JP4025576B2 - Bottomed cylindrical body, manufacturing method thereof, and sensor - Google Patents

Description

【００４８】
表１の結果から、筒状セラミック成形体と封止用セラミック成形体のＡｌ₂Ｏ₃含有量差が本発明の範囲を逸脱する試料Ｎｏ．１〜３、Ｎｏ．７は、熱サイクル試験後に剥離、あるいはクラックが発生した試料が多かった。
【００４９】
これらの比較例に対して、本発明の試料では、熱サイクル試験後に隙間が見られる試料の発生割合は１０％以下に抑えられ、且つ熱サイクル試験後のクラック発生割合も５％以下となり、空燃比センサとして用いても高い信頼性を有することが判る。
【００５０】
【発明の効果】
以上詳述したとおり、本発明の有底筒状体は、封止体中のＡｌ₂Ｏ₃含有量を筒状体中のＡｌ₂Ｏ₃含有量よりも多くしたので、筒状体と封止体の焼成時の収縮を制御し、封止体の焼結完了後に筒状体を焼結させ、筒状体と封止体との高い接合強度を長期間維持することができる。これにより、かかる有底筒状体を、例えば自動車等の内燃機関における排出ガス中の酸素濃度を検出する空燃比センサとして使用すると、急速昇温などによる耐熱衝撃性を向上できる。
【図面の簡単な説明】
【図１】本発明の有底筒状体を示すもので、（ａ）は斜視図、（ｂ）は断面図である。
【図２】本発明の有底筒状体の製法を説明するための工程図である。
【図３】本発明の空燃比センサを示すもので、（ａ）は斜視図、（ｂ）は（ａ）のＸ₁−Ｘ₁断面図である。
【符号の説明】
１・・・筒状体
３・・・封止体
１１・・・筒状セラミック成形体
１６・・・基準電極
１７・・・測定電極[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bottomed cylindrical body, a method of manufacturing the same, and a sensor, and more particularly, a bottomed cylindrical body integrated by simultaneously firing a cylindrical body made of a solid electrolyte ceramic having oxygen ion conductivity and a sealing body. And its manufacturing method and sensor.
[0002]
[Prior art]
Conventionally, as a method for sealing one end of a cylindrical body, for example, as disclosed in JP-A-5-84732, an organic porous body such as a filter paper is fixed in the cylindrical body, and a ceramic slurry is stored in the cylindrical body. There is known a method of depositing on a porous organic material by pouring and discharging the porous organic material during firing.
[0003]
[Problems to be solved by the invention]
However, in the sealing method as described above, even when the ceramic slurry constituting the cylindrical body and the sealing body are the same or different, the firing shrinkage rate was almost the same. There has been a problem in that the bonding strength with the sealing body filled inside is low. Thereby, the interface of a cylindrical body and a sealing body deteriorated with time, and there existed a problem that a clearance gap and a crack were easy to generate | occur | produce.
[0004]
When such a bottomed cylindrical body is used as a sensor (air-fuel ratio sensor) for detecting the oxygen concentration in exhaust gas in an internal combustion engine such as an automobile, the cylindrical body and the sealed body are sealed by a thermal shock due to rapid temperature rise or the like. There has been a problem that the interface of the stationary body deteriorates with time, gaps and cracks are generated at the joint interface, the sensor is destroyed, or the sensor characteristics are adversely affected.
[0005]
An object of the present invention is to provide a bottomed cylindrical body, a method for manufacturing the same, and a sensor that can easily improve the bonding strength between the cylindrical body and the sealing body.
[0006]
[Means for Solving the Problems]
The bottomed cylindrical body of the present invention is provided with a ceramic sealing body inside one end of a ceramic cylindrical body, and seals one end of the cylindrical body. The sealing body contains ZrO ₂ as main crystal particles, and is a bottomed cylindrical body in which the cylindrical body and the sealing body are fired simultaneously, and the cylindrical body and the sealing body are either also contain Al ₂ O _3, and Al ₂ O ₃ content in the sealing member, characterized in that more than Al ₂ O ₃ content of the tubular body in.
[0007]
Such a bottomed cylindrical body is provided with a sealing ceramic molded body inside one end portion of the cylindrical ceramic molded body, and after sealing one end portion of the cylindrical ceramic molded body, the cylindrical ceramic molded body A method of manufacturing a bottomed cylindrical body in which a molded body and the sealing ceramic molded body are simultaneously fired, wherein the cylindrical ceramic molded body and the sealing ceramic molded body have ZrO ₂ as a main crystal powder. , obtained by using the containing Al ₂ O _3, and has a content of Al ₂ O ₃ of the sealing ceramic molded body for locking and more than the content of Al ₂ O ₃ in the tubular ceramic molded body production method be able to.
[0008]
According to such a manufacturing method, the cylindrical ceramic molded body and the sealing ceramic molded body contain ZrO ₂ as the main crystal powder, and the cylinder is more than the Al ₂ O ₃ content of the sealing ceramic molded body. Since the Al ₂ O ₃ content of the shaped ceramic molded body is increased, the sintering temperature T1 of the sealing ceramic molded body containing a large amount of Al ₂ O ₃ as a sintering aid for promoting grain growth during firing is increased. When the cylindrical ceramic molded body and the sealing ceramic molded body are fired at the same time, the shrinkage of the sealed body ends earlier than the shrinkage of the tubular body. The cylindrical body is sintered in a state where the sealing body is strongly clamped, and the sealing body is firmly bonded to the inside of the cylindrical body, so that deterioration with time can be prevented and strong bonding can be maintained for a long time.
[0009]
Moreover, in the manufacturing method of the bottomed cylindrical body of the present invention, the Al ₂ O ₃ content relative to 100 mol parts of the main crystal powder in the cylindrical ceramic molded body is m (mol parts), and the sealing ceramic molded body contains When the Al ₂ O ₃ content with respect to 100 mol parts of the main crystal powder is n (mol parts), 0.3 ≦ (nm) is satisfied. In such a manufacturing method of the bottomed cylindrical body, the sintering temperature T1 of the sealing ceramic molded body is surely lower than the sintering temperature T2 of the cylindrical ceramic molded body, and the cylindrical body is sealed with the sealing body. Sintering can be performed in a tighter state, and strong bonding can be maintained for a long time.
[0010]
Furthermore, in the manufacturing method of the bottomed cylindrical body of the present invention, the sintering temperature T1 of the sealing ceramic molded body is lower than the sintering temperature T2 of the cylindrical ceramic molded body and is sintered at the sintering temperature T1 or higher. Temporarily holding at a temperature lower than the sintering temperature T2 to sinter the ceramic molded body for sealing, and then keeping at a temperature higher than the sintering temperature T2 to sinter the cylindrical ceramic molded body. Features.
[0011]
According to such a manufacturing method, after the sintering of the sealing body is completed at a temperature higher than the sintering temperature T1 and lower than the sintering temperature T2, it is higher than the sintering temperature T1 of the sealing body, and By firing at a temperature higher than the sintering temperature T2, the cylindrical body is more efficiently tightened with respect to the sealing body, and a sintered body with no gap between the joining surfaces can be obtained.
[0012]
Further, in the method for producing a bottomed cylindrical body of the present invention, the cylindrical ceramic molded body and the sealing ceramic molded body contain a rare earth element oxide, and the rare earth element oxide content in the cylindrical ceramic molded body x is 4-7 mol%, the rare earth element oxide content y in the sealing ceramic molded body is 4.4-8 mol%, and satisfies 0.4 ≦ (y−x). Is desirable.
[0013]
Thereby, for example, as a result of providing a difference in the content of rare earth element oxide (RE ₂ O ₃ : RE is a rare earth element) in the sealed body and the cylindrical body mainly composed of ZrO ₂ often used as a solid electrolyte, Mutual diffusion of Zr and RE across the interface between the cylindrical body and the sealing body is promoted, the bonding force between ZrO ₂ of the cylindrical body and the sealing body is enhanced, and the sealing body is firmly Bonded to the inner surface, the bonding strength between the cylindrical body and the sealing body can be improved.
[0014]
In the method for producing a bottomed cylindrical body of the present invention, sealing of one end portion of the cylindrical ceramic molded body by the sealing ceramic molded body is performed in the cylindrical ceramic molded body in the slurry forming the sealing ceramic molded body. After dipping one end of the body, it is lifted and dried, or after sealing one end of the cylindrical ceramic molded body with a sealing member, a slurry forming the sealing ceramic molded body is formed. It is desirable to drop it into the cylindrical ceramic molded body and dry it.
[0015]
According to such a manufacturing method, the ceramic slurry constituting the sealing ceramic molded body can be easily supplied into the cylindrical ceramic molded body, and the sealing ceramic molded body is placed inside one end of the cylindrical ceramic molded body. It can be easily formed, and mass production can be expected.
[0016]
The sensor according to the present invention is provided with a sensing part formed by forming electrodes on the inner and outer surfaces of the bottomed cylindrical body opposite to each other in the bottomed cylindrical body according to claim 1 made of solid electrolyte ceramics. In such a sensor, for example, a sensor (air-fuel ratio sensor) that detects the oxygen concentration in exhaust gas in an internal combustion engine such as an automobile by utilizing the oxygen ion conductivity of solid electrolyte ceramics. ), The cylindrical body and the sealing body can be firmly bonded, and high bonding strength can be maintained for a long time. For example, by using it as an air-fuel ratio sensor, Can sufficiently withstand, and the sensor life can be greatly improved.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the bottomed cylindrical body of the present invention is provided with a ceramic sealing body 3 inside one end portion of the ceramic cylindrical body 1, whereby the one end portion of the cylindrical body 1 is sealed. It has been stopped. The main crystal particles of the cylindrical body 1 and the sealing body 3 are ZrO ₂ , and the cylindrical body 1 and the sealing body 3 are simultaneously fired and integrated.
[0018]
Then, the bottomed cylindrical body of the present invention, the tubular body 1, the sealing body 3 is contained Al ₂ O _3, the Al ₂ O ₃ content of the tube in 1 m (mol parts) When the Al ₂ O ₃ content in the sealing body ₃ is n (mole part), n> m is satisfied. This is because the tightening force by the cylindrical body 1 is low when n ≦ m. In particular, it is desirable to satisfy 0.3 ≦ (nm) from the viewpoint of improving the tightening force due to the contraction of the cylindrical body 1 and suppressing the generation of gaps at the joint interface, and more preferably 0.5 ≦ It is desirable that (nm).
[0019]
The bottomed cylindrical body is made of a solid electrolyte having oxygen ion conductivity, and is made of ZrO ₂ in which a rare earth element oxide is dissolved.
[0020]
Therefore, the main crystal particles of the cylindrical body 1 and the sealing body 3 are ZrO ₂ particles in which the rare earth element oxide is dissolved. This makes it possible to use the oxygen ion conductivity as a sensor for detecting the oxygen concentration in exhaust gas in an internal combustion engine such as an automobile. Examples of rare earth elements include Y, Yb, and Ce.
[0021]
As shown in FIG. 2, the bottomed cylindrical body configured as described above forms a sealing ceramic molded body inside one end portion of the cylindrical ceramic molded body 11, thereby forming the cylindrical ceramic molded body 11. After sealing one end of the cylindrical ceramic molded body 11, the cylindrical ceramic molded body 11 and the sealing ceramic molded body are simultaneously fired.
[0022]
Specifically, first, in order to form the cylindrical ceramic molded body 11 and the sealing ceramic molded body, a ZrO ₂ powder in which a rare earth element oxide is dissolved and an Al ₂ O ₃ powder are prepared.
[0023]
That is, the cylindrical ceramic molded body 11 is sealed with a slurry formed by adding an organic solvent to a mixed powder of ZrO ₂ powder and Al ₂ O ₃ powder in which a rare earth element oxide is dissolved, and mixing them. A ceramic molded body is produced.
[0024]
The cylindrical ceramic molded body 11 is formed by extrusion molding, and the sealing ceramic molded body is formed by a slurry dipping method or a slurry dropping method.
[0025]
The formation of the sealing ceramic molded body by the slurry dip method is performed by first immersing one end portion of the cylindrical ceramic molded body 11 in the slurry accommodated in the container 9 for a certain period of time, lifting it and drying it. A ceramic molded body for sealing is filled and formed inside one end of the shaped ceramic molded body 11.
[0026]
Moreover, in the slurry dropping method, after sealing the lower end of the cylindrical ceramic molded body 11 with, for example, a carbon sealing member 10, the above-described slurry is dropped from the opening at the upper end of the cylindrical ceramic molded body 11. Then, after drying, the sealing member 10 is removed, and a sealing ceramic molded body is formed at the lower end of the cylindrical ceramic molded body 11.
[0027]
By using these slurry dipping methods and slurry dropping methods, the ceramic slurry constituting the sealing body can be easily enclosed in the cylindrical ceramic molded body 11, and mass productivity can also be expected. Furthermore, simultaneous firing eliminates the need for repeated exposure to a high-temperature atmosphere, can reduce the cause of deterioration of the properties of the sintered body, and can further reduce costs by shortening the process.
[0028]
In this way, the cylindrical ceramic body 11 is filled with the sealing ceramic body and fired at a predetermined temperature to produce the bottomed tubular body of the present invention.
[0029]
In the manufacturing method of the bottomed cylindrical body of the present invention, in particular, ZrO ₂ is used as the main crystal powder of the cylindrical ceramic molded body 11 and the sealing ceramic molded body, and the cylindrical ceramic molded body 11 and the sealing ceramic molded body are used. All the bodies contain Al ₂ O ₃ , and the Al ₂ O ₃ content in the ceramic molded body for sealing needs to be larger than the Al ₂ O ₃ content in the cylindrical ceramic molded body 11. .
[0030]
Thus, the content of Al ₂ O ₃ ceramic molded body for sealing, by more than the content of Al ₂ O ₃ cylindrical ceramic molded body 11, sintering to promote the grain growth during firing The sintering temperature T1 of the sealing ceramic molded body containing a large amount of the auxiliary agent Al ₂ O ₃ can be made lower than the sintering temperature T2 of the cylindrical ceramic molded body 11, whereby the cylindrical body 1 is sealed. It can join in the state which fastened the stop body 3, and can obtain strong joint strength.
[0031]
In particular, the content of Al ₂ O _{3 with} respect to 100 mole parts of the main crystal powder in the cylindrical ceramic molded body 11 is m (mol%), and the content of Al ₂ O _{3 is with} respect to 100 mole parts of the main crystal powder in the ceramic molded body for sealing. By satisfying 0.3 ≦ (nm) when the amount is n (mol%), the cylindrical body 1 can be joined with the sealing body 3 tightened more strongly, and the joint strength is stronger. Can be obtained.
[0032]
Further, in the present invention, the cylindrical ceramic molded body 11 and the sealing ceramic molded body contain a rare earth element, and the content x of the rare earth element oxide in the cylindrical ceramic molded body 11 is 4 to 7 mol%. It is desirable that the content y of the rare earth element oxide in the ceramic molded body for stopping is 4.4 to 8 mol% and that 0.4 ≦ (y−x) is satisfied.
[0033]
By having such a composition, the mutual diffusion of Zr and RE across the interface between the cylindrical body and the sealing body is promoted, the bonding force between ZrO _{2 of the} cylindrical body and the sealing body is enhanced, and the sealing is performed. The stationary body is firmly bonded to the inner surface of the cylindrical body, and the bonding strength between the cylindrical body and the sealing body can be improved. In particular, 5 ≦ x ≦ 6, 6 ≦ y ≦ 7, and 1 ≦ (y−x) ≦ 2 from the viewpoint of further promoting the mutual diffusion of Zr and RE across the interface between the cylindrical body and the sealing body. It is desirable to be.
[0034]
Furthermore, in the manufacturing method of the bottomed cylindrical body of the present invention, the sintering temperature T1 of the sealing ceramic molded body is lower than the sintering temperature T2 of the cylindrical ceramic molded body 11 and is equal to or higher than the sintering temperature T1. Temporarily keeping at a temperature lower than the sintering temperature T2 to sinter the ceramic molded body for sealing, and then keeping at a temperature higher than the sintering temperature T2 to sinter the cylindrical ceramic molded body 11. desirable.
[0035]
By temporarily keeping the sintering body at a temperature higher than the sintering temperature T1 and lower than the sintering temperature T2, the sealing body is completely sintered, and by keeping at a temperature higher than the sintering temperature T2, the cylindrical body By proceeding with the sintering, the cylindrical body is more efficiently tightened with respect to the sealing body, and a sintered body having no gap between the joining surfaces can be obtained.
[0036]
The sensor of the present invention has a sensing part formed by forming electrodes on the inner and outer surfaces facing each other of the bottomed cylindrical body made of the solid electrolyte ceramic as described above. As an example, FIG. 1 shows a fuel ratio sensor. For example, as shown in the perspective view of FIG. 3A and the X ₁ -X ₁ cross-sectional view of FIG. 3B, the air-fuel ratio sensor has an inner surface of a cylindrical body 15 whose tip is sealed with a sealing body. A reference electrode 16 and a measurement electrode 17 made of a platinum electrode in which ZrO ₂ particles are dispersed are respectively deposited on the outer surface.
[0037]
Around the measurement electrode 17 formed on the outer surface of the cylindrical body 15 whose tip is sealed, there is Al ₂ O ₃ , a composite oxide of Al ₂ O ₃ and MgO, or Al ₂ O ₃ and Y ₂ O _3. A ceramic insulating layer 18 made of a complex oxide such as 2 to 50 μm in thickness is deposited. A predetermined opening 19 is formed in the ceramic insulating layer 18 so that part or all of the measurement electrode 17 is exposed. Platinum or the like is formed in the ceramic insulating layer 18 around the opening 19. A heating element 20 made of is embedded.
[0038]
In addition, the heating element 20 is connected to the terminal electrode 22 via the lead electrode 21, and by applying a current to the heating element 20 through the lead electrode 21, the heating element 20 is heated, and the measurement electrode 17, cylindrical shape is applied. The sensing unit composed of the body 15 and the reference electrode 16 is configured to be rapidly heated to a predetermined temperature. Further, a ceramic heat insulating layer 23 is formed on the surface of the ceramic insulating layer 18 in order to prevent heat from being emitted from the heating element 20.
[0039]
In order to prevent the electrode from being poisoned on the surface of the measurement electrode 17, a porous ceramic made of ZrO ₂ (containing a rare earth element oxide such as Y ₂ O ₃ ), Al ₂ O ₃ , MgAl ₂ O ₄ or the like. A protective layer 24 is formed. Alternatively, ZrO ₂ (containing a rare earth element oxide such as Y ₂ O ₃ ), Al ₂ O ₃ , MgAl ₂ O ₄ , MgO, or γ-Al ₂ O ₃ having fine pores on the surface of the measurement electrode 17 is used. The used gas diffusion control layer may be formed.
[0040]
In the sensor as described above, the bottomed cylindrical body of the present invention is used as a sensor (air-fuel ratio sensor) for detecting the oxygen concentration in exhaust gas in an internal combustion engine such as an automobile, so that thermal shock due to rapid temperature rise or the like. Can be sufficiently tolerated, and the reliability of long-time operation can be improved.
[0041]
【Example】
A commercially available Al ₂ O ₃ powder having an average particle diameter of 0.3 μm, a ZrO ₂ powder containing 4.1 to 6.2 mol% Y ₂ O ₃ prepared as a main crystal powder by a coprecipitation method, ZrO ₂ powders containing 5 to 7.2 mol% Y ₂ O ₃ were prepared as main crystal powders prepared by the precipitation method.
[0042]
Next, to the ZrO ₂ powder containing 4.1 to 6.2 mol% Y ₂ O ₃ , the Al ₂ O ₃ powder in the ratio shown in Table 1 is added to and mixed with 100 mol parts of the ZrO ₂ powder. After that, a polyvinyl alcohol solution as an organic binder and pure water as a solvent were added to prepare clay, and a cylindrical ceramic molded body having an outer diameter of 5 mm and an inner diameter of 3 mm was prepared by extrusion molding.
[0043]
On the other hand, 5 to 7.2 mol% Y ₂ O ₃ ZrO ₂ powder containing, with respect to the ZrO ₂ powder to 100 parts by mol, was added and mixed with Al ₂ O ₃ powder in the proportions shown in Table 1, Mineralol was added as a predetermined amount of solvent to prepare a slurry for a ceramic molded body for sealing.
[0044]
Then, the cylindrical ceramic molded object was immersed in the said slurry, and it lifted and dried, and produced the molded object which sealed the inside of the one end part of the cylindrical ceramic molded object with the ceramic molded object for sealing.
[0045]
Thereafter, this molded body was kept in the atmosphere at 1400 ° C. for 1 hour and at 1550 ° C. for 1 hour, and integrally fired in a two-step pattern to produce a bottomed cylindrical body. In addition, sintering temperature T1 of the said ceramic molded object for sealing was 1350-1400 degreeC, and sintering temperature T2 of the said cylindrical ceramic molded object was 1500-1550 degreeC.
[0046]
The obtained 20 bottomed cylindrical bodies were heated up to 700 ° C. in 30 seconds from room temperature and then air-cooled to room temperature as one cycle, and this was performed 100,000 times (thermal cycle test). Thereafter, the ratio of the sample in which a crack occurred at the joint between the cylindrical body and the sealing body is shown in Table 1 as the crack ratio. In addition, about the sample joined on the same conditions, the presence or absence state of the clearance gap between a cylindrical body and a sealing body is confirmed with a metal microscope (150 times) by cut | disconnecting a cross section after a thermal cycle test. It was. These results are shown in Table 1.
[0047]
[Table 1]

[0048]
From the results in Table 1, the sample No. _{2 in} which the difference in Al ₂ O ₃ content between the cylindrical ceramic molded body and the sealing ceramic molded body deviates from the scope of the present invention. 1-3, no. No. 7 had many samples where peeling or cracking occurred after the thermal cycle test.
[0049]
In contrast to these comparative examples, in the sample of the present invention, the generation rate of the sample in which gaps are observed after the thermal cycle test is suppressed to 10% or less, and the crack generation rate after the thermal cycle test is also 5% or less. It can be seen that it has high reliability even when used as a fuel ratio sensor.
[0050]
【The invention's effect】
As described in detail above, since the bottomed cylindrical body of the present invention was more than the content of Al ₂ O ₃ the tubular body in the content of Al ₂ O ₃ in the sealing body, the tubular body and sealing The shrinkage at the time of firing the stationary body can be controlled, and the cylindrical body can be sintered after the sealing body has been sintered, and the high bonding strength between the cylindrical body and the sealed body can be maintained for a long time. Thus, when such a bottomed cylindrical body is used as an air-fuel ratio sensor for detecting the oxygen concentration in exhaust gas in an internal combustion engine such as an automobile, the thermal shock resistance due to rapid temperature rise or the like can be improved.
[Brief description of the drawings]
FIG. 1 shows a bottomed cylindrical body of the present invention, in which (a) is a perspective view and (b) is a cross-sectional view.
FIG. 2 is a process diagram for explaining a method for producing a bottomed cylindrical body according to the present invention.
3A and 3B show an air-fuel ratio sensor of the present invention, in which FIG. 3A is a perspective view, and FIG. 3B is a cross-sectional view taken along line X ₁ -X _{1 in} FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cylindrical body 3 ... Sealing body 11 ... Cylindrical ceramic molded body 16 ... Reference electrode 17 ... Measurement electrode

Claims (5)

A ceramic sealing body is provided inside one end portion of the ceramic cylindrical body, and one end portion of the cylindrical body is sealed, and the cylindrical body and the sealing body are formed of ZrO ₂ as a main crystal. A bottomed cylindrical body in which the cylindrical body and the sealing body are fired at the same time, the cylindrical body and the sealing body both contain Al ₂ O ₃ , and A bottomed cylindrical body characterized in that the Al ₂ O ₃ content in the sealing body is larger than the Al ₂ O ₃ content in the cylindrical body. After providing a sealing ceramic molded body inside one end of the cylindrical ceramic molded body and sealing one end of the cylindrical ceramic molded body, the cylindrical ceramic molded body and the sealing ceramic molded body The cylindrical ceramic body and the sealing ceramic body contain ZrO ₂ as the main crystal powder, and contain Al ₂ O ₃ , and A process for producing a bottomed cylindrical body, wherein the content of Al ₂ O ₃ in the ceramic molded body for sealing is greater than the content of Al ₂ O ₃ in the cylindrical ceramic molded body. The Al ₂ O ₃ content relative to 100 mol parts of the main crystal powder in the cylindrical ceramic molded body is m (mol parts), and the Al ₂ O ₃ content relative to 100 mol parts of the main crystal powder in the sealing ceramic molded body is 3. The method for producing a bottomed cylindrical body according to claim 2, wherein when n (mole part) is satisfied, 0.3 ≦ (nm) is satisfied. Sintering temperature T1 of the ceramic molded body for sealing is temporarily kept at a temperature lower than sintering temperature T2 that is lower than sintering temperature T2 of cylindrical ceramic molded body, and is lower than sintering temperature T2. The bottomed cylindrical shape according to claim 2 or 3, wherein the ceramic molded body for fixing is sintered and then kept at a temperature higher than a sintering temperature T2 to sinter the cylindrical ceramic molded body. Body making method. The bottomed cylindrical body made of solid electrolyte ceramics is provided with a sensing portion formed by forming electrodes on the inner and outer surfaces of the bottomed cylindrical body facing each other. Sensor.

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