structural characteristics and processing requirements of the outer surface of the SiC ceramic matrix composite flame tube inner wall test piece, the KMC800S-UMT milling and turning machining center was selected as the grinding equipment. Processing requirements: surface roughness ≤ Ra3.2um, profile contour ≤ 0.3mm, and no microcracks, tears, chipping, or delamination on the ground surface.

[0070] See Figure 4 The axis of the grinding tool is determined to be perpendicular to the axis of the workpiece 2 on the inner wall of the flame tube. The end face of the grinding tool 1 is used to grind the surface of the workpiece 2 on the inner wall of the flame tube.

[0071] Based on the machining radius of the outer circular surface of workpiece 2 on the inner wall of the flame tube and the surface profile requirements, the grinding rotation angle α is determined.

[0072] Given that the outer circle machining radius of workpiece 2 on the inner wall of the flame tube is R=204mm, and the profile tolerance value of 1 / 2 profile is F≤0.15mm.

[0073] The range of H is F≤H≤F, that is, 0.025mm≤H≤0.0375mm.

[0074] Using cos(α / 2)=R / (R+H), the rotational pitch angle α of the grinding process is calculated to satisfy 1.79°≤α≤2.197°, and α is taken as 2°, which is divisible by 360°.

[0075] Based on ΦC=2×(A+B), where: A=tan(α / 2)×R, 4mm≤B≤8mm, A=3.56mm, take B=6.44mm, determine the diameter of the grinding head of grinding tool 1 to be 20mm;

[0076] In order to be able to assemble and connect with the ultrasonic tool holder and to maintain a certain rigidity of the grinding tool 1, the diameter ΦD of the clamping part of the grinding tool 1 is determined to be 10mm.

[0077] Select grinding tool material: Select brazed diamond grinding head with 180-mesh diamond abrasive grains on the grinding head.

[0078] The determined grinding parameters are: rotational speed n = 7000 rpm / min; feed rate f = 1200 mm / min; grinding depth ap = 0.08 mm, and the grinding process is geometrically simulated.

[0079] Operate the machining center and assemble the ultrasonic vibration-assisted grinding device with the KMC800S-UMT milling and turning machining center. Correctly install and fix the special tooling on the machining center's worktable, and then... f The workpiece on the inner wall of the / SiC ceramic matrix composite material is correctly positioned, clamped in a special tooling, and adjusted and placed in the processing position.

[0080] Select cooling method: SiC f Water-based grinding fluid is used for cooling during the grinding of the outer circular surface of the inner wall of the SiC ceramic matrix composite material.

[0081] Operate the equipment to perform SiC f Grinding of the outer circular surface of the inner wall of SiC ceramic matrix composite material, specifically:

[0082] 1) Install the selected diamond grinding head onto the ultrasonic grinding tool holder.

[0083] 2) Turn on the power of the ultrasonic vibration-assisted grinding device and adjust the ultrasonic vibration frequency to 30kHz. Test the vibration state of the ultrasonic vibration device and the vibration amplitude of the grinding head of grinding tool 1. Adjust the tool overhang to keep the amplitude at 4μm.

[0084] 4) Operate the machining center, set parameters, call the program, and complete the surface grinding process.

[0085] 5) After completing the grinding of the second surface of the workpiece on the inner wall of the flame tube, turn off the power of the ultrasonic vibration assisted grinding system.

[0086] In this embodiment, SiC is analyzed. f Based on the structural characteristics and machining requirements of the inner wall surface of the SiC ceramic matrix composite flame tube, a KMC800S-UMT milling and turning machining center was selected. The tool path was rationally planned, and grinding tool 2 was determined. The following process parameters were used: spindle speed 7000 r / min, feed rate 1200 mm / min, grinding depth 0.08 mm, ultrasonic frequency 30 kHz, and ultrasonic amplitude 4 μm. Ultrasonic vibration grinding was employed to complete the grinding of the inner wall surface.

[0087] The results show that using the SiC of the present invention f A grinding method for the inner wall profile of a SiC ceramic matrix composite flame tube has been implemented. f High-efficiency, high-quality grinding of the outer circular surface of the inner wall of the SiC ceramic matrix composite flame tube. The grinding cycle time has been reduced from 120 minutes to 20 minutes, increasing processing efficiency by 500%.

[0088] In summary, this invention provides a SiC f A method for machining the outer surface of a SiC ceramic matrix composite flame tube was developed. By rationally planning the grinding path and tool structure parameters, and leveraging the advantages of ultrasonic vibration-assisted grinding, and selecting an appropriate ultrasonic amplitude, the grinding force, grinding heat, and tool wear were reduced during the grinding process, thus improving tool durability. Compared with traditional toolpaths, the machining efficiency was increased by 500%, while simultaneously reducing the cost of the grinding tool. The surface roughness and profile accuracy of the machined inner and outer walls met the design requirements. This method achieves SiC... f The efficient and high-quality grinding of the outer surface of the inner or outer wall of the SiC ceramic matrix composite flame tube has driven a breakthrough in the precision machining technology of ceramic matrix composite components, laying a certain technical foundation for promoting the engineering application of ceramic matrix composites.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A SiC f Method for machining the outer surface of a SiC include: Obtain the machining radius and profile requirements of the outer surface of the workpiece inside or outside the flame tube; Based on the machining radius and profile requirements of the outer surface of the workpiece (2) inside or outside the flame tube, the grinding rotation angle is obtained, specifically: cos(α / 2) = R / (R+H) (1 / 6)F≤H≤(1 / 4)F Where α is the grinding rotation angle; R is the machining radius of the outer surface of the workpiece (2) inside or outside the flame tube; F is the 1 / 2 profile value of the workpiece (2) inside or outside the flame tube. Based on the rotational indexing angle of the grinding process, determine the diameter of the grinding tool (1) and the grinding head, specifically: ΦC = 2 × (A + B) A = tan(α / 2) × R Wherein, ΦC is the diameter of the grinding tool (1) grinding head; 4mm≤B≤8mm; α is the grinding rotation angle; According to the diameter of the grinding head of the grinding tool (1), a suitable grinding tool (1) is selected to perform ultrasonic vibration-assisted grinding on the outer surface of the workpiece (2) inside or outside the flame tube; wherein, the axis of the grinding tool (1) is perpendicular to the axis of the workpiece (2) inside or outside the flame tube.

2. The SiC f A method of machining an outer surface of a SiC / SiC ceramic matrix composite flame tube, characterized by, The grinding head of the grinding tool (1) is a brazed diamond grinding head.

3. The SiC f A method of machining an outer surface of a SiC / SiC ceramic matrix composite flame tube, characterized by, The diamond abrasive grains on the brazed diamond grinding head have a particle size of 150-250 mesh.

4. The SiC f A method of machining an outer surface of a SiC / SiC ceramic matrix composite flame tube, characterized by, The rotational indexing angle of the grinding process is divisible by 360°.

5. The SiC f A method of machining an outer surface of a SiC / SiC ceramic matrix composite flame tube, characterized by, The grinding tool (1) includes a clamping part, the diameter ΦD of which satisfies: 6mm≤ΦD≤M(mm), where M is the maximum clamping diameter of the ultrasonic vibration grinding tool holder.

6. The SiC according to claim 1 f A method for machining the outer surface of a SiC ceramic matrix composite flame tube, characterized in that... The ultrasonic vibration-assisted grinding process has a grinding speed of 6000-11000 rpm / min, a feed rate of 1000-1500 mm / min, and a grinding depth of 0.05-0.1 mm; the frequency of ultrasonic vibration is 28-38 kHz; and the amplitude of the grinding head of the grinding tool (1) is 4-8 μm.

7. A SiC f / SiC ceramic matrix composite flame tube, characterized in that... The surface is processed using the surface processing method described in any one of claims 1-6.

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