JP2023012878A - Fitting body and connection mechanism - Google Patents

Abstract

To provide a fitting body with high thermal insulation and a connecting mechanism having the fitting body.SOLUTION: A first fitting body of the present disclosure includes a columnar body comprising a first ceramic composed mainly of aluminum oxide at least at a tip, and a substrate comprising a second ceramic composed mainly of aluminum oxide having a recess into which the tip is inserted. The tip is fitted into the recess and has a gap between the tip surface of the tip and the inner bottom surface of the recess.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a fitting and a connection mechanism having the fitting.

Conventionally, shrink fitting is used to fit ceramics together. For example, Patent Document 1 proposes a high-pressure discharge lamp in which end caps made of translucent alumina are hermetically joined to both ends of a cylindrical container body made of translucent alumina by shrink fitting to form a discharge space inside. It is

Japanese Patent Application Laid-Open No. 2006-93046

The high-pressure discharge lamp proposed in Patent Document 1 is formed by shrink-fitting ceramics with high thermal conductivity, such as translucent alumina, without gaps. Translucent alumina consists of crystal grains with a large grain size, and the proportion of grain boundary phase that hinders heat conduction is small. Conduction is better. Therefore, there is a problem that the fitted body of translucent alumina is not suitable for applications that require high heat insulation.

An object of the present disclosure is to provide a fitted body with high heat insulation and a connection mechanism having this fitted body.

A first fitting body of the present disclosure for solving the above problems is a columnar body made of a first ceramic whose main component is aluminum oxide at least at the tip, and an aluminum oxide having a recess into which the tip is inserted. and a base made of second ceramics containing as a main component. The tip portion is fitted into the recess, and has a gap between the tip surface of the tip portion and the inner bottom surface of the recess.

A second fitted body of the present disclosure includes a first member having a projection made of a first ceramic containing aluminum oxide as a main component, a base supporting the projection, and a recess into which the projection is inserted. and a second member made of a second ceramic containing aluminum oxide as a main component. The protrusion is fitted into the recess, and has a gap between the tip surface of the protrusion and the inner bottom surface of the recess.

The connection mechanism of the present disclosure has the first or second fitted body.

In the first fitting body of the present disclosure, both the columnar body and the base are made of ceramics mainly composed of aluminum oxide with low thermal conductivity, and the tip of the columnar body is fitted in the recess of the base, Since there is a gap between the tip surface of the tip portion and the inner bottom surface of the recess, heat insulation is improved.
In the second fitted body of the present disclosure, both the first member and the second member are made of ceramics mainly composed of aluminum oxide with low thermal conductivity, and the convex portion of the first member is the same as that of the second member. Since it is fitted in the recess and there is a gap between the tip surface of the protrusion and the inner bottom surface of the recess, heat insulation is improved.
Therefore, the connection mechanism having the first or second fitting is suitable for application to heat insulators.

1 is a perspective view of a thermal insulator having a fitting according to an embodiment of the present disclosure; FIG. FIG. 2 is a partially enlarged sectional view of FIG. 1; 3 is an enlarged cross-sectional view of the fitted body shown in FIG. 2; FIG. FIG. 4 is a cross-sectional view showing a fitted body according to another embodiment of the present disclosure;

A fitting body according to an embodiment of the present disclosure and a connection mechanism having the fitting body will be described below. FIG. 1 shows a plate-like heat insulator 1 having a fitting according to one embodiment of the present disclosure.

As shown in FIG. 2, the heat insulator 1 includes a base body 2 having a rising portion 21 on its peripheral edge and a lid body 3 arranged on the upper surface of the base body 2 . The peripheral edge of the lower surface of the lid 3 is bonded to the upper surface of the rising portion 21 of the base 2 via the first bonding layer 4 , and an internal space 5 is formed between the base 2 and the lid 3 . By maintaining the interior space 5 in a vacuum state by vacuum heating treatment or the like, the heat insulator 1 is provided with high heat insulating properties.

A plurality of columnar bodies 6 are arranged at predetermined intervals in the internal space 5 of the heat insulating body 1 so as to withstand the reduced pressure. The columnar body 6 is interposed between the base body 2 and the lid body 3 to maintain a constant gap between the base body 2 and the lid body 3 .
The internal space 5 functions as a heat insulating layer. The width W of the internal space 5 is preferably 10 mm or more and 60 mm or less. The thickness of the base body 2 and the cover body 3 is preferably 10 mm or more and 30 mm or less.

FIG. 3 shows an example of a fitted body in which the columnar body 6 is fitted in the concave portion 7. As shown in FIG. As shown in FIG. 3, a recess 7 is formed in the inner surface of the lid 3, and the tip of the columnar body 6 is inserted into the recess 7. As shown in FIG. The columnar body 6 is fitted into the recess 7 , and the heat insulator 1 has a gap 8 between the tip surface of the columnar body 6 and the inner bottom surface of the recess 7 . This improves heat insulation. The width w of the gap 8 at the axial center of the recess 7 is preferably 0.03 mm or more. As a result, the space occupied by the gap 8 is increased, so that the heat insulation is further improved. More preferably, the width w is half or less than the depth of the recess 7 . When the width w is 1/2 or less of the depth of the concave portion 7, the end portion of the columnar body 6 inserted into the concave portion 7 is fitted and fixed so that it can withstand vibration and pull-out force sufficiently. can.
On the other hand, the rear end portion of the columnar body 6 is bonded to the inner surface of the lid 3 via the second bonding layer 9 .

In the present disclosure, at least the tip portion of the columnar body 6 is made of a first ceramic containing aluminum oxide as a main component. Further, the substrate 2 is made of a second ceramic containing aluminum oxide as a main component.
Both the first ceramics and the second ceramics should have a thermal conductivity of 33 W/(m·K) or less, preferably 32 W/(m·K) or less at 20°C. As described above, since both the tips of the columnar bodies 6 and the base 2 are made of ceramics having a low thermal conductivity, heat insulation is ensured.
The thermal conductivity can be determined according to JIS R 1611:2010.

The first ceramics forming the tip of the columnar body 6 preferably has a higher content of aluminum oxide than the second ceramics of the base 2 . As a result, the glass component (sintering aid) contained in the first ceramics is less than the glass component (sintering aid) contained in the second ceramics. Mechanical properties such as rigidity are enhanced. On the other hand, from the inner peripheral surface of the concave portion 7 facing the outer peripheral surface of the tip portion of the columnar body 6, the glass component is easily eluted by firing, which will be described later. It is possible to prevent the gap 8 from being closed even if an external pressure is applied from the opening.
Here, the content of aluminum oxide contained in the second ceramics is 95% by mass or more, preferably 96% by mass or more and 99% by mass or less.

The first ceramics and the second ceramics may contain aluminum oxide as a main component and contain silicon, magnesium and calcium. Specifically, silicon may be contained in an amount of 0.01% by mass or more and 1% by mass or less in terms of oxide. Magnesium may be contained in an amount of 0.1% by mass or more and 0.4% by mass or less in terms of oxide. Calcium may be contained in an amount of 0.01% by mass or more and 1% by mass or less in terms of oxide.
The total content of silicon, magnesium, and calcium elements converted to oxides is preferably lower in the first ceramics than in the second ceramics. As a result, the high-temperature creep property of the first ceramics is enhanced, so that even if the tip portion of the columnar body 6 is lengthened, it can be used in a high-temperature environment for a long period of time. In particular, the difference in the total content of the elements converted to oxides is preferably 0.6% by mass or more and 1% by mass or less.

The total amount of oxides of silicon, magnesium and calcium contained in the second ceramics is preferably 1% by mass or less. Thereby, the rigidity of the substrate 2 made of the first ceramics and the second ceramics can be increased.
Here, the total content of the above elements converted to oxides in the first ceramics is, for example, 0.17% by mass or more and 0.57% by mass or less.
The main component in the first ceramics and the second ceramics refers to a component that accounts for 90% by mass or more of 100% by mass of the components that constitute the respective ceramics. You just have to identify. The content of the identified component may be obtained by using an ICP (Inductively Coupled Plasma) emission spectrometer or a fluorescent X-ray spectrometer (XRF) to determine the content of the element and convert it to the identified component. .

It is preferable that the average value of the equivalent circle diameter of the aluminum oxide crystal grains of the first ceramics is smaller than that of the second ceramics. As a result, the mechanical properties such as the three-point bending strength and rigidity of the tip portion are enhanced, so that the tip portion and the later-described convex portion can be lengthened. The equivalent circle diameter may be obtained according to the following procedure.
First, each cross-section of the base 2 and the tip of the columnar body 6 is polished to a mirror surface.
Specifically, the following first polishing to third polishing are sequentially performed.
(1) First polishing: Polishing with a diamond disk using diamond abrasive grains with an average grain size _D50 of 45 μm (2) Second polishing: Polishing with a copper plate using diamond grains with an average grain size _D50 of 3 μm ( 3) Third polishing: Polishing with a tin plate using diamond abrasive grains with an average particle diameter _D50 of 0.5 μm The surface obtained by heat-treating the polished surface obtained by the above-described method at 1350 ° C. is viewed with a digital macroscope. (VHX-500) and obtained by photographing at a magnification of 400 times. Specifically, a range having an area of 7.2×10 ⁻³ mm ² in the photographed image is taken as the measurement range. Equivalent circle diameters of aluminum oxide crystal grains can be obtained by analyzing the measurement range using image analysis software (eg, Win ROOF manufactured by Mitani Shoji Co., Ltd.). In the analysis, the threshold value of the equivalent circle diameter is set to 0.2 μm, and equivalent circle diameters of 0.2 μm or less are not included in the calculation of the average value.

Both the average values of the equivalent circle diameters of the first ceramics and the second ceramics obtained by this measurement method are the average values of the equivalent circle diameters of translucent alumina (for example, LUCALOX, a trademark of General Electric Co., Ltd.) (31. 6 μm to 53.6 μm). For example, the average equivalent circle diameter of the first ceramics is 3 μm or more and 8 μm or less, and the average value of the equivalent circle diameters of the first ceramics is 10 μm or more and 30 μm or less. Both the first ceramics and the second ceramics do not transmit visible light and have a relative density of 96% or more. The relative density of the first ceramics is the percentage of the apparent density to the theoretical density of the first ceramics, and the apparent density is determined according to JIS R 1634:1998. The relative density of the second ceramic can also be obtained in the same way.

Next, a method for manufacturing the heat insulator 1 will be described.
First, the process of manufacturing the substrate 2 will be described. Aluminum oxide powder (with a purity of 99.9% by mass or more), which is the main component of the second ceramics, and powders of silicon oxide, magnesium hydroxide, and calcium carbonate are put into a grinding mill together with a solvent (ion-exchanged water). Then, an organic binder and a _dispersant for dispersing the aluminum oxide powder are added and mixed to obtain a slurry.

Here, the content of silicon oxide powder is 0.01 to 0.05% by mass, the content of magnesium hydroxide powder is 0.15 to 0.57% by mass, and the content of calcium carbonate powder is The content is 0.9 to 1.8% by mass, and the balance is aluminum oxide powder and unavoidable impurities.

Organic binders include acrylic emulsion, polyvinyl alcohol, polyethylene glycol, polyethylene oxide and the like.

Next, after the slurry is spray granulated to obtain granules, the granules are filled into a mold. Using a uniaxial press molding device or a cold isostatic pressing device, the granules filled in the mold are pressed at a molding pressure of 78 MPa or more and 128 MPa or less to obtain a rectangular plate-shaped molded body. Then, by cutting, a depression that will become the concave portion 7 after firing and an enclosing space that will become the internal space 5 after the lid 3 is joined are formed in the compact 1 . The enclosed space is a space which is open on one side in the thickness direction of the molded body and whose outer edge is surrounded. A carbon sheet (not shown) is laid on the inner bottom surface of the recess. The thickness of the carbon sheet may be the same as the width w of the gap 8 to be formed. Considering the degreasing property, the carbon sheet is preferably porous, and particularly preferably has a porosity of 30% or more and 80% or less.

On the other hand, the molded body of the columnar body 6 is obtained in the same manner as the base body 2 . At this time, the content of the silicon oxide powder is 0.3 to 1% by mass, and the content of the magnesium hydroxide powder is 0.15 to 0.57, based on the total 100% by mass of the raw material powders constituting the compact of the columnar body 6. % by weight, the content of calcium carbonate powder is 0.018 to 0.9% by weight, and the balance is aluminum oxide powder and unavoidable impurities.

The molded body of the produced columnar body 6 is fired to obtain a sintered body. The firing atmosphere is an air atmosphere, a reduced pressure atmosphere, or a vacuum atmosphere, the firing temperature is preferably 1500° C. or higher and 1700° C. or lower, and the holding time is preferably 4 hours or longer and 6 hours or shorter. With the leading end of the sintered columnar body 6 inserted into the recess, the rectangular plate-shaped body is fired under the same firing conditions as those described above. As a result, the tip of the columnar body 6 is fitted into the recess 7 by firing shrinkage, the carbon sheet disappears, and a gap 8 is formed between the tip surface of the columnar body 6 and the inner bottom surface of the recess 7. be.

Next, the lid 3 is attached. If the lid 3 is made of ceramics (for example, ceramics containing aluminum oxide as the main component similar to the substrate 2), the other end face of the columnar body 6 and the peripheral edge of the substrate 2 are positioned. A glass paste is applied to each of the end surfaces of the rising portions 21, and glass bonding is performed to obtain the heat insulator 1. FIG.

On the other hand, when the cover 3 is made of metal (for example, stainless steel such as SUS304 and SUS630, aluminum, etc.), brazing material (for example, 63 to 70.5% by mass of Ag--27.5 to 35% by mass of Cu--2% by mass of Ti) are applied and brazed to obtain a heat insulator 1.

Next, a fitted body according to another embodiment of the present disclosure will be described with reference to FIG. In addition, the same code|symbol is attached|subjected to the same structural member as the fitting body shown in FIG. 3, and description is abbreviate|omitted.
This embodiment comprises a first member 11 having a convex portion 11b and a base portion 11a supporting the convex portion 11b, and a second member 12 having a concave portion 17 into which the convex portion 11b is inserted. The protrusion 11 b is fitted into the recess 17 and has a gap 8 between the tip surface of the protrusion 11 b and the inner bottom surface of the recess 17 .

In the first member 11, at least the projections 11b are made of the first ceramics containing aluminum oxide as a main component, similarly to the columnar body 6 described above. The second member 12 is made of a second ceramic containing aluminum oxide as a main component, like the substrate 2 described above.
The convex portion 11b can be formed by cutting, for example.

The heat insulator 1 manufactured using the fitted body shown in FIG. 3 or 4 can be used, for example, in semiconductor manufacturing equipment, plasma equipment, etc., but is not limited to these uses. Moreover, the fitted body shown in FIG. 3 or 4 can be used not only for the heat insulating body 1 but also for various uses that require fitting.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the present disclosure.

REFERENCE SIGNS LIST 1 heat insulator 2 base 21 rising portion 3 lid 4 first bonding layer 5 internal space 7 recess 8 gap 9 second bonding layer 11 first member 11a base 11b projection 12 second member 17 recess

An object of the present disclosure is to provide a fitting having high heat insulation and a connection mechanism having this fitting.

Claims (9)

a columnar body, at least the tip portion of which is made of a first ceramic containing aluminum oxide as a main component;
a base made of a second ceramic containing aluminum oxide as a main component, having a recess into which the tip is inserted;
The fitting body, wherein the tip portion is fitted in the recess, and a gap is provided between a tip surface of the tip portion and an inner bottom surface of the recess. a first member having a projection made of a first ceramic containing aluminum oxide as a main component and a base supporting the projection;
a second member made of a second ceramic containing aluminum oxide as a main component and having a recess into which the protrusion is inserted;
The fitting body, wherein the projection is fitted into the recess, and a gap is provided between the tip surface of the projection and the inner bottom surface of the recess. 3. The fitted body according to claim 1, wherein the width of said gap at the axial center of said recess is 0.03 mm or more. The fitted body according to any one of claims 1 to 3, wherein said first ceramics has a higher content of aluminum oxide than said second ceramics. 5. The fitted body according to claim 4, wherein a content of aluminum oxide contained in said second ceramics is 95% by mass or more. Said first ceramics and said second ceramics contain silicon, magnesium and calcium, and the total content of these elements in terms of oxides is lower in the first ceramics than in the second ceramics. 6. The fitting body according to any one of 5. 7. The fitted body according to claim 6, wherein the total content of silicon, magnesium, and calcium in said second ceramics in terms of oxides is 1% by mass or less. The fitted body according to any one of claims 1 to 7, wherein said first ceramic has a smaller average equivalent circle diameter of aluminum oxide crystal grains than said second ceramic. A connection mechanism comprising the fitted body according to any one of claims 1 to 8.

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