A special-shaped ceramic cover plate and a preparation method and application thereof

Abstract

The present application relates to a kind of special-shaped ceramic cover plate and its preparation method and application, belong to electronic equipment technical field.The preparation method of special-shaped ceramic cover plate described in the present application is by using the process method of specific inner cavity and shape CNC rough machining, rough polishing and CNC finishing, and the specific inner cavity and shape CNC rough machining are respectively using specific profiled fixture and zirconia ceramic blank to be fixed, can make the fixed reference surface of the present application and special-shaped structure better fixed, to improve the adaptability between each process step, reach better appearance effect, to improve the surface processing quality of special-shaped ceramic cover plate, and the preparation method of special-shaped ceramic cover plate described in the present application, can effectively reduce production cost, can be used for mass production, with wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic equipment, and in particular relates to a special-shaped ceramic cover plate and a preparation method and application thereof. Background Art

[0002] With the development of society, economy, and technology, people's requirements for consumer electronics are gradually increasing, especially for product appearance and user experience. Ceramic mobile phones and other electronic products with curved back shell structures are increasingly popular due to their smooth touch, comfortable grip, and smooth appearance. However, existing ceramic cover plates are generally flat or 2.5D, with severe homogeneity and lack of novelty, which makes it difficult to meet people's demand for high-quality product appearance.

[0003] The typical 3D ceramic back cover production process is: machining - large surface roughing - large surface grinding - CNC internal shaping - CNC external shaping - medium polishing - CNC finishing - fine polishing - silk screen printing / PVD - AF. Because typical 3D back covers have large flat surfaces, roughing and grinding can be used to quickly remove grinding wheel marks. However, 5D special-shaped back covers lack large flat surfaces, making these processes impractical. Therefore, the back cover's shape and surface finish must be achieved entirely through CNC machining and polishing. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a special-shaped ceramic cover plate with good surface processing quality, low cost and suitable for mass production, as well as a preparation method and application thereof.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a method for preparing a special-shaped ceramic cover plate, comprising the following steps:

[0007] S1. Roughly trimming the shape of the blank of the special-shaped ceramic cover plate;

[0008] S2. Fit and fix the outer surface of the blank to the contour-copying fixture, and perform CNC rough machining of the inner surface of the blank;

[0009] S3, the inner surface of the blank is fitted and fixed with the imitation fixture of the inner cavity, and the outer surface of the blank is subjected to CNC rough machining of the shape;

[0010] S4, rough polishing the inner and outer surfaces of the blank and annealing;

[0011] S5, performing CNC finishing on the inner and outer surfaces of the blank respectively;

[0012] S6. Performing intermediate polishing and fine polishing on the outer surface of the blank to obtain the special-shaped ceramic cover plate.

[0013] The inventors of the present invention have discovered that by using the method for preparing the special-shaped ceramic cover plate of the present invention, the rough shape of the special-shaped ceramic cover plate is directly subjected to CNC rough machining of the inner cavity and CNC rough machining of the outer shape after the rough shape of the blank is roughly trimmed. In addition, the CNC rough machining of the inner cavity and the outer shape respectively uses a specific imitation fixture to fit and fix the blank of the special-shaped ceramic cover plate. This can make the fixed reference surface of the present invention better fit and fix with the special-shaped structure, thereby facilitating the CNC rough machining of the inner cavity and the outer shape, and achieving a better appearance effect. In addition, because the special-shaped structure has more curved surfaces, its effective support plane is smaller. Using the traditional 3D cover plate preparation method, using a large plane as the reference surface for CNC rough machining cannot effectively fix and support the special-shaped structure, and thus cannot achieve the appearance effect of the special-shaped back cover.

[0014] As a preferred embodiment of the preparation method of the special-shaped ceramic cover plate described in the present invention, in the step S1, the step of rough trimming the shape is: first use a long-side processing fixture to clamp the short side of the blank to expose the long side of the blank, and send the blank into a double-end grinder through a large disc to grind the long side of the blank, and process it twice to the target size; after the long side processing is completed, use a short-side processing fixture to clamp the long side of the blank to expose the short side of the blank, and send the blank into a double-end grinder through a large disc to grind the short side of the blank, and process it twice to the target size.

[0015] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S2, the step of CNC rough processing of the inner cavity is: the outer surface of the blank is fitted with the profiling fixture of the outer shape, and fixed by vacuum adsorption. Before opening the vacuum, the blank is finely positioned using an "L"-shaped positioning block, and then the CNC machine tool uses a contact probe to finely position the material. After positioning is completed, the CNC machine tool is used to grind the inner cavity shape of the blank according to the preset CNC rough processing program of the inner cavity.

[0016] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.1-0.2 mm, and the spacing between the tools of the CNC rough machining of the inner cavity is 0.2-1 mm.

[0017] The inventors of the present invention have conducted extensive research on the CNC rough machining process for inner cavities. By adopting the above-mentioned CNC rough machining removal amount and the CNC rough machining tool spacing range of the present invention, the CNC rough machining process for inner cavities has a high degree of compatibility with the processing of special-shaped structures, which can improve the surface processing quality of the special-shaped ceramic cover plate of the present invention and facilitate the removal of knife marks, while also increasing the service life of the tool. However, when the CNC rough machining removal amount and the tool spacing of the inner cavity are both high, it will cause severe tool wear, and various appearance defects will appear and the knife marks will not be removed by subsequent rough polishing, resulting in poor surface processing quality. When the CNC rough machining removal amount and the tool spacing of the inner cavity are both low, although the surface processing quality can be improved, it will lead to excessively long processing time, thereby increasing costs and being unfavorable for mass production.

[0018] As a more preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.15 mm, and the spacing between the tools of the CNC rough machining of the inner cavity is 0.8 mm.

[0019] The inventors of the present invention have found that the use of the above-mentioned CNC rough machining of the inner cavity and the spacing of the tools can make the CNC rough machining of the inner cavity more compatible with the machining of the special-shaped structure described in the present invention, and can enhance the surface machining quality of the special-shaped ceramic cover plate described in the present invention.

[0020] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S2, the tool for CNC rough machining of the inner cavity is an electroplated diamond grinding rod, the mesh number of the electroplated diamond grinding rod is 80 to 130 meshes, the diameter of the electroplated diamond grinding rod is 10 to 12 mm, the rotation speed of the electroplated diamond grinding rod is 18000 to 22000 r / min, and the machining dimensional accuracy requirement is ±0.05 mm.

[0021] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S3, the step of CNC rough processing of the outer shape is: the inner surface of the blank is fitted and fixed to the imitation fixture of the inner cavity, and fixed by vacuum adsorption. Before opening the vacuum, the blank needs to be roughly positioned using an "L"-shaped positioning block, and then the CNC machine tool uses a contact probe to finely position the material. After positioning is completed, the CNC machine tool is used to grind the outer shape of the blank according to the preset CNC rough processing program of the outer shape.

[0022] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.15-0.3 mm, and the spacing between the tools of the CNC rough machining of the outer shape is 0.1-0.25 mm.

[0023] The inventors of the present invention have conducted extensive research on the CNC rough machining process for external shapes. Using the CNC rough machining removal amount and tool spacing range described above, the CNC rough machining process for external shapes is highly compatible with the machining of special-shaped structures, making it suitable for mass production. It can also improve the surface machining quality of the special-shaped ceramic cover plate described in the present invention, facilitate the removal of knife marks, and improve the service life of the tool. However, when both the removal amount and tool spacing for CNC rough machining of external shapes are high, severe tool wear can occur, resulting in various appearance defects and the inability to remove knife marks through subsequent rough polishing, resulting in poor surface machining quality. When both the removal amount and tool spacing for CNC rough machining of external shapes are low, while surface machining quality can be improved, machining time can be excessively long, increasing costs and making it unsuitable for mass production.

[0024] As a more preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.25 mm, and the spacing between the tools of the CNC rough machining of the outer shape is 0.18 mm.

[0025] The inventors of the present invention have found that the use of the above-mentioned CNC rough machining of the shape of the present invention for the removal amount and the spacing of the tools can make the CNC rough machining of the shape more compatible with the machining of the special-shaped structure of the present invention, and can enhance the surface machining quality of the special-shaped ceramic cover plate of the present invention.

[0026] As a preferred embodiment of the preparation method of the special-shaped ceramic cover plate described in the present invention, the tool for CNC rough machining of the outer shape is an electroplated diamond grinding rod, the mesh number of the electroplated diamond grinding rod is 130-200 mesh, the diameter of the electroplated diamond grinding rod is 10-12 mm, the rotation speed of the electroplated diamond grinding rod is 18000-22000 r / min, and the processing size accuracy requirement is ±0.05 mm.

[0027] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in step S4, the material of the rough polishing disc is silicon carbide, and the rough polishing time is 1000 to 2000 seconds.

[0028] The inventors of the present invention have found that compared with traditional large-surface grinding processing methods, the rough polishing method described in the present invention can not only improve the compatibility of the rough polishing process with CNC rough machining of the inner cavity and CNC rough machining of the outer shape, but also better cooperate with the machining tool path of the full curved surface of the special-shaped structure, thereby solving the problem that multiple curved surfaces of the special-shaped structure cannot be ground using large flat surfaces. The use of the polishing disk made of silicon carbide described in the present invention for rough polishing can also quickly remove the knife marks of CNC rough machining of the inner cavity and CNC rough machining of the outer shape, thereby achieving a better appearance effect and reducing the cost of polishing.

[0029] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S4, the annealing temperature is 1100-1200°C, and the annealing time is 15-25 hours. The annealing method of the present invention can remove the stress on the inner and outer surfaces of the zirconia ceramic blank.

[0030] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, the difference between the step of CNC finishing the inner surface of the blank in step S5 and the CNC rough machining of the inner cavity of the inner surface of the blank in step S2 is that: the inner surface and outer surface of the blank are ground separately according to a preset CNC finishing program using a CNC numerical control machine tool; the difference between the step of CNC finishing the outer surface of the blank and the CNC rough machining of the outer shape of the outer surface of the blank in step S3 is that: the inner surface and outer surface of the blank are ground separately according to a preset CNC finishing program using a CNC numerical control machine tool.

[0031] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in step S5, the machining removal amount of the CNC finishing is 0.15-0.3 mm, and the spacing between the tools of the CNC finishing is 0.01-0.1 mm.

[0032] As a more preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in step S5, the CNC finishing tool is an electroplated diamond grinding rod, the mesh number of the electroplated diamond grinding rod is 200-380 meshes, the diameter of the electroplated diamond grinding rod is 10-12 mm, and the rotation speed of the electroplated diamond grinding rod is 18000-22000 r / min.

[0033] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S6, the material of the polishing disk for the medium polishing is pig hair, and the polishing time of the medium polishing is 1000 to 2000 seconds. The medium polishing of the present invention can remove deep scratches on the surface after rough polishing.

[0034] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S6, the material of the polishing disk for fine polishing is white grinding leather, and the polishing time of the fine polishing is 1000 to 2000 seconds. The fine polishing of the present invention can remove shallow scratches on the surface after medium polishing.

[0035] As a preferred embodiment of the preparation method of the special-shaped ceramic cover plate described in the present invention, it also includes step S7, which is: the outer surface of the special-shaped ceramic cover plate described in step S6 is subjected to laser engraving, silk screen printing and coating in sequence. By subjecting the outer surface of the special-shaped ceramic cover plate to the above-mentioned surface treatments in sequence, the appearance of the special-shaped ceramic cover plate can be beautified, and the special-shaped ceramic cover plate can also be designed and prepared according to different appearance requirements.

[0036] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, in the step S7, the laser power of the laser engraving is 20 to 50 W, and the laser engraving of the present invention is used to process a specific pattern or texture on the surface of the zirconia ceramic cover plate.

[0037] As a preferred embodiment of the method for preparing the special-shaped ceramic cover plate of the present invention, the special-shaped ceramic cover plate is a special-shaped zirconia ceramic cover plate.

[0038] In a second aspect, the present invention provides a special-shaped ceramic cover plate obtained by a method for preparing the above-mentioned special-shaped ceramic cover plate.

[0039] By adopting the preparation method of the special-shaped ceramic cover plate of the present invention, the special-shaped cover plate with a variety of complex shapes can be obtained, which has good visual effects, can not only meet the high-quality appearance requirements, but also can effectively reduce production costs, can be used for mass production, and has broad application prospects.

[0040] In a third aspect, the present invention provides an application of the above-mentioned special-shaped ceramic cover plate in preparing a special-shaped back cover of an electronic product.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The present invention adopts a specific CNC rough machining, rough polishing and CNC fine machining process for the inner cavity and outer shape, and the CNC rough machining of the inner cavity and outer shape respectively adopts a specific imitation fixture to fit and fix the blank of the special-shaped ceramic cover plate, which can make the fixed reference surface of the present invention fit and fix the special-shaped structure better, thereby facilitating the improvement of the adaptability between each process step, achieving a better appearance effect, and thus improving the surface processing quality of the special-shaped ceramic cover plate;

[0043] (2) The preparation method of the special-shaped ceramic cover plate of the present invention can obtain special-shaped cover plates with various complex shapes, which have good visual effects and can not only meet the high-quality appearance requirements, but also effectively reduce production costs, can be used for mass production, and have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is the appearance diagram of the special-shaped ceramic cover plate of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions of the present invention are further described below in conjunction with the embodiments and accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The methods or operations used in the embodiments, unless otherwise specified, are conventional methods or routine operations in the art.

[0046] The appearance of the special-shaped ceramic cover plates of the following embodiments 1 to 5 and comparative examples 1 to 5 of the present invention are shown in FIG. Figure 1 shown.

[0047] Example 1

[0048] An embodiment of the special-shaped ceramic cover plate of the present invention, wherein the method for preparing the special-shaped ceramic cover plate of this embodiment comprises the following steps:

[0049] S1. Use a double-end grinder to roughly trim the shape of the blank of the special-shaped zirconia ceramic cover plate. First, use a long-side processing fixture to clamp the short side of the blank to expose the long side of the blank, and feed the blank into the double-end grinder through a large disc. Grind the long side of the blank with a processing amount of 0.5mm / time. The target size is achieved after two processings. The dimensional processing accuracy is ±0.04mm. The mesh number of the grinding wheel used for processing is 100 mesh. After the long side processing is completed, use a short-side processing fixture to clamp the long side of the blank to expose the short side of the blank. Grind the short side of the blank with a processing amount of 0.5mm / time. The target size is achieved after two processings. The dimensional processing accuracy is ±0.04mm. The mesh number of the grinding wheel used for processing is 100 mesh.

[0050] S2. Fit the outer surface of the blank to the profiling fixture of the shape and fix it by vacuum adsorption. Before opening the vacuum, use an "L"-shaped positioning block to fine-tune and roughly position the blank. Then use a CNC machine tool to fine-position the material using a contact probe. After positioning, use the CNC machine tool to grind the inner cavity shape of the blank according to the preset CNC rough machining program of the inner cavity. The tool for CNC rough machining of the inner cavity is an electroplated diamond grinding rod, the mesh number of the electroplated diamond grinding rod is 100 mesh, the diameter of the electroplated diamond grinding rod is 11 mm, and the program for CNC rough machining of the inner cavity is as follows: the machining removal amount is 0.15 mm, the spacing between the tools for CNC rough machining of the inner cavity is 0.8 mm; the rotation speed of the electroplated diamond grinding rod is 20,000 r / min, and the machining dimensional accuracy is ±0.05 mm;

[0051] S3. Fit the inner surface of the blank to the profiling fixture of the inner cavity and fix it by vacuum adsorption. Before opening the vacuum, use an "L"-shaped positioning block to roughly position the blank, and then use a CNC machine tool to precisely position the material using a contact probe. After positioning, use the CNC machine tool to grind the shape of the blank according to the preset CNC rough machining program of the shape. The tool for the CNC rough machining of the shape is an electroplated diamond grinding rod, the mesh number of the electroplated diamond grinding rod is 150 mesh, the diameter of the electroplated diamond grinding rod is 11 mm, and the program for the CNC rough machining of the shape is as follows: the machining removal is 0.25 mm, the spacing of the tools for the CNC rough machining of the shape is 0.18 mm, the rotation speed of the electroplated diamond grinding rod is 20,000 r / min, and the machining dimensional accuracy is ±0.05 mm;

[0052] S4. Fit the inner surface of the blank to the profiling fixture of the inner cavity and fix it by vacuum adsorption. Use a polishing machine to rough-polish the outer surface of the blank. Then, limit and fix the four sides of the blank. Use a polishing machine to rough-polish the inner surface of the blank. The material of the rough-polishing polishing disk is silicon carbide. The rough-polishing time is 1500s. Then, anneal the blank at a temperature of 1200°C and a time of 20h.

[0053] S5. Fit the outer surface of the blank to the profiling fixture of the outer shape and fix it by vacuum adsorption. Before opening the vacuum, use the "L" type positioning block to fine-tune and roughly position the blank, and then use the CNC machine to use the contact probe to fine-position the material. After positioning, use the CNC machine to grind the inner cavity shape of the blank according to the preset CNC finishing program; fit the inner surface of the blank to the profiling fixture of the inner cavity and fix it by vacuum adsorption. Before opening the vacuum, use the "L" type positioning block to fine-tune and roughly position the blank, and then use the CNC machine to use the contact probe to fine-position the material. The material is precisely positioned. After positioning is completed, the CNC machine tool is used to grind the outer shape of the blank according to a preset CNC finishing program; the CNC finishing tool is an electroplated diamond grinding rod, the mesh size of the electroplated diamond grinding rod is 300 mesh, the diameter of the electroplated diamond grinding rod is 11 mm, the CNC finishing program is as follows: the machining removal is 0.2 mm, the spacing of the CNC rough machining tools of the inner cavity is 0.05 mm, the rotation speed of the electroplated diamond grinding rod is 20,000 r / min, and the machining dimensional accuracy is ±0.05 mm;

[0054] S6. Use a polishing machine to perform medium polishing on the outer surface of the blank, the material of the medium polishing polishing disk is pig hair, and the polishing time of the medium polishing is 1500s. Then use a polishing machine to perform fine polishing on the outer surface of the blank, the material of the fine polishing polishing disk is white grinding leather, and the polishing time of the fine polishing is 1500s. Then use a laser to perform laser engraving on the outer surface of the special-shaped ceramic cover plate, and the laser power of the laser engraving is 20~50W. Finally, perform silk screen printing and AF coating to obtain the zirconia ceramic cover plate.

[0055] Example 2

[0056] An embodiment of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this embodiment and that of Example 1 is that: in step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.1 mm, and the spacing of the tools for the CNC rough machining of the inner cavity is 0.2 mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0057] Example 3

[0058] An embodiment of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this embodiment and that of Example 1 is that: in step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.2 mm, and the spacing of the tools for the CNC rough machining of the inner cavity is 1 mm. The other process parameters and the preparation methods of other steps are the same as the preparation method of the special-shaped ceramic cover plate of Example 1.

[0059] Example 4

[0060] An embodiment of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this embodiment and that of Example 1 is that: in step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.15mm, and the spacing of the tools for the CNC rough machining of the outer shape is 0.1mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0061] Example 5

[0062] An embodiment of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this embodiment and that of Example 1 is that: in step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.3mm, and the spacing of the tools for the CNC rough machining of the outer shape is 0.25mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0063] Comparative Example 1

[0064] A comparative example of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this comparative example and that of Example 1 is that: in step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.3 mm, and the spacing of the tools for the CNC rough machining of the inner cavity is 1.2 mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0065] Comparative Example 2

[0066] A comparative example of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate in this comparative example and that in Example 1 is that: in step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.05 mm, and the spacing of the tools for the CNC rough machining of the inner cavity is 0.1 mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate in Example 1.

[0067] Comparative Example 3

[0068] A comparative example of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this comparative example and that of Example 1 is that: in step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.35 mm, and the spacing of the tools for the CNC rough machining of the outer shape is 0.3 mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0069] Comparative Example 4

[0070] A comparative example of the special-shaped ceramic cover plate of the present invention, the difference between the preparation method of the special-shaped ceramic cover plate described in this comparative example and that of Example 1 is that: in step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.1 mm, and the spacing of the tools for the CNC rough machining of the outer shape is 0.08 mm. The other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0071] Comparative Example 5

[0072] A comparative example of the special-shaped ceramic cover plate of the present invention. The difference between the preparation method of the special-shaped ceramic cover plate described in this comparative example and that of Example 1 is only that: in step S4, the material of the rough polishing polishing disk is wool, and the other process parameters and the preparation methods of other steps are the same as those of the preparation method of the special-shaped ceramic cover plate of Example 1.

[0073] Effect Example 1

[0074] In order to explore the strength performance of the special-shaped ceramic cover plate of the present invention, the special-shaped ceramic cover plates of Examples 1 to 5 and Comparative Examples 1 to 5 were subjected to a drop ball test, an extrusion test, and a four-bar bending test. The specific test methods are as follows:

[0075] (1) Drop ball test: The steel ball has a diameter of φ20 mm and a weight of 32±1 g. The impact strength starts from 0.05 J and increases to 0.07 J, 0.13 J, 0.15 J, and 0.20 J in sequence. The energy of the fracture is recorded. The large surface drop ball is required to withstand an energy greater than 0.07 J, and the four corner drop balls are required to withstand an energy greater than 0.05 J.

[0076] (2) Extrusion test: Place the sample face up on the fixture. The hollowed-out area of ​​the fixture is designed to be 0.3-0.4mm inward on one side of the sample shape. The suspended height inside the fixture is greater than 10mm. The test fixture is made of bakelite furniture (3D shaped samples do not require a fixture). Use a pressure of 10Kgf and a spherical indenter with a radius of R = 10mm (the indenter is made of stainless steel) to squeeze the product. The extrusion pressure increases from 0Kgf to 10Kgf. If it does not reach 10Kgf, record the rupture pressure and it is considered to be a failure.

[0077] (3) Four-bar bending test: The span of the upper bar is 40 mm, the span of the lower bar is 20 mm, the test speed is 10 mm / min, and the battery cover is pressed down until it breaks. The maximum force at the time of rupture is recorded and must meet the requirement of >400 N.

[0078] The test results are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] As can be seen from Table 1, the special-shaped ceramic cover plates obtained by the process methods described in Examples 1 to 5 of the present invention have a low cracking rate, moderate processing time, and a low proportion of poor external light. However, due to the preparation process parameters or the use of polishing discs of other materials for rough polishing in Comparative Examples 1 to 5, the special-shaped ceramic cover plates obtained may have a high cracking rate, extremely long processing time, or a high proportion of poor appearance.

[0083] Effect Example 2

[0084] In order to further explore the processing performance of the special-shaped ceramic cover plate of the present invention, the processing size measurement and surface profile measurement of the special-shaped ceramic cover plates of Examples 1 to 5 and Comparative Examples 1 to 5 were performed. The specific test methods are as follows:

[0085] (1) Processing dimension measurement: CCD projection measurement, the test standard is shown in the test tolerance in Table 2 below;

[0086] (2) Surface profile measurement: CAV scanning measurement, the scanning profile standard must be less than 0.2.

[0087] The test results are shown in Table 2.

[0088] Table 2

[0089]

[0090]

[0091] As can be seen from Table 2, the special-shaped ceramic cover plates of Examples 1-5, Comparative Example 2, and Comparative Examples 4-5 of the present invention meet the processing performance requirements. However, the special-shaped ceramic cover plates of Comparative Examples 1 and 3 have an opening size tolerance or an inner height tolerance that exceeds the performance requirements of the standard test tolerance.

[0092] Effect Example 3

[0093] In order to further explore the appearance performance of the special-shaped ceramic cover plate of the present invention, the appearance inspection was carried out on the special-shaped ceramic cover plates of Examples 1 to 5 and Comparative Examples 1 to 5. The specific test method was: mesh inspection, reference limit sample, the test quantity was 100 pieces, and the qualified rate and defective ratio of the 100 samples were counted.

[0094] The test results are shown in Table 3.

[0095] Table 3

[0096]

[0097]

[0098] As can be seen from Table 3, the appearance qualification rate of the special-shaped ceramic cover plates obtained by the preparation method of Examples 1 to 5 using the present invention is 74% to 79%, and the defective proportions of surface sand, grading, and knife marks are low. However, by changing the process parameters of CNC rough processing in the preparation method or using polishing discs of other materials for rough polishing, the appearance qualification rate of Examples 1 to 5 is only 59% to 71%.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a special-shaped ceramic cover plate, characterized in that: The following steps are involved: S1. Roughly trimming the shape of the blank of the special-shaped ceramic cover plate; S2. Fitting and fixing the outer surface of the blank to the profiling fixture of the outer shape, and performing CNC rough machining of the inner cavity on the inner surface of the blank; the machining removal amount of the CNC rough machining of the inner cavity is 0.1-0.2 mm, and the spacing between the tools of the CNC rough machining of the inner cavity is 0.2-1 mm; S3. Fitting the inner surface of the blank to the profiling fixture of the inner cavity, and performing CNC rough machining of the outer surface of the blank; the machining removal amount of the CNC rough machining of the outer shape is 0.15-0.3 mm, and the spacing between the tools of the CNC rough machining of the outer shape is 0.1-0.25 mm; S4, rough polishing the inner and outer surfaces of the blank and annealing; the material of the rough polishing polishing disk is silicon carbide; S5, performing CNC finishing on the inner and outer surfaces of the blank respectively; S6. Performing intermediate polishing and fine polishing on the outer surface of the blank in sequence to obtain the special-shaped ceramic cover plate.

2. The method for preparing a special-shaped ceramic cover plate according to claim 1, wherein: In the step S2, the machining removal amount of the CNC rough machining of the inner cavity is 0.15 mm, and the spacing between the tools of the CNC rough machining of the inner cavity is 0.8 mm.

3. The method for preparing a special-shaped ceramic cover plate according to claim 1, wherein: In the step S3, the machining removal amount of the CNC rough machining of the outer shape is 0.25 mm, and the spacing between the tools of the CNC rough machining of the outer shape is 0.18 mm.

4. The method for preparing a special-shaped ceramic cover plate according to any one of claims 1 to 3, characterized in that: In step S4, the rough polishing time is 1000 to 2000 seconds.

5. The method for preparing a special-shaped ceramic cover plate according to claim 1, wherein: In step S5, the machining removal amount of the CNC finishing is 0.15-0.3 mm, and the spacing between the tools of the CNC finishing is 0.01-0.1 mm.

6. The method for preparing a special-shaped ceramic cover plate according to claim 1, wherein: The method further includes step S7, wherein the outer surface of the special-shaped ceramic cover plate is sequentially laser engraved, silk-screened and coated.

7. A special-shaped ceramic cover plate obtained by the preparation method of the special-shaped ceramic cover plate according to any one of claims 1 to 6.

8. Use of the special-shaped ceramic cover plate according to claim 7 in preparing special-shaped back covers of electronic products.

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