Ceramics member and producing method thereof

Abstract

To provide a producing method of a ceramics member provided with an oxide ceramics sintering portion suppressed in generation of cracks accompanying sintering and having precise composition.SOLUTION: A method for producing a ceramic member 20 includes a step of irradiating at least a part of a precursor molded body 12 containing particles of oxide ceramics for sintering and a sintering aid containing a metal fluoride with a laser to sinter the oxide ceramics for sintering of the laser irradiation portion. The wavelength of the laser is preferably 350 to 2500 nm, and the output is preferably 1 to 1000 W / cm2. When a precursor molded body containing alumina as the oxide ceramics for sintering and yttrium fluoride as the metal fluoride is used, a ceramic member is obtained that includes a main phase made of alumina crystals and a grain boundary phase formed between the alumina crystals, and the ceramics member provided with an alumina sintering portion with the grain boundary phase including Y3Al5O12 is obtained.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a ceramic member having an oxide ceramic sintered portion by using a laser, and to a ceramic member obtained by the method. [Background technology]

[0002] Ceramic members including ceramic sintered bodies are widely used in substrates for various electronic products, heat-resistant members, tools, etc. because they have excellent electrical conductivity or electrical insulation, heat resistance, mechanical properties, corrosion resistance, wear resistance, etc.

[0003] For example, a method for producing a plate-shaped ceramic sintered body is known in which a slurry, paste or powder is prepared by mixing ceramic particles with a binder solution in which a polymer binder is dissolved in a medium, and the resulting mixture is subjected to press molding, slurry casting, injection molding, extrusion molding, screen printing or the like, and then sintered.

[0004] As another manufacturing method, Patent Document 1 discloses a method for producing an alumina ceramic sintered body in which an alumina ceramic sintered body is obtained by spark plasma sintering an alumina powder, characterized in that the alumina powder is an activated alumina powder obtained by thermally decomposing basic aluminum chloride. Patent Document 2 discloses a method for producing an alumina ceramic sintered body, which comprises adding bismuth oxide to alumina powder in a ratio of 0.1 to 5.0 mass %, compression molding the mixed powder, and sintering the molded body at a temperature at which the bismuth oxide melts.

[0005] In recent years, in order to shorten manufacturing times, methods of manufacturing ceramic members by sintering ceramic materials using a laser have been investigated.

[0006] Patent Document 3 discloses a method for producing an article having a sintered portion, characterized by sequentially including a step of forming a carbon powder-containing layer made of graphite and having a thickness of 100 nm to 10 μm by spraying graphite onto the surface of a non-sintered portion of an article having the non-sintered portion made of an oxide as a sintering ceramic, and a step of irradiating a laser onto the surface of the carbon powder-containing layer in the obtained laminate to sinter the oxide located on the underlying side of the irradiated portion. Furthermore, Patent Document 4 discloses a method for producing a ceramic sintered body, including a mixing step of mixing ceramic powder and carbon powder to obtain a mixed powder, a molding step of molding the mixed powder to obtain a molded body, and a sintering step of irradiating the molded body with laser light to form a ceramic sintered part. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2003-277133 A [Patent Document 2] JP 2005-330136 A [Patent Document 3] Patent No. 6956489 [Patent Document 4] Patent Publication No. 2023-29060 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a method for producing a ceramic member including an oxide ceramic sintered portion having a dense structure and in which the generation of cracks due to sintering is suppressed. [Means for solving the problem]

[0009] The present invention is illustrated below. 1. A method for manufacturing a ceramic member, comprising the steps of irradiating with a laser at least a portion of a precursor molded body containing particles of oxide ceramics for sintering and a sintering aid containing a metal fluoride, and sintering the oxide ceramics for sintering in the laser irradiated portion. 2. The wavelength of the laser is 350-2500 nm and the output is 1-1000 W / cm 2 2. The method for producing a ceramic member according to item 1, 3. The above metal fluoride is calcium fluoride, barium fluoride, aluminum fluoride, scandium fluoride, yttrium fluoride, lanthanum fluoride, zinc fluoride, cobalt fluoride, lead fluoride, gallium fluoride, indium fluoride, silver fluoride, chromium fluoride, iron fluoride, nickel fluoride, hafnium fluoride, copper fluoride, bismuth fluoride, manganese fluoride, tin fluoride, antimony fluoride, titanium fluoride, Item 2. A method for producing a ceramic member according to item 1, wherein the fluoride is at least one selected from the group consisting of niobium fluoride, tantalum fluoride, cerium fluoride, praseodymium fluoride, neodymium fluoride, promethium fluoride, samarium fluoride, europium fluoride, gadolinium fluoride, terbium fluoride, dysprosium fluoride, holmium fluoride, erbium fluoride, thulium fluoride, ytterbium fluoride and lutetium fluoride. 4. The method for producing a ceramic member according to item 1, wherein the content of the oxide ceramic particles for sintering and the sintering aid constituting the precursor molded body is 90 to 97% by volume and 3 to 10% by volume, respectively, when the total of the two is taken as 100% by volume. 5. The method for producing a ceramic member according to item 1, wherein the oxide ceramic particles for sintering are alumina particles, and the metal fluoride is yttrium fluoride. 6. A ceramic member obtained by the method according to the above item 5, the ceramic member having a main phase made of alumina crystals and a grain boundary phase formed between the alumina crystals, the grain boundary phase being Y3A l5 O 12 A ceramic member comprising a portion made of an alumina sintered body containing the above-mentioned compound. 7. The method for producing a ceramic member according to item 1, wherein the oxide ceramic particles for sintering are alumina particles, and the metal fluoride is barium fluoride. 8. The method for producing a ceramic member according to item 1, wherein the oxide ceramic particles for sintering are yttria-stabilized zirconia particles, and the metal fluoride is yttrium fluoride. Effect of the Invention

[0010] According to the method for manufacturing a ceramic member of the present invention, the occurrence of cracks due to sintering is suppressed, and a ceramic member including an oxide ceramic sintered portion having a dense structure can be efficiently manufactured. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a ceramic member manufacturing method of the present invention, in which (A) is an example of a ceramic member manufacturing apparatus, and (B) and (C) are examples of ceramic members having an oxide ceramic sintered portion obtained after manufacturing. [Diagram 2] 1 is a schematic cross-sectional view showing an example of a method for producing a ceramic member having a three-dimensional structure. [Diagram 3] 1 is an image showing the surface of the ceramic member (S1) obtained in Example 1. [Figure 4] 1 is an image showing the inside of the ceramic member (S1) obtained in Example 1. [Diagram 5] This is an enlarged image of Figure 4. [Figure 6] 2 shows X-ray diffraction images of a precursor shaped body before laser irradiation and a ceramic member (S1) after laser irradiation in Example 1. [Figure 7] 1 is an image showing the inside of a ceramic member (S2) obtained in Example 2. [Figure 8] FIG. 8 is an enlarged image of FIG. [Figure 9] 1 is an image showing the inside of a ceramic member (S3) obtained in Example 3. [Figure 10] FIG. 10 is an enlarged image of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The method for producing a ceramic member of the present invention includes a step of irradiating with a laser at least a part of a precursor molded body containing particles of oxide ceramics for sintering (hereinafter referred to as "oxide ceramic particles for sintering") and a sintering aid containing a metal fluoride, and sintering the oxide ceramics for sintering in the laser irradiated part (hereinafter referred to as "laser irradiation step"). The method for producing a ceramic member of the present invention can further include an adjustment step of performing correction such as surface polishing after the laser irradiation step. A typical method for manufacturing a ceramic member will be described below with reference to FIG.

[0013] FIG. 1(A) is a schematic diagram of a ceramic member manufacturing apparatus 10 that irradiates a laser oscillated from a laser light source 14 onto the surface of a precursor molded body 12 containing oxide ceramic particles for sintering and a sintering aid containing a metal fluoride. For example, when a laser having a wavelength of 350 to 2500 nm is irradiated onto the oxide ceramic for sintering and the metal fluoride, the energy absorption rate of the laser is higher for the metal fluoride. Therefore, when the laser is irradiated onto the precursor molded body 12, the laser irradiated portion of the precursor molded body 12 instantly reaches a temperature at which the oxide ceramic for sintering is sintered, and for example, a sintered portion 16 shown in FIG. 1(B) is formed. The non-laser irradiated portion is the non-sintered portion 15, and the composition of the non-sintered portion 15 is the same as that of the precursor molded body 12. The ceramic member 20 according to the present invention may be composed of the sintered portion 16 and the non-sintered portion 15 as shown in FIG. 1(B), or may be composed of only the sintered portion 16 without the non-sintered portion 15 as shown in FIG. 1(C). Furthermore, while FIG. 1(B) shows a ceramic member 20 in which the entire cross-sectional area of ​​the laser-irradiated portion is a sintered portion 16, the ceramic member of the present invention may also be one in which only the surface layer of the laser-irradiated portion of the precursor molded body 12 is made into the sintered portion 16 (not shown).

[0014] The oxide constituting the oxide ceramic particles for sintering is not particularly limited, and examples thereof include aluminum oxide, mullite, magnesium oxide, zinc oxide, titanium oxide, iron oxide, yttrium oxide, zirconium oxide, stabilized zirconia, and barium titanate.

[0015] The shape and size of the sintering ceramic oxide particles are not particularly limited. The particle shape can be a solid body, such as a sphere, an oval sphere, a polyhedron, a line, a plate, or an irregular shape. The particle diameter is preferably 10 nm to 100 μm, more preferably 100 nm to 10 μm. The sintering ceramic oxide particles contained in the precursor molded body 12 preferably have a wide particle size distribution within the above range. For example, when the precursor molded body 12 contains two or more kinds of sintering ceramic oxide particles having different average particle diameters, the dense ceramic sintered portion 16 can be efficiently formed.

[0016] The sintering aid contains a metal fluoride and may further contain conventionally known sintering aids (hereinafter referred to as "other sintering aids") depending on the type of oxide ceramic for sintering that constitutes the oxide ceramic particles for sintering, but typically consists of one or more types of metal fluorides.

[0017] Metal fluorides include calcium fluoride, barium fluoride, aluminum fluoride, scandium fluoride, yttrium fluoride, lanthanum fluoride, zinc fluoride, cobalt fluoride, lead fluoride, gallium fluoride, indium fluoride, silver fluoride, chromium fluoride, iron fluoride, nickel fluoride, hafnium fluoride, copper fluoride, bismuth fluoride, manganese fluoride, tin fluoride, and Examples of fluoride include antimony, titanium fluoride, niobium fluoride, tantalum fluoride, cerium fluoride, praseodymium fluoride, neodymium fluoride, promethium fluoride, samarium fluoride, europium fluoride, gadolinium fluoride, terbium fluoride, dysprosium fluoride, holmium fluoride, erbium fluoride, thulium fluoride, ytterbium fluoride, and lutetium fluoride. The above metal fluorides are treated with a compound having the general formula MF n(M: metal atom), MF containing M different from the metal atom of the oxide ceramic for sintering that constitutes the oxide ceramic particle for sintering n It is preferable to use:

[0018] The other sintering aids include ceramics that are different from the oxide ceramics for sintering that constitute the oxide ceramic particles for sintering.

[0019] The shape and size of the sintering aid are not particularly limited.

[0020] In order to efficiently form the sintered portion 16, the content ratios of the sintering oxide ceramic particles and sintering aid contained in the precursor molded body 12 before laser irradiation are preferably 90 to 97 volume % and 3 to 10 volume %, more preferably 92 to 96 volume % and 4 to 8 volume %, and even more preferably 93 to 95 volume % and 5 to 7 volume %, respectively, when the total of both is taken as 100 volume %.

[0021] In the method for producing a ceramic member of the present invention, a precursor molded body having a preferred combination of sintering oxide ceramic particles and a sintering aid (metal fluoride) is shown below. (A) A precursor compact in which the oxide ceramic particles to be sintered are alumina particles and the metal fluoride is yttrium fluoride. (a) A precursor compact in which the oxide ceramic particles for sintering are alumina particles and the metal fluoride is barium fluoride. (c) A precursor compact in which the oxide ceramic particles for sintering are yttria-stabilized zirconia particles and the metal fluoride is yttrium fluoride.

[0022] The type of laser to be irradiated onto the precursor molded body 12 containing the oxide ceramic particles for sintering and the sintering aid is not particularly limited, and a solid-state laser, a gas laser, a semiconductor laser, a fiber laser, etc. can be used. Among these, a fiber laser is preferred. A fiber laser is a laser that is transmitted in a state in which a laser is confined in the fiber by generating an induced discharge in a core doped with a rare earth element or the like in an optical fiber. A device that oscillates a fiber laser may be connected to a device that oscillates another laser such as a solid-state laser to form a laser oscillation device with a higher output.

[0023] The conditions for irradiating the precursor molded body 12 with the laser are appropriately selected depending on the type of ceramic constituting the oxide ceramic particles for sintering, the type of sintering aid, the content ratio of the oxide ceramic particles for sintering and the sintering aid, etc.

[0024] The wavelength of the laser is not particularly limited and can be 300 to 10,000 nm, but is preferably 350 to 2,500 nm, and more preferably 500 to 1,500 nm. As described above, when a laser having a wavelength of 350 to 2,500 nm is irradiated, the laser irradiated portion of the precursor molded body 12 instantaneously reaches the sintering temperature, and sintering proceeds. The present inventors believe that when a laser having a wavelength of 350 to 2,500 nm in particular is irradiated to the precursor molded body 12, oxygen in the air or oxygen constituting the oxide ceramic particles for sintering reacts with fluorine in the metal fluoride, and at this time, the laser absorbency is improved for anion deficiency, and the sintering reaction proceeds more easily.

[0025] From the viewpoint of smooth sintering, the laser output is preferably 1 to 1000 W / cm 2 , more preferably 500 to 1000 W / cm 2 It is.

[0026] In the laser irradiation step, there is no particular limitation on the method of irradiating the precursor molded body 12 with a laser. When forming a large-area sintered portion on the precursor molded body 12, a method of irradiating the precursor molded body 12 while scanning it with a laser or changing the optical path via a light diffusion lens in a fixed state, or a method of irradiating the precursor molded body 12 with a laser with a fixed optical path while moving the precursor molded body 12 can be applied.

[0027] When the precursor molded body 12 is irradiated with a laser, the atmosphere is not particularly limited, and may be air, nitrogen, argon, helium, or the like.

[0028] In addition, when irradiating the laser, the precursor molded body 12 may be preheated as necessary. The preheating method is not particularly limited, and may be an infrared lamp, a halogen lamp, resistance heating, high-frequency induction heating, microwave heating, or the like.

[0029] According to the method for producing a ceramic member of the present invention, sintering progresses in the depth direction from the surface of the precursor shaped body 12 irradiated with a laser, and depending on the type of oxide ceramics for sintering contained in the precursor shaped body 12, the formed sintered portion may be laser transparent, and as long as the laser attenuation is not large, sintering can be performed deep into the irradiated portion of the precursor shaped body 12. Therefore, by appropriately setting the laser irradiation conditions, it is possible to obtain a ceramic member 20 having a sintered portion 16 with a dense structure, for example, as shown in FIG. 1(B).

[0030] According to the method for producing a ceramic member of the present invention, it is possible to efficiently produce a ceramic member having an oxide ceramic sintered part with a dense structure without causing cracks that may occur during sintering. The relative density of the sintered part, as measured by Archimedes' method, is preferably 85% or more, more preferably 90% or more.

[0031] In the method for producing a ceramic member of the present invention, when a precursor compact containing alumina particles as the oxide ceramic particles to be sintered and yttrium fluoride as the metal fluoride is used, a ceramic member having a main phase composed of alumina crystals and a grain boundary phase formed between the alumina crystals, the grain boundary phase being YAlO 12The inventors have found that when such a precursor molded body is irradiated with a laser, oxygen in the air or oxygen constituting the alumina particles reacts with fluorine in the yttrium fluoride to form YOF, resulting in an anion deficiency, and therefore laser absorption is improved in the laser irradiated portion, and as the sintering of the alumina progresses, a reaction between the alumina and yttrium oxide progresses at the interfaces between the alumina particles to form Y3Al5O 12 It is believed that a grain boundary phase containing alumina is formed, and a sintered part is obtained in which there are almost no voids between the main phases made of alumina crystals, as shown in Figure 5.

[0032] The method for producing a ceramic member of the present invention can be used to produce a ceramic member made of a shaped object having a three-dimensional structure. An example of a method for producing a shaped object will be described below with reference to FIG.

[0033] FIG. 2 is a schematic diagram showing a method for producing a three-dimensional object 50 shown in FIG. 2(5). Fig. 2(1) is a cross-sectional view showing a thin-walled precursor molded body 31, and first, region R1 shown in Fig. 2(1) is subjected to a laser irradiation process. A sintered portion 35 is formed by irradiating region R1 with a laser, and the area around region R1 is a non-irradiated portion, which becomes non-sintered portions 31A and 31B (see Fig. 2(2)). Next, a thin-walled precursor molded body 41 is placed so as to cover the sintered portion 35, and the region R2 shown in Fig. 2(3) is subjected to a laser irradiation step. The sintered portion 45 is formed by irradiating the region R2 with a laser, and the area around the region R2 is a non-irradiated portion, which becomes non-sintered portions 41A and 41B (see Fig. 2(4)). The formed sintered portion 45 has laser transparency, so it can be integrated with the sintered portion 35, and then, by removing the non-sintered portions 31A, 31B, 41A, and 41B, the molded object 50 shown in Fig. 2(5) can be easily obtained. EXAMPLES

[0034] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0035] In the following experiments, a fiber laser emitting a laser with a wavelength of 1070 nm was used to irradiate a disk-shaped molded body (outer diameter: 15 mm, thickness: 1.8 mm) consisting of α-alumina particles or yttria-stabilized zirconium oxide particles and metal fluoride powder (sintering aid) via a galvanometer mirror.

[0036] Example 1 "AA-3" (trade name, median particle size: 3.5 μm) and "AA-03" (trade name, median particle size: 0.40 μm) from the "Advanced Alumina" series of α-alumina single crystal particles manufactured by Sumitomo Chemical Co., Ltd. were mixed in a volume ratio of 7:3, and then this mixed powder was mixed with yttrium fluoride powder in a volume ratio of 95:5. Thereafter, this mixed raw material was subjected to powder compaction to obtain a disk-shaped compact (hereinafter referred to as "raw material compact (P1)"). Next, the laser power was increased to 1000W / cm 2 The laser was irradiated to the raw material compact (P1) while scanning the entire surface of the raw material compact (P1) at a beam diameter of 8 mm at a speed of 100 mm per second, to obtain a ceramic member (hereinafter referred to as "ceramic member (S1)").

[0037] Figure 2 is a surface image of the ceramic member (S1) taken with an optical microscope; no cracks were observed. The ceramic member (S1) was also broken, and the microstructure inside the ceramic member was observed with an electron microscope (see Figure 4). From Figure 4, it was found that the ceramic member (S1) was composed of a dense sintered body. From Figure 5, an enlarged image of Figure 4, it was found that grain boundary crystal phases were dispersed within the alumina crystal phase. The relative density was measured by the Archimedes method and found to be 92%. Furthermore, when the ceramic member (S1) was subjected to X-ray diffraction measurement, as shown in FIG. 6, the diffraction image of the raw material compact (P1) before the laser irradiation included a pattern of α-alumina and yttrium fluoride, and the diffraction image of the ceramic member (S1) included a pattern of α-alumina and Y3Al5O 12(hereinafter referred to as "YAG") pattern.

[0038] Example 2 A ceramic member (hereinafter referred to as "ceramic member (S2)") was obtained by the same operation as in Example 1, except that barium fluoride powder manufactured by Kojundo Chemical Laboratory was used instead of yttrium fluoride powder, and the volume ratio of the α-alumina single crystal mixed particles and the barium fluoride powder was 90:10. No cracks were observed on the surface. Thereafter, the ceramic member (S2) was broken and the microstructure inside the ceramic member was observed. From Figs. 7 and 8, it was found that the ceramic member (S2) was sufficiently sintered and had a dense structure.

[0039] Example 3 A ceramic member (hereinafter referred to as "ceramic member (S3)") was obtained by the same procedure as in Example 1, except that yttria-stabilized zirconium oxide particles (average particle size: 1 μm) manufactured by Tosoh Corporation were used instead of the α-alumina single crystal mixed particles, and the volume ratio of the yttria-stabilized zirconium oxide particles and the yttrium fluoride powder was set to 95:5. No cracks were observed on the surface. Thereafter, the ceramic member (S3) was broken and the microstructure inside the ceramic member was observed. From Figs. 9 and 10, it was found that the ceramic member (S3) was sufficiently sintered and had a dense structure. [Industrial Applicability]

[0040] According to the method for producing a ceramic member of the present invention, a ceramic member having an oxide ceramic sintered portion with a dense structure can be efficiently produced by irradiating a precursor body with a laser. Such a ceramic member is suitable for use as a substrate for electronic products, a heat-resistant member, a low light reflectance material, a low dielectric loss material, a high-temperature high-strength material, a low friction and low wear material, a tool, etc. [Explanation of symbols]

[0041] 10: Ceramic component manufacturing equipment 12: Precursor compact containing oxide ceramic particles for sintering and sintering aid 14: Laser light source 15: Unsintered part 16: Sintering section 20: Ceramic materials 31: Precursor molded body 31A, 31B: Non-sintered part 35: Sintering section 41: Precursor molded body 41A, 41B: Non-sintered part 45: Sintering section 50: Ceramic components (models) with three-dimensional structures

Claims

1. A method for manufacturing a ceramic member, comprising the steps of irradiating with a laser at least a portion of a precursor molded body containing particles of oxide ceramics for sintering and a sintering aid containing a metal fluoride, and sintering the oxide ceramics for sintering in the laser irradiated portion.

2. The wavelength of the laser is 350 to 2500 nm, and the output is 1 to 1000 W / cm ２ The method for producing a ceramic member according to claim 1,

3. The metal fluoride is selected from the group consisting of calcium fluoride, barium fluoride, aluminum fluoride, scandium fluoride, yttrium fluoride, lanthanum fluoride, zinc fluoride, cobalt fluoride, lead fluoride, gallium fluoride, indium fluoride, silver fluoride, chromium fluoride, iron fluoride, nickel fluoride, hafnium fluoride, copper fluoride, bismuth fluoride, manganese fluoride, tin fluoride, antimony fluoride, titanium fluoride, The method for producing a ceramic member according to claim 1, wherein the fluoride is at least one selected from the group consisting of niobium fluoride, tantalum fluoride, cerium fluoride, praseodymium fluoride, neodymium fluoride, promethium fluoride, samarium fluoride, europium fluoride, gadolinium fluoride, terbium fluoride, dysprosium fluoride, holmium fluoride, erbium fluoride, thulium fluoride, ytterbium fluoride and lutetium fluoride.

4. The method for producing a ceramic member according to claim 1, wherein the content ratios of the sintering oxide ceramic particles and the sintering aid constituting the precursor compact are 90 to 97% by volume and 3 to 10% by volume, respectively, when the total of the two is 100% by volume.

5. 2. The method for producing a ceramic member according to claim 1, wherein the oxide ceramic particles for sintering are alumina particles, and the metal fluoride is yttrium fluoride.

6. A ceramic member obtained by the method according to claim 5, the ceramic member comprising a main phase made of alumina crystals and a grain boundary phase formed between the alumina crystals, the grain boundary phase being Y ３ A ｌ５ O １２ A ceramic member comprising a portion made of an alumina sintered body containing the above-mentioned compound.

7. 2. The method for producing a ceramic member according to claim 1, wherein the oxide ceramic particles for sintering are alumina particles, and the metal fluoride is barium fluoride.

8. 2. The method for producing a ceramic member according to claim 1, wherein the oxide ceramic particles for sintering are yttria-stabilized zirconia particles, and the metal fluoride is yttrium fluoride.

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