A grinding medium for removing ceramic ball / bead processing surface parting lines and gates and its method of manufacture and use

Abstract

The application discloses a kind of grinding medium for removing ceramic ball / pearl processing surface die line and gate and its preparation method and application, the grinding medium for removing ceramic ball / pearl processing surface die line and gate provided by the application is ceramic sleeve formed by pressing and sintering of yttrium stabilized zirconia powder.Use polishing machine and the special grinding medium described above can effectively and efficiently remove the gate and die line on the surface of ceramic ball / pearl, and the quality and roughness of the surface of the product produced meet the requirements.Using the scheme provided by the application can improve product stability, improve product capacity and reduce production cost.

Description

Technical Field

[0001] This invention relates to the field of abrasive media preparation technology, specifically to an abrasive media for removing parting lines and gates from the surface of ceramic balls / beads, its preparation method, and its application. Background Technology

[0002] Ceramics are multiphase solid materials composed of inorganic compounds, made by shaping and high-temperature sintering encapsulated compounds, whether natural or synthetic. Precision ceramics can be used to manufacture circuit substrates, coil frames, electron tube sockets, high-voltage insulating porcelain, and rocket nose cones, among other things. However, because ceramics are prone to shrinkage during sintering, the sintered product often differs from the unsintered blank. The most common issue is the presence of obvious parting lines and gates on the surface of the sintered ceramic spheres / beads, which significantly limits their application as high-precision ceramic materials. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of the prior art by providing an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads, as well as its preparation method and application.

[0004] The technical problem solved by this invention is achieved by the following technical solution.

[0005] This invention provides an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads. The abrasive medium is a ceramic sleeve formed by pressing and sintering yttrium-stabilized zirconia powder.

[0006] The present invention also provides a method for preparing the above-mentioned grinding media, which includes: extruding yttrium-stabilized zirconium oxide powder into a tubular blank, and then sintering the tubular blank to obtain the grinding media.

[0007] The present invention also provides a method for treating the parting line and gate on the surface of ceramic balls / beads, which includes: pre-firing pre-fired material obtained by injection or pressing of ceramic balls / beads and mixing it with grinding media, and then polishing the ceramic balls / beads.

[0008] The present invention has the following beneficial effects:

[0009] This invention provides an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads, its preparation method, and its application. The abrasive medium provided by this invention is a ceramic sleeve formed by pressing and sintering yttrium-stabilized zirconia powder. Using this abrasive medium can effectively remove parting lines and gates from the surface of ceramic balls / beads, improving the efficiency and quality of polishing, shortening polishing time, and reducing production costs. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 The grinding media are prepared using the methods provided in Examples 1-3 of this invention;

[0012] Figure 2 An appearance drawing of the product prepared using the method provided in Example 4 of this invention;

[0013] Figure 3 An appearance drawing of the product prepared using the method provided in Example 5 of this invention;

[0014] Figure 4 An appearance drawing of the product prepared using the method provided in Comparative Example 2 of this invention;

[0015] Figure 5 The image shows the appearance of the product prepared using the method provided in Comparative Example 3 of this invention.

[0016] Figure 6 An appearance drawing of the product prepared using the method provided in Comparative Example 4 of this invention;

[0017] Figure 7 To remove the parting line and gate on the surface of ceramic balls / beads using the method provided in Comparative Example 5 of this invention, the left figure shows an alumina tube abrasive media with a diameter of 10mm*5mm*20mm, and the right figure shows the appearance of a product treated with abrasive media of this size.

[0018] Figure 8 To remove the parting line and gate on the surface of ceramic balls / beads using the method provided in Comparative Example 6 of this invention, the left figure shows a Φ7mm brown corundum ball abrasive media, and the right figure shows the appearance of the product treated with this specification of abrasive media.

[0019] Figure 9 To remove the parting line and gate on the surface of ceramic balls / beads using the method provided in Comparative Example 7 of this invention, the left figure shows a Φ2mm brown corundum ball abrasive media, and the right figure shows the appearance of the product treated with this specification of abrasive media. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0021] The following is a detailed description of an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads, its preparation method, and its application, provided by an embodiment of the present invention.

[0022] In a first aspect, embodiments of the present invention provide an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads. The abrasive medium is a ceramic sleeve formed by pressing and sintering yttrium-stabilized zirconia powder.

[0023] This invention provides an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads. Its suitable weight and sleeve-shaped design allow it to effectively remove gates and parting lines through collision and friction during operation after mixing with the ceramic balls / beads, minimizing damage to the product's appearance. This enables faster polishing after final firing and improves surface roughness. Using this abrasive medium, parting lines and gates can be effectively removed from the surface of ceramic balls / beads without affecting product surface quality. Other types of abrasive media, however, can cause significant scratches to the product surface, making subsequent polishing processes ineffective.

[0024] In some alternative embodiments, the abrasive media have dimensions of Φ2.15mm * Φ1.24mm * 8.5mm and a density of 6.0-6.05g / cm³. 3 Its Vickers hardness is 950-1300 MPa, and its three-point bending strength is 900-1200 MPa.

[0025] Secondly, embodiments of the present invention also provide a method for preparing the above-mentioned grinding media, which includes: extruding yttrium-stabilized zirconium oxide powder into a tubular blank, and then sintering the tubular blank to prepare the grinding media.

[0026] In some alternative embodiments, the tubular preform is formed by placing yttrium-stabilized zirconia powder in a rubber mold and pressing it under isostatic pressure at 170-200 MPa.

[0027] In some alternative embodiments, the tubular blank is first heated from room temperature to 1400-1500°C and held for 2-3 hours, then cooled to 800-900°C and held for 2-3 hours, and then naturally cooled to room temperature to obtain the grinding media. Preferably, the high-temperature sintering process takes 36-40 hours.

[0028] In some optional embodiments, the yttrium oxide content in the yttrium-stabilized zirconia powder is 2 mol% to 4 mol%.

[0029] Thirdly, embodiments of the present invention also provide a method for treating the parting line and gate on the surface of ceramic balls / beads, which includes: pre-firing pre-fired material obtained by injection or pressing of ceramic balls / beads and mixing it with grinding media, and then polishing the ceramic balls / beads.

[0030] The method for treating parting lines and gates on the surface of ceramic balls / beads provided in this invention includes: pre-firing the injection-molded or pressed ceramic balls / beads; mixing the pre-fired material with abrasive media; and polishing the ceramic balls / beads. Pre-firing the injection-molded or pressed ceramic balls / beads increases their hardness, preventing breakage during polishing. After pre-firing, the ceramic balls / beads are mixed with abrasive media for polishing, effectively removing parting lines and gates from their surface.

[0031] In some optional embodiments, the following steps are included: pre-firing the ceramic balls / beads formed by injection or compression to obtain pre-fired material, mixing it with grinding media, placing it in a polishing machine to perform a first polishing treatment on the ceramic balls / beads, then screening out the ceramic balls / beads after the first polishing, and performing a second sintering and polishing to obtain high-precision ceramic balls / beads with smooth surfaces.

[0032] The method for treating parting lines and gates on the surface of ceramic balls / beads provided in this invention involves first pre-firing the injection-molded or pressed ceramic balls / beads. Pre-firing increases the hardness of the ceramic balls / beads, preventing breakage during polishing. The pre-firing also ensures that the hardness is not excessive, facilitating the effective removal of parting lines and gates. Then, the pre-fired material is mixed with abrasive media for a first polishing process, removing most of the parting lines and gates from the surface of the ceramic balls / beads. After the first polishing, the ceramic balls / beads are sieved and subjected to a second sintering and polishing process. This effectively removes any remaining parting lines and gates from the surface of the ceramic balls / beads after the first polishing, achieving a fine polishing effect while simultaneously increasing the hardness of the ceramic balls / beads, ultimately resulting in smooth, high-precision ceramic balls / beads. Multiple treatments have shown that the above-described method for treating parting lines and gates on the surface of ceramic balls / beads can effectively remove these features, significantly improving product stability, further increasing production capacity, and reducing production costs.

[0033] In some alternative embodiments, the pre-firing temperature of the ceramic balls / beads is 900-1050°C.

[0034] If the pre-firing temperature of the ceramic balls / beads made by injection or compression is too low, the strength of the ceramic balls / beads after pre-firing will be insufficient, which will cause the product to break during the polishing process. If the pre-firing temperature is too high, the hardness of the product will increase, which will prolong the polishing process.

[0035] In some alternative embodiments, the mass ratio of pre-fired material to abrasive media is 1:2-2.5, and the polishing time for one polishing cycle is 7-8 hours. If the mixing ratio of pre-fired material to abrasive media is too low, it will not be able to effectively remove parting lines and gates from the surface of ceramic balls / beads. On the other hand, if the mixing ratio is too high, the product loading will be small, which will reduce the polishing efficiency.

[0036] In some alternative embodiments, the secondary sintering temperature of the ceramic balls / beads is 1400-1480℃. After the secondary sintering is completed, the temperature is lowered to room temperature, and the polishing time is 14-18 hours.

[0037] The present invention will be further described below with reference to embodiments.

[0038] Example 1

[0039] A method for preparing abrasive media for removing parting lines and gates from the surface of ceramic balls / beads includes the following steps:

[0040] a. The raw material is yttrium-stabilized zirconia powder, in which the yttrium oxide content is 3 mol%.

[0041] b. Design and manufacture the rubber mold according to the dimensions of the grinding media.

[0042] c. Fill the raw materials into the rubber mold, and place the filled rubber mold into an isostatic press and press it into a tubular preform using a pressure of 170MPa.

[0043] d. After pressing, the tubular blank is demolded and placed in the kiln. The temperature inside the kiln is raised from room temperature to 1450℃, and then kept at 1450℃ for 2 hours. After that, the temperature is lowered to 900℃ within 3 hours, and then the temperature is naturally lowered from 900℃ to room temperature.

[0044] See product appearance. Figure 1 As can be seen, the grinding media is a milky white sleeve. The relevant performance tests of the prepared grinding media are as follows: the dimensions of the grinding media are Φ2.15mm*Φ1.24mm*8.5mm, and the density is 6.02g / cm³. 3 Its Vickers hardness is 1300 MPa, and its three-point bending strength is 1000 MPa.

[0045] Example 2

[0046] A method for preparing abrasive media for removing parting lines and gates from the surface of ceramic balls / beads includes the following steps:

[0047] a. The raw material is yttrium-stabilized zirconia powder, in which the yttrium oxide content is 3 mol%.

[0048] b. Design and manufacture the rubber mold according to the dimensions of the grinding media.

[0049] c. Fill the raw materials into the rubber mold, and then place the filled rubber mold into an isostatic press and press it into a tubular preform using a pressure of 180MPa.

[0050] d. After pressing, the tubular blank is demolded and placed in the kiln. The temperature inside the kiln is raised from room temperature to 1400℃, and then kept at 1400℃ for 2 hours. After that, the temperature is lowered to 800℃ within 3 hours, and then the temperature is naturally lowered from 800℃ to room temperature.

[0051] See product appearance. Figure 1 As can be seen, the grinding media is a milky white sleeve. The relevant performance tests of the prepared grinding media are as follows: the dimensions of the grinding media are Φ2.15mm*Φ1.24mm*8.5mm, and the density is 6.0g / cm³. 3 Its Vickers hardness is 1000 MPa and its 3-point bending strength is 1100 MPa.

[0052] Example 3

[0053] A method for preparing abrasive media for removing parting lines and gates from the surface of ceramic balls / beads includes the following steps:

[0054] a. The raw material is yttrium-stabilized zirconia powder, in which the yttrium oxide content is 3 mol%.

[0055] b. Design and manufacture the rubber mold according to the dimensions of the grinding media.

[0056] c. Fill the raw materials into the rubber mold, and place the filled rubber mold into an isostatic press and press it into a tubular preform using a pressure of 200MPa.

[0057] d. After pressing, the tubular blank is demolded and placed in the kiln. The temperature inside the kiln is raised from room temperature to 1500℃, and then kept at 1500℃ for 2 hours. After that, the temperature is lowered to 900℃ within 4 hours, and then the temperature is naturally lowered from 900℃ to room temperature.

[0058] See product appearance. Figure 1As can be seen, the grinding media is a milky white sleeve. The relevant performance tests of the prepared grinding media are as follows: the dimensions of the grinding media are Φ2.15mm*Φ1.24mm*8.5mm, and the density is 6.04g / cm³. 3 Its Vickers hardness is 1280 MPa, and its three-point bending strength is 1000 MPa.

[0059] Example 4

[0060] The method for treating the parting line and gate on the surface of ceramic balls / beads includes the following steps:

[0061] a. Pre-sintering the pressed or injected ceramic balls / beads at 900℃ using a dedicated kiln to obtain pre-fired material.

[0062] b. Mix the above-mentioned pre-fired material with the Φ2.15mm*Φ1.24mm*8.5mm ceramic tube prepared in Example 1 at a mass ratio of 1:2.

[0063] c. Place the mixed materials into the polishing machine and turn on the polishing machine for a polishing process of 7 hours.

[0064] d. Turn off the polishing machine, screen and separate the ceramic balls / beads after the first polishing, and then sinter the ceramic balls / beads after the first polishing at 1450℃ for 16 hours to obtain high-precision ceramic balls / beads with smooth surfaces.

[0065] See product appearance. Figure 2 As can be seen, the polished ceramic balls / beads have smooth surfaces, no parting lines or gates, and are therefore considered qualified products.

[0066] Example 5

[0067] The method for treating the parting line and gate on the surface of ceramic balls / beads includes the following steps:

[0068] a. Pre-sintering the pressed or injected ceramic balls / beads at 1050℃ using a dedicated kiln to obtain pre-fired material.

[0069] b. Mix the above-mentioned pre-fired material with the Φ2.15mm*Φ1.24mm*8.5mm ceramic tube prepared in Example 1 at a mass ratio of 1:2.5.

[0070] c. Place the mixed materials into the polishing machine and turn on the polishing machine for a polishing process of 7 hours.

[0071] d. Turn off the polishing machine, screen and separate the ceramic balls / beads after the first polishing, and then sinter the ceramic balls / beads after the first polishing at 1480℃ for 16 hours to obtain high-precision ceramic balls / beads with smooth surfaces.

[0072] See product appearance. Figure 3 As can be seen, the polished ceramic balls / beads have smooth surfaces, no parting lines or gates, and are therefore considered qualified products.

[0073] Comparative Example 1

[0074] Ceramic balls / beads manufactured by pressing or injection molding were polished using a tumbler polisher. After 70 hours of polishing, it was observed that the gate portion on the surface of the ceramic balls / beads was still not removed. After another 60 hours of polishing, it was still observed that slight small gates were still present. This method has low polishing efficiency, causes significant wear and tear on the equipment, and also consumes a great deal of abrasive media.

[0075] Comparative Example 2

[0076] The steps are the same as in Example 2, except that the ceramic balls / beads formed by pressing or injection are not pre-fired. They are directly polished for 130 hours.

[0077] See product appearance. Figure 4 As can be seen, the parting line on the surface of the polished ceramic balls / beads has been removed, but the gate has not been completely removed. Therefore, this product is deemed defective.

[0078] Comparative Example 3

[0079] The steps are the same as in Example 2, except that the pre-firing temperature of the ceramic balls / beads formed by pressing or injection is <900°C.

[0080] See product appearance. Figure 5 As can be seen, the polished ceramic balls / beads have smooth, broken surfaces, and are therefore deemed unqualified products.

[0081] Comparative Example 4

[0082] The steps are the same as in Example 2, except that the pre-firing temperature of the ceramic balls / beads formed by pressing or injection is >1050°C.

[0083] See product appearance. Figure 6 It can be seen that the parting line and gate on the surface of the polished ceramic ball / bead were not removed, and the polishing effect was not achieved, so it was judged as a defective product.

[0084] Comparative Example 5

[0085] A method for treating the parting line and gate on the surface of ceramic spheres / beads includes the following steps:

[0086] a. Grinding media consisting of pressed or injection-molded ceramic balls / beads and Φ10mm*Φ5mm*20mm alumina tubes (see...) Figure 6 (The left image in the image) is mixed at a mass ratio of 1:2.

[0087] b. Place the mixed materials into the polishing machine and turn on the polishing machine for 7 hours.

[0088] c. Turn off the polishing machine and separate the polished ceramic balls / beads from the grinding media to obtain polished ceramic balls / beads.

[0089] See product appearance. Figure 7 The right image shows that the ceramic balls / beads were damaged on the surface after processing due to excessive weight of the grinding media, but were still deemed to be qualified products.

[0090] Comparative Example 6

[0091] The method for treating the parting line and gate on the surface of ceramic balls / beads includes the following steps:

[0092] a. Grind pressed or injected ceramic balls / beads with Φ7mm brown fused alumina balls as grinding media (see...). Figure 7 (The left image in the image) is mixed at a mass ratio of 1:2.

[0093] b. Place the mixed materials into the polishing machine and turn on the polishing machine for 7 hours.

[0094] c. Turn off the polishing machine and separate the polished ceramic balls / beads from the grinding media to obtain polished ceramic balls / beads.

[0095] See product appearance. Figure 8 As shown in the right image, this type of grinding media cannot effectively remove the parting line and gate on the surface of ceramic balls / beads, and is therefore deemed a substandard product.

[0096] Comparative Example 7

[0097] The method for treating the parting line and gate on the surface of ceramic balls / beads includes the following steps:

[0098] a. Grind pressed or injected ceramic balls / beads with Φ2mm brown fused alumina balls as grinding media (see...). Figure 8 (The left image in the image) is mixed at a mass ratio of 1:2.

[0099] b. Place the mixed materials into the polishing machine and turn on the polishing machine for 7 hours.

[0100] c. Turn off the polishing machine and separate the polished ceramic balls / beads from the grinding media to obtain polished ceramic balls / beads.

[0101] See product appearance. Figure 9 As shown in the right image, this type of grinding media cannot effectively remove the parting line and gate on the surface of ceramic balls / beads, and is therefore deemed a substandard product.

[0102] As can be seen from the above: In Comparative Example 1, using a tumbler polisher to polish ceramic balls / beads is not only inefficient, but also produces substandard samples. In Comparative Examples 2-4, the lack of pre-firing or an unsuitable pre-firing temperature for pressed or injection-molded ceramic balls / beads will prevent the effective removal of parting lines and gates from their surfaces. In Comparative Example 5, the tubular abrasive media, due to its excessive weight, will damage the surface of the ceramic balls / beads, and subsequent processing will not completely remove the parting lines and gates. In Comparative Examples 6-7, the use of spherical abrasive media for removing parting lines and gates from the ceramic balls / beads is inefficient and cannot completely remove them.

[0103] In summary, this invention provides an abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads, its preparation method, and its application. A ceramic sleeve with dimensions of Φ2.15mm*Φ1.24mm*8.5mm, prepared according to this invention, is used as the dedicated abrasive medium to remove parting lines and gates from the surface of ceramic balls / beads. The final product testing results show that all parting lines and gates on the surface of the ceramic balls / beads are removed, and the surface quality and roughness meet the requirements. Practice shows that using the solution provided by this invention, the efficiency of removing parting lines and gates from the surface of ceramic balls / beads is increased by more than 200%, the production cycle is greatly shortened, and the cost is reduced by 50%. Based on the significant improvement in both production efficiency and quality, the prepared high-precision ceramic balls / beads with smooth surfaces can meet the needs of high-end customers.

[0104] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An abrasive medium for removing parting lines and gates from the surface of ceramic balls / beads, characterized in that, The grinding media is a ceramic sleeve made by pressing and sintering yttrium-stabilized zirconium oxide powder.

2. The grinding media according to claim 1, characterized in that, The grinding media has dimensions of Φ2.15mm*Φ1.24mm*8.5mm and a density of 6.0-6.05g / cm³. 3 Its Vickers hardness is 950-1300 MPa, and its three-point bending strength is 900-1200 MPa.

3. A method for preparing the grinding media according to claim 1 or 2, characterized in that, It includes: Yttrium-stabilized zirconia powder is extruded into a tubular blank, and then the tubular blank is sintered at high temperature to prepare the grinding media.

4. The preparation method according to claim 3, characterized in that, The tubular preform is formed by placing the yttrium-stabilized zirconia powder in a rubber mold and pressing it under isostatic pressure at 170-200 MPa.

5. The preparation method according to claim 3, characterized in that, The high-temperature sintering of the tubular blank includes: first heating the tubular blank from room temperature to 1400-1500℃ and holding it at that temperature for 2-3 hours, then cooling it to 800-900℃ within 2-4 hours, and then naturally cooling it back to room temperature to obtain the grinding media. Preferably, the entire high-temperature sintering process takes 36-40 hours.

6. A method for treating the parting line and gate on the surface of ceramic balls / beads, characterized in that, It includes: The pre-fired material obtained by pre-firing ceramic balls / beads formed by injection or compression is mixed with grinding media, and then the ceramic balls / beads are polished.

7. The processing method according to claim 6, characterized in that, Includes the following steps: The pre-fired ceramic balls / beads, which are produced by injection or compression, are mixed with grinding media and then placed in a polishing machine to perform a first polishing process. The polished ceramic balls / beads are then screened out and subjected to a second sintering and polishing to obtain high-precision ceramic balls / beads with smooth surfaces.

8. The processing method according to claim 7, characterized in that, The pre-firing temperature of the ceramic balls / beads formed by injection or pressing is 900-1050℃.

9. The processing method according to claim 7, characterized in that, The mass ratio of pre-burned material to grinding media is 1:2-2.5, and the polishing time is 7-8 hours per polishing process.

10. The processing method according to claim 7, characterized in that, The secondary sintering temperature of the ceramic balls / beads is 1400-1480℃. After the secondary sintering is completed, the temperature is lowered to room temperature, and the polishing time is 14-18 hours.

Images