Processing method, product and application of silicon carbide ceramic optical mechanical structure

Abstract

The invention relates to the technical field of silicon carbide ceramics, and discloses a machining method, a product and application of a silicon carbide ceramic optical mechanical structure, a round hole is formed in the middle of the silicon carbide ceramic optical mechanical structure, the silicon carbide ceramic optical mechanical structure comprises a plurality of hollow structures, and the machining method comprises the following steps: selecting a reference surface, and grinding the reference surface; milling and grinding the round hole, and then forming a plurality of matched round holes around the round hole to obtain a silicon carbide ceramic optical mechanical structure product; wherein the matched round hole is formed by electric spark breakdown of a matched reamer. According to the machining method, multiple machining modes are combined, the machining efficiency of the silicon carbide ceramic optical mechanical structure is improved, the problems that silicon carbide ceramic is high in hardness and large in brittleness during machining of a traditional tool are solved, and the quality, assembling performance and using performance of a machined silicon carbide ceramic optical mechanical structure product are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide ceramics, and in particular to a processing method, product and application of a silicon carbide ceramic optical mechanical structure. Background Art

[0002] Silicon carbide ceramics have good optical processing properties and can achieve excellent results through mechanical processing, making them widely used in optical reflectors and optical components. However, silicon carbide is a brittle material, and processing it with a tool can easily cause it to break, especially for high-precision and complex silicon carbide parts used in special scenarios. Due to the complexity of the structure, more special methods must be used during processing, and different processing methods need to be used according to different characteristics. At present, the processing of silicon carbide parts is difficult, inefficient, and has a high risk of damage. Summary of the invention

[0003] The present invention aims to improve at least one technical problem in the background technology.

[0004] A first aspect of the present invention provides a method for processing a silicon carbide ceramic optical mechanical structure, wherein a circular hole is formed in the middle of the silicon carbide ceramic optical mechanical structure, and the silicon carbide ceramic optical mechanical structure includes a plurality of hollow structures; the processing method includes the following steps: Selecting a reference surface, and grinding the reference surface; Milling the circular hole, and then forming a plurality of matching circular holes around the circular hole to obtain a silicon carbide ceramic optical mechanical structure product; The diameter of the circular hole is larger than the diameter of the matching circular hole; The matching circular hole is formed by using an electric spark puncture matching reamer.

[0005] The present invention first grinds the reference surface, and the reference surface is selected according to the following principles: (preferentially) the edge surface of the overall shape of the structure is selected as the reference surface, which is convenient for grinding positioning and subsequent processing reference; the reference surface (preferably) uses the smallest area plane to reduce the difficulty of grinding and ensure that the flatness is controllable; avoid selecting a large area plane, because it is easy to deform during grinding and it is difficult to ensure flatness; (preferentially) use a (multi-)region coplanar structure as a reference, and improve the stability of the reference through multi-point support. If a larger spatial range needs to be covered, select a continuous surface with a large span but the smallest area to balance the reference coverage and grinding controllability.

[0006] Grinding has the advantage of high precision. The ground reference surface can provide a common reference for the dimensional tolerance and form and position tolerance of the silicon carbide ceramic optical mechanical structure. After the middle circular hole of the optical mechanical structure is milled, electric spark breakdown is used in conjunction with a hole reamer to form a matching circular hole. The electric spark breakdown utilizes the conductive property of silicon carbide and breaks through the surface of the optical mechanical structure through high voltage electricity. The energy generated by the high voltage electricity allows a preliminary hole structure to be formed on the surface of the optical mechanical structure. Further, in conjunction with the use of a hole reamer, the cylindricity of the hole structure can be guaranteed while the hole is being expanded.

[0007] Beneficial effects of the invention: The invention improves the processing efficiency of silicon carbide ceramic optical mechanical structures by combining multiple processing methods, overcomes the problems of high hardness and brittleness of silicon carbide ceramics encountered in traditional tool processing, and improves the quality, assembly and use performance of the processed silicon carbide ceramic optical mechanical structure products.

[0008] Furthermore, after the reference surface is ground, the flatness of the reference surface is no greater than 0.005 mm.

[0009] Furthermore, before grinding the reference surface, the reference surface is rough-machined by milling. Grinding has a small removal amount, high precision but relatively low efficiency, and is suitable for high-precision finishing. Rough machining before grinding can further improve processing efficiency while ensuring precision.

[0010] Furthermore, the grinding is performed according to a preset overall removal amount; the grinding comprises the following steps: performing a first grinding on the reference surface, calculating a first removal amount, repeating the first grinding until the preset overall removal amount is met, and stopping to complete the grinding; the time for the first grinding is 10 minutes.

[0011] Excess material is gradually removed by step-by-step grinding, and the removal amount is calculated after each round of grinding to decide whether to continue the next round of grinding. This grinding method can effectively ensure the dimensional accuracy and surface quality of silicon carbide ceramic optical mechanical structures.

[0012] Furthermore, before milling the circular hole, the surface to be milled is reinforced, and the reinforcement process includes the following steps: designing and manufacturing an aluminum block according to the surface to be milled, placing the aluminum block at the hollow structure of the surface to be milled, fixing it, and completing the reinforcement process.

[0013] If the rigidity of the structure to be processed is poor, it is easy to break during the milling process, so reinforcement treatment is required. Specifically, the reinforcement treatment of the present invention adopts a structural repair method. An aluminum block is designed and manufactured according to the surface to be milled. When the aluminum block is placed, the annular surface of the aluminum block should be behind the surface to be milled to prevent the aluminum block from being milled. After the aluminum block is placed, it is fixed with hot melt adhesive. After milling is completed, the aluminum block is removed to complete the processing of the circular hole.

[0014] Further, the reamer includes a cone, a cone sleeve and a cone cap, a first cavity is formed in the cone sleeve, the first cavity matches the cone surface of the cone, the cone is inserted into the cone sleeve, a protruding end is formed at the front end of the cone, the protruding end extends out of the cone sleeve, a cone handle is formed at the rear end of the cone, the cone handle extends out of the cone sleeve, a second cavity is formed in the cone cap, the second cavity matches the protruding end, and the protruding end is inserted into the cone cap. After the reamer is inserted into the hole to be ground, the cone handle is pushed, the cone squeezes the cone sleeve to gradually deform the cone sleeve, and the hole to be ground is ground through the outer surface of the cone sleeve.

[0015] Furthermore, a plurality of first grooves are formed on the outer wall of the cone sleeve, and the first grooves are evenly arranged along the outer wall of the cone sleeve, and a plurality of second grooves are formed on the inner wall of the cone sleeve, and the second grooves are evenly arranged along the inner wall of the cone sleeve. The provision of the first grooves and the second grooves can ensure that the cone sleeve is uniformly deformed along the circumference, further improving the processing effect of the matching circular hole.

[0016] Preferably, the number of the first slots and the number of the second slots are both 3.

[0017] Furthermore, the protruding end is provided with a thread, and the inner wall of the cone cap is provided with a thread groove, and the thread matches the thread groove. The protruding end is gradually inserted into the cone cap by twisting the cone handle, and the cone squeezes the cone sleeve to gradually deform the cone sleeve. This arrangement makes the reamer more convenient to use and has a better processing effect on the matching circular hole.

[0018] A second aspect of the present invention provides a silicon carbide ceramic optomechanical structure product, which is obtained according to the above-mentioned processing method.

[0019] A third aspect of the present invention provides the use of the above silicon carbide ceramic optical mechanical structure product as an optical element. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 A schematic diagram of a silicon carbide ceramic optical mechanical structure according to an embodiment of the present invention; Figure 2A schematic diagram of reference plane selection for a silicon carbide ceramic optical mechanical structure according to an embodiment of the present invention; Figure 3 It is a schematic diagram of the structure of the reamer according to the embodiment.

[0021] In the accompanying drawings: 1-circular hole; 2-matching circular hole; 31-upper reference surface; 32-side reference surface; 33-lower reference surface; 4-surface to be milled; 5-hollow structure; 61-cone; 611-cone handle; 612-protruding end; 62-cone sleeve; 621-first groove; 622-second groove; 63-cone cap. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0025] Combine the following Figures 1 to 3 Embodiments of the present invention are described.

[0026] The embodiment of the present invention provides a method for processing a silicon carbide ceramic optical mechanical structure (especially a precision silicon carbide ceramic optical mechanical structure), referring to Figure 1 ( Figure 1 a and b are respectively the front and back sides of the silicon carbide ceramic optical mechanical structure). In this embodiment, a circular hole 1 is formed in the middle of the (precision) silicon carbide ceramic optical mechanical structure, and the silicon carbide ceramic optical mechanical structure includes a plurality of hollow structures 5. The processing method includes the following steps: Select a reference surface and grind the reference surface; The circular hole 1 is milled, and then three matching circular holes 2 are formed around the circular hole to obtain a (precision) silicon carbide ceramic optical mechanical structure product.

[0027] The diameter of the circular hole 1 is larger than the diameter of the matching circular hole 2; The matching circular hole 2 is formed by electric spark breakdown and a matching hole expander.

[0028] Reference Figure 2 ( Figure 2 In the figure, a and b are schematic diagrams of selecting the reference planes on the front and back sides of the silicon carbide ceramic optical mechanical structure respectively). In this embodiment, the reference plane is selected as the edge surface of the overall shape of the (precision) silicon carbide ceramic optical mechanical structure. The selected reference planes include an upper reference plane 31, a side reference plane 32 and a lower reference plane 33.

[0029] In this embodiment, the reference surface is rough-machined by milling before grinding. The removal amount of grinding is small, the precision is high but the efficiency is relatively low, which is suitable for high-precision finishing. In this embodiment, rough machining is performed before grinding, which can further improve the processing efficiency while ensuring the precision.

[0030] In this embodiment, fine sand is first sprinkled on the grinding table during grinding, and after being stirred with alcohol, the (precision) silicon carbide ceramic optical mechanical structure to be processed is placed on the grinding table for grinding.

[0031] At the same time, this embodiment adopts a step-by-step grinding method, first grinding the upper reference surface 31 and the side reference surface 32. Since the (precision) silicon carbide ceramic optical mechanical structure of this embodiment is a symmetrical structure of 3×120°, one of the corners is ground first during grinding, and one of the corners is fixed and ground on the grinding table for 10 minutes. To ensure the symmetry of the structure, after the first corner is ground for 10 minutes, the other corner is fixed and ground, and the same grinding is performed for 10 minutes. Finally, the last corner is fixed and ground. After one round is completed, the overall thickness of the optical mechanical structure is measured, and after the removal amount is calculated, a new round of grinding is performed according to the overall removal amount. The grinding of the lower reference surface 33 is similar.

[0032] After the reference surfaces are ground in this embodiment, the flatness of all reference surfaces is 0.005 mm.

[0033] The (precision) silicon carbide ceramic optical mechanical structure of this embodiment has a high light weight ratio and poor rigidity, and is easily broken during the milling process of the circular hole. Therefore, reinforcement treatment is required before the milling of the circular hole 1.

[0034] The reinforcement treatment of this embodiment adopts the method of repairing the structure, and the reinforcement treatment includes the following steps: designing and making an aluminum block according to the surface 4 to be milled, placing the aluminum block at the hollow structure 5 of the surface 4 to be milled, fixing it, and completing the reinforcement treatment. When the aluminum block is placed, the annular surface of the aluminum block should be behind the surface 4 to be milled to prevent the aluminum block from being milled; after placing the aluminum block, fix it with hot melt adhesive; after milling, soak it in acetone, remove the aluminum block after the adhesive softens, and complete the processing of the circular hole 1.

[0035] Further, refer to Figure 3 ( Figure 3 In the figure, a is a schematic diagram of the reamer structure, and b is a cross-sectional view of the reamer). In this embodiment, the reamer includes a cone 61, a cone sleeve 62 and a cone cap 63. The cone sleeve 62 is provided with a first cavity, which matches the cone surface of the cone 61. The cone 61 is inserted into the cone sleeve 62. A protruding end 612 is formed at the front end of the cone 61, and the protruding end 612 extends out of the cone sleeve 62. A cone handle 611 is formed at the rear end of the cone 61, and the cone handle 611 extends out of the cone sleeve 62. A second cavity is provided in the cone cap 63, which matches the protruding end 612, and the protruding end 612 is inserted into the cone cap 63. A thread (not shown in the figure) is provided on the protruding end 612, and a thread groove (not shown in the figure) is provided on the inner wall of the cone cap 63, and the thread matches the thread groove. In this embodiment, a hole structure is initially formed at a preset position of the circular hole 2 on the surface of the optical mechanical structure of silicon carbide ceramics by electric spark breakdown, and then the reamer is inserted, and the protruding end 612 is gradually inserted into the cone cap 63 by twisting the cone handle 611. At the same time, the first cavity matches the cone surface of the cone 61. When the cone 61 is pushed inward, its cone surface squeezes the cone sleeve 62 to gradually deform the cone sleeve 62, and then the hole structure is ground through the outer surface of the cone sleeve 62. In this embodiment, the cone 61 is pushed inward by screwing in a thread. Compared with the method of pushing in by a linear drive, the design of the corresponding thread in this embodiment can guide the cone 61 to advance evenly. Combined with the pitch characteristics in the thread design, the rotational motion of the cone 61 can be converted into a precise linear displacement. Each rotation can correspond to a fixed feed amount, which is more suitable for the processing (especially precision processing) of high-hardness brittle materials such as silicon carbide ceramics, avoiding the risk of overshoot caused by system inertia such as linear drives.

[0036] Among them, three first grooves 621 are formed on the outer wall of the cone sleeve 62, and the first grooves 621 are evenly arranged around the outer wall of the cone sleeve 62. Three second grooves 622 are formed on the inner wall of the cone sleeve 62, and the second grooves 622 are evenly arranged around the inner wall of the cone sleeve 62. In this embodiment, the arrangement of the first grooves 621 and the second grooves 622 evenly distributed in the circumferential direction can disperse the stress generated when the cone 61 pushes inward to squeeze the cone sleeve 62, so that the cone sleeve 62 generates uniform elastic deformation along the circumference when subjected to force, thereby avoiding uneven deformation caused by local stress concentration, and further improving the processing effect of the matching circular hole 2.

[0037] In general, the processing method of the (precision) silicon carbide ceramic optical mechanical structure provided in this embodiment, after selecting the reference surface, firstly uses the milling method to rough-process the reference surface in order to improve the processing efficiency, and then uses the step-by-step grinding method to ensure the flatness of the reference surface, which provides a high-precision dimensional reference for subsequent processing; before the milling of the circular hole 1, an aluminum block is placed at the hollow structure 5 of the surface 4 to be milled for reinforcement to prevent the silicon carbide ceramic optical mechanical structure from breaking during the milling process, and the aluminum block is removed after the milling is completed; finally, the conductive property of silicon carbide is utilized, and the hole structure is initially formed on the surface of the silicon carbide ceramic optical mechanical structure in conjunction with the preset position of the circular hole 2 by electric spark breakdown, and the hole structure is further ground with a specific reamer to complete the processing. The processing method of the (precision) silicon carbide ceramic optical mechanical structure provided in this embodiment improves the processing efficiency of the (precision) silicon carbide ceramic optical mechanical structure, and improves the quality, assembly and use performance of the (precision) silicon carbide ceramic optical mechanical structure product obtained by processing.

[0038] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A method for processing a silicon carbide ceramic optical mechanical structure, characterized in that: A circular hole is formed in the middle of the silicon carbide ceramic optical mechanical structure, and the silicon carbide ceramic optical mechanical structure includes a plurality of hollow structures; the processing method includes the following steps: Selecting a reference surface of the silicon carbide ceramic optical mechanical structure, and grinding the reference surface; Milling the circular hole, and then forming a plurality of matching circular holes around the circular hole to obtain a silicon carbide ceramic optical mechanical structure product; The diameter of the circular hole is larger than the diameter of the matching circular hole; The matching circular hole is formed by using an electric spark puncture matching reamer.

2. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 1, characterized in that: After the reference surface is ground, the flatness of the reference surface is no greater than 0.005 mm.

3. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 1, characterized in that: The grinding is performed according to a preset total removal amount; the grinding comprises the following steps: The reference surface is ground for the first time, a first removal amount is calculated, the first grinding is repeated until the preset total removal amount is met, and the grinding is completed; the time for the first grinding is 10 minutes.

4. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 1, characterized in that: Before the circular hole is milled, the surface to be milled is reinforced, and the reinforcement process includes the following steps: An aluminum block is designed and manufactured according to the surface to be milled, and the aluminum block is placed at the hollow structure of the surface to be milled and fixed to complete the reinforcement process.

5. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 1, characterized in that: The reamer includes a cone, a cone sleeve and a cone cap. The cone sleeve is provided with a first cavity, the first cavity matches the cone surface of the cone, the cone is inserted into the cone sleeve, the front end of the cone is formed with a protruding end, the protruding end extends out of the cone sleeve, the rear end of the cone is formed with a cone handle, the cone handle extends out of the cone sleeve, the cone cap is provided with a second cavity, the second cavity matches the protruding end, and the protruding end is inserted into the cone cap.

6. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 5, characterized in that: A plurality of first grooves are formed on the outer wall of the cone sleeve, and the first grooves are evenly arranged around the outer wall of the cone sleeve. A plurality of second grooves are formed on the inner wall of the cone sleeve, and the second grooves are evenly arranged around the inner wall of the cone sleeve.

7. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 6, characterized in that: The number of the first slots and the number of the second slots are both 3.

8. The method for processing a silicon carbide ceramic optical mechanical structure according to claim 6, characterized in that: The protruding end is provided with a thread, and the inner wall of the cone cap is provided with a thread groove, and the thread matches the thread groove.

9. A silicon carbide ceramic optical mechanical structure product, characterized in that: The silicon carbide ceramic optical mechanical structure product is obtained by the processing method according to any one of claims 1-8.

10. Use of the silicon carbide ceramic optical mechanical structure product as claimed in claim 9 as an optical element.

Images