Manufacturing method for ceramic member

Abstract

To provide a manufacturing method for a ceramic member, which can make both a quality of a polished surface of the ceramic member and polishing efficiency compatible, in a step of polishing the ceramic member.SOLUTION: A manufacturing method for a ceramic member comprises a preparing step of preparing a ceramic member, dispersed liquid in which abrasive grain mechanochemically reacting with the ceramic member is dispersed in liquid, and a surface plate; and a polishing step of polishing the ceramic member while pressing the ceramic member against the surface plate, in a state where the dispersed liquid is supplied to a space between the ceramic member and the surface plate, where a ratio of weight of the abrasive grain to the liquid is higher than 0% and 40% or lower.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a ceramic component. [Background technology]

[0002] BACKGROUND ART Conventionally, there has been known a method for manufacturing a ceramic member that includes a polishing step of polishing the ceramic member by utilizing a mechanochemical reaction between the ceramic member and abrasive grains (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-117806 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even with prior art such as that disclosed in Patent Document 1, there is still room for improvement in the technology for achieving both the quality of the polished surface of the ceramic member and polishing efficiency in the polishing step of the ceramic member in the manufacturing method of the ceramic member.

[0005] An object of the present invention is to provide a technique for achieving both high quality of the polished surface of a ceramic member and high polishing efficiency in the polishing step of the ceramic member in a method for manufacturing a ceramic member. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0007] (1) According to one aspect of the present invention, there is provided a method for manufacturing a ceramic member, the method comprising: a preparation step of preparing a ceramic member, a dispersion liquid in which abrasive grains that mechanochemically react with the ceramic member are dispersed, and a surface plate; and a polishing step of polishing the ceramic member while pressing the ceramic member against the surface plate while the dispersion liquid is supplied between the ceramic member and the surface plate, wherein the weight ratio of the abrasive grains to the liquid in the dispersion liquid is greater than 0% and not more than 40%.

[0008] According to this configuration, the weight ratio of abrasive grains to the liquid in the dispersion liquid supplied between the ceramic member and the surface plate during the polishing process is greater than 0% and less than 40%. During the polishing process, the ceramic member is polished while the dispersion liquid is supplied between the ceramic member and the surface plate and the ceramic member is pressed against the surface plate. Here, "a state in which the dispersion liquid is being supplied" includes not only a state in which the dispersion liquid is continuously supplied, but also a state in which the dispersion liquid remains between the ceramic member and the surface plate even after the supply of the dispersion liquid has stopped. This prevents a shortage of abrasive grains between the ceramic member and the surface plate, thereby ensuring the mechanochemical reaction between the ceramic member and the abrasive grains. Therefore, the polishing time can be shortened while maintaining the quality of the polished surface of the ceramic member, thereby achieving both high polishing surface quality and high polishing efficiency.

[0009] (2) In the method for manufacturing a ceramic member according to the above aspect, in the polishing step, the dispersion may be supplied between the ceramic member and the platen so that the ceramic member is immersed in the dispersion. According to this configuration, in the polishing step, the ceramic member is immersed in the dispersion, which can suppress abrasive grain breakage on the polishing surface of the ceramic member. Here, "immersing" includes a state in which a portion of the ceramic member is immersed in the dispersion. This ensures that the mechanochemical reaction between the ceramic member and the abrasive grains proceeds, thereby further improving the polishing efficiency while maintaining the quality of the polished surface.

[0010] (3) In the method for manufacturing a ceramic member according to the above aspect, the preparation step may include preparing the ceramic member made of silicon nitride and the dispersion containing the abrasive grains made of iron oxide. According to this configuration, the preparation step includes preparing the ceramic member made of silicon nitride and the dispersion containing the abrasive grains made of iron oxide. This makes it possible to achieve both high quality of the polished surface of the ceramic member made of silicon nitride and high polishing efficiency.

[0011] (4) In the method for manufacturing a ceramic member according to the above aspect, the preparation step may include preparing the platen having iron oxide on its surface. According to this configuration, when polishing a ceramic member made of silicon nitride in the polishing step, abrasive grains supplied with the dispersion liquid are more likely to be held by the iron oxide on the surface of the platen. Furthermore, if there is a shortage of abrasive grains, a mechanochemical reaction between the iron oxide on the platen and the silicon nitride of the ceramic member proceeds. This further prevents the loss of iron oxide during polishing of a ceramic member made of silicon nitride. Therefore, deterioration in the quality of the polished surface can be suppressed.

[0012] (5) In the method for manufacturing a ceramic member according to the above aspect, the preparation step may include preparing the surface plate that has not been hardened. According to this configuration, a surface plate that has not been hardened is more likely to retain the dispersion liquid on its surface. This helps to prevent abrasive grain breakage on the polishing surface of the ceramic member, thereby making it easier to achieve both high quality and high polishing efficiency for the polishing surface of the ceramic member made of silicon nitride.

[0013] (6) In the method for manufacturing a ceramic member according to the above aspect, the preparation step may include preparing the surface plate having a buff provided thereon, and the polishing step may include polishing the ceramic member while pressing the ceramic member against the buff while the dispersion is supplied between the ceramic member and the buff. This configuration makes it easier for the dispersion to be retained by the buff provided on the surface plate. This makes it easier to prevent abrasive grain breakage on the polished surface of the ceramic member, thereby making it easier to achieve both high quality and polishing efficiency for the polished surface of a ceramic member made of silicon nitride.

[0014] (7) In the method for manufacturing a ceramic member according to the above aspect, the polishing step may include rotating at least one of the ceramic member and the surface plate to polish the ceramic member. According to this configuration, the polishing step rotates at least one of the ceramic member and the surface plate, thereby improving polishing efficiency.

[0015] (8) In the method for manufacturing a ceramic member according to the above aspect, the preparation step may include preparing the spherical ceramic member and a pair of surface plates having recessed surfaces, and the polishing step may include moving the pair of surface plates at different speeds while sandwiching the ceramic member between their respective surfaces to polish the ceramic member. According to this configuration, the pair of surface plates sandwiching the spherical ceramic member move at different speeds, causing the ceramic member to rotate between the pair of surface plates. This allows the surface of the ceramic member to be polished evenly. Furthermore, because the dispersion liquid tends to accumulate in the recessed surfaces of the surface plates, abrasive breakage is easily suppressed, making it easier to achieve both high quality of the polished surface and high polishing efficiency.

[0016] The present invention can be realized in various forms, such as a ceramic member manufactured by a method for manufacturing a ceramic member, a polishing apparatus for a ceramic member used in the method for manufacturing a ceramic member, a method for controlling the polishing apparatus for a ceramic member, a computer program for causing the polishing apparatus for a ceramic member to manufacture a ceramic member, a server device for distributing the computer program, and a non-transitory storage medium on which the computer program is stored. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a polishing apparatus according to a first embodiment. [Figure 2] 2A and 2B are diagrams illustrating the positional relationship between a platen and a holder provided in the polishing apparatus. [Figure 3] FIG. [Figure 4] 10A and 10B are diagrams illustrating a state in which a ceramic member is being polished. [Figure 5] 3 is a flowchart of a method for manufacturing a ceramic member according to the first embodiment. [Figure 6] FIG. 1 is a first diagram illustrating an evaluation test of a manufacturing method for a ceramic member. [Figure 7] FIG. 10 is a second diagram illustrating an evaluation test of the method for manufacturing the ceramic member. [Figure 8] FIG. 10 is a third diagram illustrating an evaluation test of the manufacturing method of the ceramic member. [Figure 9] FIG. 10 is a fourth diagram illustrating an evaluation test of the manufacturing method of the ceramic member. [Figure 10] FIG. 4 is a partial schematic view of a polishing apparatus according to a second embodiment. [Figure 11] FIG. 10 is a schematic view of a polishing apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] First Embodiment FIG. 1 is a schematic diagram of a polishing apparatus used in the method for manufacturing a ceramic member according to the first embodiment. FIG. 2 is a diagram illustrating the positional relationship between a platen and a holder included in the polishing apparatus according to the present embodiment. The polishing apparatus 1 according to the present embodiment is used to mirror-polish the surfaces of ceramic members Pc1 during the manufacturing process of the ceramic members Pc1. The polishing apparatus 1 includes a platen 10, a holder 20, and a dispersion liquid supply unit 30. The polishing apparatus 1 according to the present embodiment can simultaneously polish the surfaces of multiple ceramic members Pc1. The ceramic members Pc1 polished by the polishing apparatus 1 according to the present embodiment are made of silicon nitride. FIGS. 1 and 2 show the z-axis, which is the z-axis direction along the vertical direction, and the x-axis and y-axis, which are the x-axis and y-axis directions along the horizontal direction and perpendicular to each other, in the polishing apparatus 1 installed for polishing the ceramic members Pc1. Note that the polishing apparatus 1 used in the method for manufacturing the ceramic members Pc1 according to the present embodiment is not limited to the polishing apparatus 1 having the configuration shown in FIG. 1. Furthermore, the material forming the ceramic member Pc1 polished by the polishing apparatus 1 is not limited to silicon nitride.

[0019] 2, the surface plate 10 has a substantially circular plate shape. The surface plate 10 is provided on the base portion 1a of the polishing apparatus 1. The surface plate 10 of this embodiment contains iron, has iron oxide on the surface 11, and has not been hardened.

[0020] FIG. 3 is a diagram showing the surface of the surface plate. FIG. 3 shows surface 11 of surface plate 10 of this embodiment, as well as surface 91 of surface plate 90 of a comparative example that has not been hardened. Surface plate 10 of this embodiment contains iron, and iron oxide is formed on surface 11, so as shown in FIG. 3, the surface is darker than that of surface plate 90 of the comparative example. A first drive unit 1b provided on base 1a is connected to the center of surface plate 10 (see FIG. 1). By the rotational torque output by first drive unit 1b, surface plate 10 can rotate in the direction of outline arrow R1 shown in FIG. 2, which shows the positional relationship between surface plate 10 and holder 20 as viewed from above in the vertical direction.

[0021] The holder 20 is provided vertically above the surface 11 of the platen 10 (on the positive side in the z-axis direction). As shown in FIG. 2, the holder 20 has a substantially cylindrical shape and is formed to be able to hold a plurality of ceramic members Pc1 along its circumferential direction. Each of the plurality of ceramic members Pc1 held by the holder 20 is located near the surface 11 of the platen 10 and may even come into contact with the surface 11 of the platen 10. A second drive unit 1d is connected to the center of the holder 20. The second drive unit 1d is disposed on top of the base unit 1a on which the operation unit 1c of the polishing apparatus 1 and the like are provided. The holder 20 can rotate in the direction of the white arrow R2 shown in FIG. 2 by the rotational torque output by the second drive unit 1d.

[0022] In the polishing apparatus 1 of this embodiment, the platen 10 and the holder 20 are each independently rotatable. Specifically, as shown in FIG. 2, the platen 10 rotates in the direction of the white arrow R1 around the first rotation axis C1, while the holder 20 rotates in the direction of the white arrow R2 around the second rotation axis C2 at a position separate from the first rotation axis C1. As shown in FIG. 2, the second rotation axis C2 of the holder 20 moves along the circumference of an imaginary circle VR1 centered on the first rotation axis C1 of the platen 10. In the holder 20, the plurality of ceramic members Pc1 are arranged to surround the second rotation axis C2. As a result, the plurality of ceramic members Pc1 can be efficiently polished by the rotation of the platen 10 and the holder 20.

[0023] The dispersion supply unit 30 supplies a dispersion between the surface 11 of the platen 10 and the ceramic member Pc1 held by the holder 20. The dispersion supply unit 30 includes a storage tank 31 for storing the dispersion and a supply hose 32 for supplying the dispersion stored in the storage tank 31 between the ceramic member Pc1 and the surface 11 of the platen 10. The dispersion stored in the storage tank 31 is a liquid in which abrasive grains that undergo a mechanochemical reaction with the ceramic member Pc1 are dispersed. In the dispersion, the weight ratio of the abrasive grains to the liquid is greater than 0% and not more than 40%. The dispersion of this embodiment contains an alkaline liquid containing water and a small amount of coolant, and abrasive grains made of iron oxide. In the dispersion of this embodiment, the weight ratio of the abrasive grains to the liquid is 20%.

[0024] FIG. 4 is a diagram illustrating the state in which a ceramic member is being polished using the polishing apparatus of this embodiment. FIG. 4 is an enlarged cross-sectional view of a portion of the ceramic member Pc1 located near the surface 11 of the platen 10. When the ceramic member Pc1 is being polished using the polishing apparatus 1, as shown in FIG. 4, the dispersion liquid Ld is present between the ceramic member Pc1 and the platen 10. As the platen 10 and the holder 20 rotate, a mechanochemical reaction between the abrasive grains contained in the dispersion liquid Ld and the ceramic member Pc progresses, polishing the ceramic member Pc. In this embodiment, the dispersion liquid Ld spreads over the surface 11 of the platen 10, and as shown in FIG. 4, a portion Pc10 of the ceramic member Pc1 is immersed in the dispersion liquid Ld. In the method for manufacturing the ceramic member Pc1 of this embodiment, the dispersion liquid Ld is supplied between the ceramic member Pc1 and the platen 10 so that the ceramic member Pc1 is immersed in the dispersion liquid Ld, as shown in FIG. 4. This makes it possible to prevent a shortage of abrasive grains between the ceramic member Pc1 and the surface plate 10.

[0025] 5 is a flowchart of a method for manufacturing a ceramic member according to this embodiment. Next, a method for manufacturing the ceramic member Pc1 will be described. First, in a "preparation step," the ceramic member Pc1, a dispersion Ld in which abrasive grains that undergo a mechanochemical reaction with the ceramic member Pc1 are dispersed, and a surface plate 10 are prepared (step S1). In step S1 of this embodiment, the ceramic member Pc1 made of silicon nitride, the dispersion Ld containing abrasive grains made of iron oxide, and the surface plate 10 containing iron are prepared.

[0026] In preparing the ceramic member Pc1 in step S1, first, ceramic particles made of silicon nitride and a sintering aid are placed in a ball mill together with ethanol, and the mixture is ground and mixed for a predetermined time to produce a slurry. Next, the produced slurry is used to form a roughly spherical compact. Next, the compact is heated and fired under predetermined conditions to produce the ceramic member Pc1 before polishing. In step S1, the ceramic member Pc1 before polishing is set in the holder 20 of the polishing apparatus 1.

[0027] In preparing the dispersion liquid Ld in step S1, abrasive grains formed from iron oxide are mixed with an alkaline liquid containing water and a small amount of coolant liquid. In this embodiment, the liquid and abrasive grains are mixed so that the weight ratio of the abrasive grains to the liquid in the dispersion liquid Ld is 20%. In step S1, the dispersion liquid Ld is poured into the storage tank 31 of the dispersion liquid supply unit 30.

[0028] The surface plate 10 prepared in step S1 is not hardened, contains iron, and has iron oxide on the surface 11. In step S1, the surface plate 10 is set in the polishing apparatus 1 so as to be connected to the first drive unit 1b of the polishing apparatus 1.

[0029] Next, in the "polishing step," the ceramic member Pc1 is polished while pressing the ceramic member Pc1 against the surface plate 10 while the dispersion liquid Ld is supplied between the ceramic member Pc1 and the surface plate 10 (step S2). In step S2, the polishing apparatus 1 is operated to continuously supply the dispersion liquid Ld between the surface plate 10 and the ceramic member Pc1 supported by the holder 20 while rotating the surface plate 10 and the holder 20. At this time, the dispersion liquid Ld is supplied between the ceramic member Pc1 and the surface plate 10 so that the ceramic member Pc1 is immersed in the dispersion liquid Ld. This reduces the shortage of abrasive grains between the ceramic member Pc1 and the surface plate 10, ensuring the mechanochemical reaction between the ceramic member Pc1 and the abrasive grains. Therefore, the surface of the ceramic member Pc1 is polished to a mirror finish with few voids or scratches. The method for manufacturing the ceramic member Pc1 of this embodiment produces the ceramic member Pc1 in this manner. In addition, "a state in which the dispersion liquid Ld is supplied between the ceramic member Pc1 and the surface plate 10" includes not only a state in which the dispersion liquid Ld continues to be supplied between the ceramic member Pc1 and the surface plate 10, but also a state in which the dispersion liquid Ld remains between the ceramic member Pc1 and the surface plate 10 even after the supply of the dispersion liquid Ld itself has finished.

[0030] Next, an evaluation test for the manufacturing method of the ceramic member will be described. In this evaluation test, ceramic members were polished using samples of dispersions with different abrasive grain content in the same manner as in the polishing method for the ceramic member Pc of the first embodiment, and the relationship between the quality of the polished surface of the ceramic member, the polishing efficiency, and the abrasive grain content was evaluated.

[0031] FIG. 6 is the first diagram illustrating an evaluation test of a manufacturing method for a ceramic member. FIG. 6 shows the weights of the liquid and abrasive grains in the dispersion samples used in this evaluation test, as well as the weight ratio of abrasive grains to liquid in the dispersion (abrasive grain amount ratio). Five types of samples with different abrasive grain content were prepared for this evaluation test. Specifically, dispersions were prepared by adding 0 g (Sample 1), 50 g (Sample 2), 100 g (Sample 3), 200 g (Sample 5), or 250 g (Sample 6) of abrasive grains to 500 g of liquid. As a result, the "abrasive grain amount ratio" was 0% (Sample 1), 10% (Sample 2), 20% (Sample 3), 40% (Sample 4), or 50% (Sample 5).

[0032] FIG. 7 is a second diagram illustrating the evaluation test of the manufacturing method for ceramic members. FIG. 7 shows the polishing efficiency and the quality of the polished surface when ceramic members were polished using each of Samples 1 to 4. In FIG. 7, the horizontal axis represents the abrasive grain ratio (unit: %) of the dispersion (see FIG. 6). The vertical axis of FIG. 7 represents the "removal stock (unit: μm / h)" indicated by black circles and a solid line, and the "surface roughness Ra (unit: μm)" indicated by white circles and a chain line. As shown in FIG. 7, in the dispersion with an abrasive grain ratio of 0% (Sample 1), the mechanochemical reaction between silicon nitride and iron oxide did not proceed. Therefore, it was confirmed that, among the samples used in this evaluation test, the surface roughness Ra was the largest and the removal stock was the smallest. In other words, the quality of the polished surface of the ceramic member was the poorest, and the polishing time was long, confirming that the polishing efficiency was relatively low. It was confirmed that when the abrasive grain ratio was greater than 0%, the surface roughness Ra decreased and the removal rate increased. Therefore, it was confirmed that when polishing using Samples 2 to 4, the quality of the polished surface of the ceramic member was improved compared to polishing using Sample 1, and the polishing efficiency was also improved. In particular, with dispersions (Samples 2 to 4) having an abrasive grain ratio of 10% or more and 40% or less, the surface roughness Ra was below a certain value, and it was confirmed that the quality of the polished surface of the ceramic member could be maintained even if the abrasive grain ratio in the dispersion changed.

[0033] Fig. 8 is a third diagram illustrating an evaluation test of the manufacturing method of a ceramic member. Fig. 8 shows the results of judging the surface condition of the ceramic members polished using each of Samples 1 to 5. The "judgment results" shown in Fig. 8 were categorized as follows based on the number of voids and scratches of 10 μm or less within a 0.5 mm square area, which were imaged using a scanning electron microscope (SEM) on the surface of the ceramic member after polishing. ◎:0 pieces 〇: Less than 5 pieces ×:6 or more

[0034] The evaluation results shown in Figure 8 confirm that Sample 1, with an abrasive grain ratio of 0%, and Sample 5, with an abrasive grain ratio of 50%, have five or more voids or scratches, resulting in an unacceptable evaluation of "X" for the product. This is thought to be because Sample 5, with an abrasive grain ratio of 50%, has an excessively high abrasive grain ratio, which makes it easier for abrasive grains to remain between the platen and the ceramic member even when the platen or ceramic member rotates, destabilizing the mechanochemical reaction. On the other hand, Samples 2 to 4, with an abrasive grain ratio of 10% to 40% and less, were evaluated as acceptable products, with an evaluation of "Good" or "Excellent." Thus, it was confirmed that a relatively large number of voids and scratches were formed on the surface of the ceramic member when the abrasive grain ratio was greater than 0% or 40%.

[0035] FIG. 9 is the fourth diagram illustrating the evaluation test of the manufacturing method of a ceramic member. FIG. 9 shows an SEM image of the surface of a ceramic member polished using Sample 4, which has an abrasive grain ratio of 40%. In FIG. 9, voids or scratches observed on the surface of the ceramic member are indicated by a dotted ellipse E1. As shown in FIG. 9, the surface of the ceramic member polished using the dispersion of Sample 4 has relatively few voids or scratches, confirming that good polishing was achieved due to the progress of a mechanochemical reaction between the silicon nitride of the ceramic member and the iron oxide of the abrasive grains.

[0036] According to the manufacturing method of the ceramic member Pc1 of this embodiment described above, the weight ratio of abrasive grains to the liquid in the dispersion Ld supplied between the ceramic member Pc1 and the surface plate 10 in the polishing process of step S2 is 20%, which is greater than 0% and not greater than 40%. In the polishing process, with the dispersion Ld supplied between the ceramic member Pc1 and the surface plate 10, the ceramic member Pc1 is polished while being pressed against the surface plate 10. This prevents a shortage of abrasive grains between the ceramic member Pc1 and the surface plate 10, ensuring the mechanochemical reaction between the ceramic member Pc1 and the abrasive grains. Therefore, the polishing time can be shortened while maintaining the quality of the polished surface of the ceramic member Pc1, thereby achieving both high polishing surface quality and high polishing efficiency.

[0037] Furthermore, according to the method for manufacturing the ceramic member Pc1 of this embodiment, in the polishing process of step S2, the ceramic member Pc1 is immersed in the dispersion liquid Ld, which can prevent abrasive grain breakage on the polished surface of the ceramic member Pc1. Here, "immersing" includes immersing a portion Pc10 of the ceramic member Pc1 in the dispersion liquid Ld, as shown in FIG. 4. This ensures that the mechanochemical reaction between the ceramic member Pc1 and the abrasive grains proceeds, thereby further improving the polishing efficiency while maintaining the quality of the polished surface.

[0038] Furthermore, according to the method for manufacturing the ceramic member Pc1 of this embodiment, the ceramic member Pc1 made of silicon nitride and the dispersion liquid Ld containing abrasive grains made of iron oxide are prepared in the preparation process of step S1, which makes it possible to achieve both high quality of the polished surface of the ceramic member Pc1 made of silicon nitride and high polishing efficiency.

[0039] Furthermore, according to the manufacturing method of the ceramic member Pc1 of this embodiment, in the preparation step of step S1, a surface platen 10 having iron oxide on its surface 11 is prepared. As a result, when the ceramic member Pc1 made of silicon nitride is polished in the polishing step of step S2, the abrasive grains supplied together with the dispersion liquid Ld are more likely to be held by the iron oxide on the surface 11 of the surface platen 10, and if there are insufficient abrasive grains, a mechanochemical reaction between the iron oxide on the surface platen 10 and the silicon nitride of the ceramic member Pc1 proceeds. Therefore, when the ceramic member Pc1 made of silicon nitride is polished, the loss of iron oxide can be further suppressed, thereby suppressing a deterioration in the quality of the polished surface.

[0040] Furthermore, according to the manufacturing method of the ceramic member Pc1 of this embodiment, in the preparation process of step S1, an unhardened surface plate 10 is prepared. This makes it easier for the surface plate 10 to retain the dispersion liquid on the surface 11, which makes it easier to suppress abrasive grain breakage on the polishing surface of the ceramic member Pc1, making it easier to achieve both quality of the polishing surface of the ceramic member Pc1 made of silicon nitride and polishing efficiency.

[0041] Furthermore, according to the method for manufacturing the ceramic member Pc1 of this embodiment, in the polishing step S2, the ceramic member Pc1 is polished by rotating both the ceramic member Pc1 and the surface plate 10. This can improve the polishing efficiency.

[0042] Second Embodiment 10 is a partial schematic view of a polishing apparatus used in the method for manufacturing a ceramic member according to the second embodiment. The polishing apparatus 2 used in the method for manufacturing a ceramic member according to the second embodiment has a different shape of the platen compared to the polishing apparatus 1 (FIG. 1) according to the first embodiment.

[0043] The polishing apparatus 2 of this embodiment includes a pair of platens 40, 50 and a dispersion liquid supply unit 60. The polishing apparatus 2 of this embodiment can simultaneously polish multiple spherical ceramic members Pc2. The ceramic members Pc2 polished by the polishing apparatus 2 of this embodiment are made of silicon nitride. FIG. 10 shows a portion of the polishing apparatus 2. In FIG. 10, the polishing apparatus 2 installed to polish the ceramic members Pc2 shows a z-axis that indicates the z-axis direction along the vertical direction, and an x-axis and a y-axis that indicate the x-axis and y-axis directions that are horizontal and perpendicular to each other.

[0044] The pair of surface plates 40, 50 are formed in a substantially circular plate shape. Each of the surface plates 40, 50 has a concave surface 41, 51. In this embodiment, the surface plate 40 has a groove 42 formed around the entire periphery of the outer periphery of the surface 41. The surface plate 50 has a concave surface 51. The surface plate 50 has a groove 52 formed around the entire periphery of the surface 51. The surface plates 40 and 50 are arranged so that the surfaces 41 and 51 face each other. Each of the surface plates 40, 50 has iron oxide formed on the surfaces 41, 51 and is not hardened. In the method for manufacturing a ceramic member of this embodiment, as shown in FIG. 10 , the spherical ceramic member Pc2 is sandwiched between the groove 42 of the surface plate 40 and the groove 52 of the surface plate 50, and the ceramic member Pc2 is polished.

[0045] The dispersion supply unit 60 includes a storage tank (not shown) that stores the dispersion, a supply hose 62 that supplies the dispersion stored in the storage tank, and a dispersion flow path 63 formed inside the surface platen 50 that supplies the dispersion supplied by the supply hose 62 between the surface platen 40 and the surface platen 50. The dispersion of this embodiment is similar to the dispersion Ld of the first embodiment, in that abrasive grains formed of iron oxide that mechanochemically reacts with silicon nitride of the ceramic member Pc2 are dispersed in a liquid. In the dispersion of this embodiment, the weight ratio of abrasive grains to liquid in the dispersion is greater than 0% and equal to or less than 40%.

[0046] The dispersion supply unit 60 supplies the dispersion stored in a storage tank between the surface plates 40 and 50 via a supply hose 62 and a dispersion flow path 63. The abrasive grains contained in the dispersion supplied between the surface plates 40 and 50 undergo a mechanochemical reaction with the silicon nitride of the ceramic member Pc2 between the surface 41 of the surface plate 40 and the surface 51 of the surface plate 50 and the spherical ceramic member Pc2, thereby progressing the polishing of the ceramic member Pc2. In the polishing apparatus 2 of this embodiment, the dispersion grains tend to accumulate in the grooves 42 of the surface plate 40, making it difficult for the abrasive grains to run short (see the dispersion Ld shown in FIG. 10 ). The configuration of the dispersion supply unit 60 in the polishing apparatus 2 is not limited to this.

[0047] In the method for manufacturing a ceramic member of this embodiment, similarly to the first embodiment, a "preparation step" includes preparing a spherical ceramic member Pc2, a dispersion liquid in which abrasive grains that undergo a mechanochemical reaction with the ceramic member Pc2 are dispersed, and a pair of surface plates 40, 50. In a "polishing step," with the dispersion liquid supplied between the ceramic member Pc2 and the pair of surface plates 40, 50, the ceramic member Pc2 is polished while being pressed against each of the pair of surface plates 40, 50.

[0048] In the "polishing step" of this embodiment, the ceramic member Pc2 is sandwiched between the surfaces 41, 51 of the pair of surface plates 40, 50, and the pair of surface plates 40, 50 is moved at different speeds to polish the ceramic member Pc2. For example, the surface plate 40 is rotated while remaining fixed. As a result, the ceramic member Pc2 rotates between the pair of surface plates 40, 50, and the entire surface of the spherical ceramic member Pc2 can be polished evenly.

[0049] According to the manufacturing method of the ceramic member Pc2 of this embodiment described above, the weight ratio of abrasive grains to the liquid in the dispersion liquid supplied between the ceramic member Pc2 and the pair of surface plates 40, 50 in the polishing process is greater than 0% and less than 40%. This prevents a shortage of abrasive grains between the ceramic member Pc2 and the surface plates 40, 50, ensuring the mechanochemical reaction between the ceramic member Pc2 and the abrasive grains. This makes it possible to achieve both high quality of the polished surface of the ceramic member Pc2 and high polishing efficiency.

[0050] Furthermore, according to the method for manufacturing the ceramic member Pc2 of this embodiment, the pair of surface plates 40, 50 sandwiching the spherical ceramic member Pc2 move at different speeds, causing the ceramic member Pc2 to rotate between the pair of surface plates 40, 50. This allows the surface of the ceramic member Pc2 to be polished evenly. Furthermore, as shown in FIG. 10, the dispersion liquid Ld tends to accumulate in the recessed shapes (grooves 42) in the surface 41 of the surface plate 40, making it difficult for abrasive grains to run out. This makes it easier to achieve both high quality of the polished surface and high polishing efficiency.

[0051] <Third embodiment> 11 is a schematic diagram of a polishing apparatus used in the method for manufacturing a ceramic member according to the third embodiment. The polishing apparatus 3 used in the method for manufacturing a ceramic member according to the third embodiment differs from the polishing apparatus 1 (FIG. 1) according to the first embodiment in that a buff is provided on the surface plate.

[0052] The polishing apparatus 3 of this embodiment includes a surface plate 10, a holder 20, a dispersion liquid supply unit 30, and a buff 12. As shown in FIG. 11, the buff 12 is provided on the surface 11 of the surface plate 10. The buff 12 is made of a relatively soft material such as cotton or wool, and is porous. This allows the dispersion liquid, which is supplied by the dispersion liquid supply unit 30 and has a 20% weight ratio of abrasive grains to liquid, to be easily retained.

[0053] In the manufacturing method of the ceramic member Pc1 of this embodiment, similarly to the first embodiment, in a "preparation step," a spherical ceramic member Pc1, a dispersion liquid in which abrasive grains that undergo a mechanochemical reaction with the ceramic member Pc1 are dispersed, and a surface plate 10 on which a buff 12 is provided are prepared. In a "polishing step," the ceramic member Pc1 is polished while being pressed against the buff 12 with the dispersion liquid supplied between the ceramic member Pc1 and the buff 12.

[0054] In the "polishing step" of this embodiment, the ceramic member Pc1 is polished using abrasive grains contained in the dispersion liquid held in the buff 12. This makes it even less likely that abrasive grains will be in short supply during the polishing step. Therefore, the method for manufacturing the ceramic member Pc1 of this embodiment can reliably promote the mechanochemical reaction between the abrasive grains and the ceramic member Pc1.

[0055] According to the method for manufacturing a ceramic member of this embodiment described above, the weight ratio of abrasive grains to the liquid in the dispersion liquid supplied between the ceramic member Pc1 and the platen 10 in the polishing step is 20%. This prevents a shortage of abrasive grains between the ceramic member Pc1 and the platen 10, ensuring the mechanochemical reaction between the ceramic member Pc1 and the abrasive grains. This makes it possible to achieve both high quality of the polished surface of the ceramic member Pc1 and high polishing efficiency.

[0056] Furthermore, according to the manufacturing method of the ceramic member Pc1 of this embodiment, in the preparation step, the platen 10 having the buff 12 provided thereon is prepared, and in the polishing step, the ceramic member Pc1 is polished while pressing the ceramic member Pc1 against the buff 12 in a state in which a dispersion liquid is supplied between the ceramic member Pc1 and the buff 12. This makes it easier for the buff 12 to retain the dispersion liquid, which makes it easier to suppress abrasive grain breakage on the polished surface of the ceramic member Pc1, and makes it easier to achieve both quality of the polished surface of the ceramic member Pc1 made of silicon nitride and polishing efficiency.

[0057] <Modification of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0058] [Variation 1] In the above embodiment, the weight ratio of the abrasive grains to the liquid in the dispersion liquid is 20%. The weight ratio of the abrasive grains to the liquid in the dispersion liquid may be greater than 0% and less than or equal to 40%.

[0059] [Variation 2] In the above-described embodiment, the dispersion liquid is continuously supplied between the platen and the ceramic member in the polishing process. However, the method of supplying the dispersion liquid between the platen and the ceramic member is not limited to this. Intermittent dripping is also acceptable as long as the dispersion liquid is present between the platen and the ceramic member.

[0060] [Variation 3] In the above-described embodiment, the ceramic member is made of silicon nitride, and the abrasive grains are made of iron oxide. However, the relationship between the materials of the ceramic member and the abrasive grains is not limited to this. Any relationship may be used as long as a mechanochemical reaction between the ceramic member and the abrasive grains proceeds.

[0061] [Variation 4] In the above-described embodiment, the surface plate includes iron oxide and is not hardened. The properties of the surface plate are not limited to this. It may not include iron oxide, or may be hardened. When the surface plate includes iron oxide, not only does the abrasive grains become more easily retained on the surface plate, but also, even if there is a shortage of abrasive grains, a mechanochemical reaction between the iron oxide included in the surface plate and the silicon nitride of the ceramic member proceeds, thereby achieving both the quality of the polishing surface and the polishing efficiency. When the surface plate is hardened, the dispersion liquid becomes more easily retained on the surface plate, thereby achieving both the quality of the polishing surface and the polishing efficiency.

[0062] [Variation 5] In the first and third embodiments, both the surface plate 10 and the ceramic member Pc1 rotate. In the second embodiment, the surface plate 50 is fixed, and the surface plate 40 is rotated, thereby rotating the ceramic member Pc2. The direction of movement of the ceramic member relative to the surface plate is not limited to this. In the second embodiment, the pair of surface plates 40, 50 may rotate at different movement speeds, or, for example, the ceramic member may move back and forth in a straight line relative to the surface plate.

[0063] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0064] <Application example 1> A method for manufacturing a ceramic member, comprising: a preparation step of preparing a ceramic member, a dispersion in which abrasive grains that undergo a mechanochemical reaction with the ceramic member are dispersed, and a surface plate; a polishing step of polishing the ceramic member while pressing the ceramic member against the surface plate while the dispersion liquid is supplied between the ceramic member and the surface plate, In the dispersion liquid, the weight ratio of the abrasive grains to the liquid is greater than 0% and less than 40%. A method for manufacturing a ceramic component. <Application example 2> A method for producing a ceramic member according to Application Example 1, comprising: In the polishing step, the dispersion liquid is supplied between the ceramic member and the surface plate so that the ceramic member is immersed in the dispersion liquid. A method for manufacturing a ceramic component. <Application example 3> A method for producing a ceramic member according to Application Example 1 or Application Example 2, The method is characterized in that, in the preparation step, the ceramic member made of silicon nitride and the dispersion liquid containing the abrasive grains made of iron oxide are prepared. A method for manufacturing a ceramic component. <Application Example 4> A method for manufacturing a ceramic member according to any one of Application Examples 1 to 3, In the preparation step, the surface plate having iron oxide on its surface is prepared. A method for manufacturing a ceramic component. <Application example 5> A method for producing a ceramic member according to any one of Application Examples 1 to 4, In the preparation step, the surface plate is prepared which has not been hardened. A method for manufacturing a ceramic component. <Application Example 6> A method for producing a ceramic member according to any one of Application Examples 1 to 5, In the preparation step, the surface plate provided with a buff is prepared, In the polishing step, the ceramic member is polished while being pressed against the buff while the dispersion is supplied between the ceramic member and the buff. A method for manufacturing a ceramic component. <Application Example 7> A method for producing a ceramic member according to any one of Application Examples 1 to 6, In the polishing step, at least one of the ceramic member and the surface plate is rotated to polish the ceramic member. A method for manufacturing a ceramic component. <Application Example 8> A method for producing a ceramic member according to any one of Application Examples 1 to 7, In the preparation step, the ceramic member having a spherical shape and a pair of surface plates having concave surfaces are prepared, In the polishing step, the ceramic member is sandwiched between the surfaces of the pair of surface plates, and the pair of surface plates are moved at different speeds to polish the ceramic member. A method for manufacturing a ceramic component. [Explanation of symbols]

[0065] 1,2,3…polishing equipment Pc1, Pc2...ceramic components Ld…dispersion liquid 10, 40, 50...Surface plate 11,41,51…Surface 12...Buff

Claims

1. A method for manufacturing a ceramic member, comprising: a preparation step of preparing a ceramic member, a dispersion in which abrasive grains that undergo a mechanochemical reaction with the ceramic member are dispersed, and a surface plate; a polishing step of polishing the ceramic member while pressing the ceramic member against the surface plate while the dispersion liquid is supplied between the ceramic member and the surface plate, In the dispersion liquid, the weight ratio of the abrasive grains to the liquid is greater than 0% and less than 40%. A method for manufacturing a ceramic component.

2. 2. The method for manufacturing a ceramic member according to claim 1, In the polishing step, the dispersion liquid is supplied between the ceramic member and the surface plate so that the ceramic member is immersed in the dispersion liquid. A method for manufacturing a ceramic component.

3. 3. The method for producing a ceramic member according to claim 1 or 2, The method is characterized in that, in the preparation step, the ceramic member made of silicon nitride and the dispersion liquid containing the abrasive grains made of iron oxide are prepared. A method for manufacturing a ceramic component.

4. 4. The method for producing a ceramic member according to claim 3, In the preparation step, the surface plate having iron oxide on its surface is prepared. A method for manufacturing a ceramic component.

5. 5. The method for producing a ceramic member according to claim 4, In the preparation step, the surface plate is prepared which has not been hardened. A method for manufacturing a ceramic component.

6. 3. The method for producing a ceramic member according to claim 1 or 2, In the preparation step, the surface plate provided with a buff is prepared, In the polishing step, the ceramic member is polished while being pressed against the buff while the dispersion is supplied between the ceramic member and the buff. A method for manufacturing a ceramic component.

7. 3. The method for producing a ceramic member according to claim 1 or 2, In the polishing step, at least one of the ceramic member and the surface plate is rotated to polish the ceramic member. A method for manufacturing a ceramic component.

8. 3. The method for producing a ceramic member according to claim 1 or 2, In the preparation step, the ceramic member having a spherical shape and a pair of surface plates having concave surfaces are prepared, In the polishing step, the ceramic member is sandwiched between the surfaces of the pair of surface plates, and the pair of surface plates are moved at different speeds to polish the ceramic member. A method for manufacturing a ceramic component.

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