JP2003214811A - Method for measuring high-temperature elongation and measuring sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for measuring a high-temperature elongation capable of easily carrying out a measurement of the high-temperature elongation for a constituting member or the like of an apparatus used at a high temperature, and to provide a measuring sensor. <P>SOLUTION: The method for measuring the high-temperature elongation comprises the steps of fixing a thin film 2 made of ceramics having a known elongation at breakage to a surface of a member 44 to be measured, and examining the presence or absence of a breakage of the film 2 after the high- temperature elongation occurs. Thus, the elongation of the member 44 to be measured is known. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature elongation measuring method and a measuring sensor suitable for measuring high temperature elongation such as creep elongation occurring in members used under high temperature conditions. Is.

[0002]

2. Description of the Related Art Regarding equipment used under high temperature conditions,
In order to prevent or predict breakage of the constituent member, it is important to measure the elongation (high temperature elongation) of the member under high temperature conditions.

As a conventional method for measuring the elongation of a member, firstly, a strain gauge is attached to a member to be measured and the elongation of the member is measured as a change in electric resistance. Secondly, there is a method of measuring the deformation by directly or indirectly observing the deformation state of the crystal grains of the member to be measured with a microscope and performing image analysis.
As a third method, there is a method using a wire type stress measuring sensor disclosed in Japanese Patent Laid-Open No. 9-5175. As shown in FIG. 11, the stress measurement sensor 101 used in the method is one in which both ends of a metal wire 102 having a known breaking strain are fixed on a thin film 104 via a fixing base 103. This is the member to be measured (not shown)
The stress applied to the member to be measured is known by whether or not the wire 102 is broken after being adhered to the substrate and used at high temperature.

[0004]

In the case of the above-mentioned first method, the material used as the base of the strain gauge is generally one having a heat resistant temperature of up to about 600 ° C. There is a problem that under high temperature conditions of exceeding ° C, the measured values change greatly and high-precision measurement cannot be performed. Moreover, in the case of the second method, an expensive microscope and an image analysis device are required for the measurement, and the analysis takes time. Since the deformation amount is statistically obtained from the deformation state of the crystal grains that originally have various shapes, there is a disadvantage in accuracy. The wire-type stress measurement sensor used in the third method is suitable for a structure used at a temperature of about 300 ° C., but cannot measure accurately under a temperature condition exceeding that. This is because it is difficult to break a metal with a certain amount of elongation (strain) because the ductility of a metal becomes large at a high temperature and the ductility of the metal largely changes depending on the temperature. Also, in the case of a small sensor having practicality, the metal wire is oxidized and corroded in a short time at a high temperature, and it becomes impossible to show a constant elongation at break.

In view of these points, the invention of the claim of the present application is a method for measuring high temperature elongation, which enables easy measurement of high temperature elongation such as creep elongation for components of equipment used at high temperature. And a sensor for measurement.

[0006]

According to a first aspect of the present invention, there is provided a method for measuring a high temperature elongation, wherein a ceramic thin film having a known elongation at break is fixed on a surface of a member to be measured, and after the high temperature elongation occurs, the ceramic thin film is made. The feature is that the elongation of the member to be measured is known by the presence or absence of breakage of the thin film. The ceramic thin film is fixed directly or indirectly to the surface of the measured member, and one or a plurality of ceramic thin films are fixed to one measured member. When a plurality of thin ceramic films are used, thin films having the same breaking elongation may be used, but a plurality of different thin films may be used. This measuring method is particularly preferable for the measurement of creep elongation at a high temperature of 600 ° C. or higher for which there is no other suitable measuring method, but it can be carried out under the condition of 300 ° C. or higher, and brings about a preferable action and effect. Therefore, "high temperature" referred to above (and each claim below) is 3
A temperature of 00 ° C or higher. Needless to say, "high temperature elongation" includes creep elongation. The "elongation" is represented by, for example, a ratio obtained by dividing the length as an increment that has occurred by the length in the original natural state (elongation rate. Strain.%, Etc.). The "elongation at break" refers to the elongation that occurs from the natural state to the time of breaking.

According to the method of this claim, the elongation at break of the ceramic thin film is known in advance, so that when high temperature elongation occurs (that is, when the equipment including the member to be measured is used under high temperature conditions, for example). ), As a result, if the ceramic thin film is broken, it can be known that the high temperature elongation of the member to be measured exceeds the breaking elongation of the ceramic thin film, and thus the high temperature elongation generated in the member to be measured can be easily measured. be able to. If the elongation can be measured, it becomes possible to know the generated stress from the characteristics (elasticity coefficient etc.) of the member to be measured. Further, when a plurality of ceramic thin films having different breaking elongations are used at the same time, the elongation of the member to be measured can be measured more accurately. This is because the elongation of the member to be measured can be specified as being larger than the maximum value of the breaking elongations of the plurality of ceramic thin films that were broken and smaller than the minimum value of the breaking elongations of the ceramic thin films that were not broken. . If the number of ceramic thin films is increased and the crevices between fracture elongations of the respective thin films are made finer, the elongation of the member to be measured can be specified in a narrower range.

Since the high temperature strength of ceramic materials is high, 60
Not only 0 ° C but also temperatures over 1000 ° C (up to 18 ° C)
It can be used stably even at about 00 ° C. Since ductility is small even at high temperatures and the change in elongation at break does not change significantly with temperature, it is possible to break with a predetermined amount of elongation (that is, an inherent amount determined by the material, shape, and dimensions), and the elongation at high temperature Suitable for accurate measurement. Also, unlike metals, ceramic materials do not easily oxidize or corrode even in a high temperature oxidizing atmosphere, so even if the above ceramic thin film is processed into a small size with practicality, it will be damaged in a short time. There is no fear of doing Therefore, according to the method of this claim, the elongation of the member to be measured can be measured with high accuracy even under a high temperature condition of 600 ° C. or higher for which there is no other suitable measuring method.

A ceramic material suitable for use as the above-mentioned ceramic thin film is alumina (Al
₂ O _3), mullite _{(3Al 2 O 3 + 2SiO 2} ), titania (TiO _2), silicon carbide (SiC), silicon nitride (Si ₃ N _4), zirconia (ZrO _2), such as cermet and the like. Since there are various materials having different coefficients of linear expansion and elongation at break, it is advisable to select the material appropriately according to the usage conditions of the equipment including the member to be measured.

In the measuring method according to the second aspect, in particular, both end portions of the ceramic thin film are fixed to intermediate members, respectively, and are fixed to the surface of the member to be measured through the intermediate members. The fixing point of the ceramic thin film to the member, the fixing point of the intermediate member to the member to be measured, and the material of the intermediate member are determined so as to cancel the difference in thermal expansion between the ceramic thin film and the member to be measured. To do. Although the intermediate member may be directly fixed to the member to be measured, it may be fixed to the member to be measured indirectly, that is, through another plate-shaped member. When the intermediate member is fixed to the member to be measured via another member having a flat plate shape, the above-mentioned "fixing position of the intermediate member to the member to be measured" is read as a fixing position of the intermediate member to the other member. Also in the method of this claim, one or a plurality of ceramic thin films are used for one member to be measured, similarly to the above. The method of this claim is, for example,
As shown in FIG. 9A or 9B, the ceramic thin film 2
It can be carried out by using the intermediate member 6 or the like.

According to this method, it is possible to prevent the ceramic thin film from being stretched or broken only by the temperature change. This is because even if a difference in thermal expansion occurs between the ceramic thin film and the member to be measured due to a temperature change, the difference is canceled by the action of the intermediate member or the like used as described above. If the difference in thermal expansion is canceled out, it becomes possible to precisely measure the elongation of the member to be measured at high temperature.

In order to cancel the difference in thermal expansion, in the example of FIG. 9A, the coefficient of linear expansion of the ceramic thin film 2 is α ₂ flat plate 4 (made of the same material as the member to be measured. Linear expansion coefficient: α ₄ Linear expansion coefficient of the intermediate member 6: α ₆ Span between two fixed portions of the flat plate 4 and the intermediate member 6: L
_{1 When} the span between the two fixing portions of the ceramic thin film 2 and the intermediate member 6 is L ₂ , α ₆ = (α ₄ L ₁ −α ₂ L ₂ ) / (L ₁ −L ₂ ) ... (A) is satisfied. The span L _1, L ₂ can be appropriately determined according to the linear expansion coefficient alpha ₆ appropriately select or linear expansion coefficient alpha _6, the intermediate member 6 in response to the span L _1, L _2.

In the measuring method according to the third aspect, in particular, a film of a conductive material is formed in advance on the surface of the ceramic thin film (that is, before the start of the measurement), and after the high temperature elongation occurs, the conductivity is reduced. The feature is that whether or not the ceramic thin film is broken is detected depending on whether or not the material film can be energized.
The film of the conductive material can be formed by, for example, depositing aluminum or a heat-resistant alloy on the surface of the ceramic thin film.

According to this measuring method, the presence or absence of breakage of the ceramic thin film can be detected more reliably and in a shorter time than by visual inspection. When the ceramic thin film is broken, the coating of the conductive material is also interrupted at the same time, so that whether or not the current can be passed is accurately indicated whether or not there is a break, and the current test can be performed very easily. In addition to being able to detect small breaks that are difficult to confirm by visual inspection, it is convenient when measuring parts that are difficult to see visually.

According to a fourth aspect of the present invention, a sensor for measuring high temperature elongation is obtained by fixing both ends of a ceramic thin film having a known elongation at break on a flat plate made of the same material as the member to be measured.

If this sensor is used in such a manner that the flat plate portion is fixed to the surface of the member to be measured, the measuring method described in claim 1 can be carried out smoothly. That is, since the ceramic thin film is fixed on the flat plate that causes high temperature elongation together with the member to be measured, it is possible to perform the measurement even at a high temperature condition exceeding 600 ° C., and to know the high temperature elongation of the member to be measured accurately. be able to.

Further, in this sensor, since the ceramic thin film is fixed on the flat plate, it is easy to handle although the thin film is easily broken. In particular, since the material of the flat plate is the same as that of the member to be measured, it is easy to fix them between each other, that is, between the plate and the member to be measured. High followability of growth. From this point of view, the sensor according to the present invention facilitates highly accurate measurement.

The measuring sensor according to a fifth aspect of the present invention further comprises a plurality of ceramic thin films having different known breaking elongations due to different materials or shapes arranged in the same length direction (that is, the above flat plate shape). Is fixed to).

By using such a sensor, the high temperature elongation of the member to be measured can be specified in a narrower range, and highly accurate measurement can be performed. As described in the method of claim 1, when a plurality of ceramic thin films having different breaking elongations are used at the same time, the elongation of the measured member is
This is because it can be specified that among the plurality of thin films, the fracture elongation of the fractured ones is larger than the maximum value, and the fracture elongation of the non-broken ones is less than the minimum value. When the number of ceramic thin films is increased and the step between break elongations of the respective thin films is made finer, the measurement accuracy is further enhanced.

In particular, the measuring sensor according to claim 6 is:
As the ceramic thin film, one having a curved portion (a curved portion) between both ends is used. For example, the sensors shown in FIGS. 6 to 8 exemplify the measurement sensor of this claim.

In general, the elongation at break of the ceramic material is in the range of 1% or less, so that the creep elongation and the like of the metal member or the like may not be sufficiently measured normally. But,
When a ceramic thin film having a curved portion is used according to the above, since the thin film can follow the elongation of the member to be measured by deforming the curved portion (changing the curvature), the original breaking elongation is small. It is possible to measure a large elongation (for example, 1% or more) while using a ceramic material. Therefore, it can be said that this measuring sensor can be used for a wide range of high temperature elongation measurement including a case where elongation is large (for example, measurement of creep elongation of a metal material).

According to a seventh aspect of the present invention, further, both ends of the ceramic thin film are fixed to the flat plate through intermediate members, and the ceramic thin film is fixed to the intermediate member and the intermediate plate is fixed. Where parts are fixed,
And the material of the intermediate member is set so as to cancel the difference in thermal expansion between the ceramic thin film and the member to be measured. The sensor of FIG. 9A or 9B is an example corresponding to the sensor of this claim.

According to such a sensor, the measuring method described in claim 2 can be easily implemented. The respective fixing points and materials are defined in the same manner as described in the method of claim 2. Since the difference in thermal expansion between the ceramic thin film and the member to be measured is offset, the high temperature elongation of the member to be measured can be accurately measured. In addition, since the ceramic thin film and the intermediate member are fixed on the flat plate, the thin film is easy to handle as a sensor even though the thin film is easily broken. Since the ceramic thin film and the intermediate member can be fixed to the flat plate not at the measurement site of high temperature elongation but at a specialized manufacturing site, it is possible to appropriately set the above-mentioned fixing position, etc. The points also facilitate high-precision measurement.

The sensor according to claim 8 is the sensor according to claim 7, wherein, for example, as shown in FIG. 9B, the interval L ₂ between the fixing points of the ceramic thin film 2 (both ends thereof) to the intermediate member 6 is It is characterized in that it is made wider than the interval L ₁ between the fixing points of the intermediate member 6 to the flat plate 4. In this case, according to the above formula (A), the linear expansion coefficient α ₆ of the intermediate member ₆ can be calculated from the linear expansion coefficient α ₄ of the flat plate 4 (the same material as the member to be measured) and the ceramic thin film 2 Must be smaller than any of the linear expansion coefficients α ₂ . Therefore, it is suitable to use a ceramic material having a small linear expansion coefficient such as silicon nitride, silicon carbide, or mullite as the intermediate member.

With this sensor, in addition to offsetting the difference in thermal expansion between the ceramic thin film and the member to be measured to enable highly accurate measurement, etc., measurement can be performed even when the member to be measured has a large elongation. Brings the effect of enabling. The space between the fixing points of the ceramic thin film to the intermediate member (Fig. 9 (b)).
L ₂ ) of the intermediate member is made wider than the interval (the same L ₁ ) of the fixing points of the intermediate member to the flat plate, the sensitivity of the elongation of the ceramic thin film increases, and the small (low ratio) elongation of the thin film causes the member to be measured. This is because a large (high ratio) elongation of can be measured. Therefore, this sensor, like the sensor of claim 6, can measure a large elongation while using a ceramic material, which originally has a small elongation at break, as a raw material, and can be used for a wide range of high temperature elongation measurement.

The sensor for measurement according to claim 9 is characterized in that a ceramic thin film made of single crystal ceramic is used. Since the single crystal ceramic is less likely to cause material defects and has uniform characteristics, the elongation of the member to be measured can be measured with high accuracy.

The sensor according to claim 10 is characterized in that a film of a conductive material is formed on the surface of the ceramic thin film, and lead wires are connected to both ends of the film, respectively. By using this sensor, the method of claim 3 can be easily realized, and the presence or absence of breakage of the ceramic thin film can be detected reliably and easily in a short time. The fact that the thin film is fractured can be easily detected, which means that the high temperature elongation of the member to be measured can be easily measured.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the invention relating to measurement of high temperature elongation will be described below with reference to the drawings. 1-10
3A and 3B are drawings respectively illustrating a high temperature elongation measuring method or a measuring sensor.

In the first embodiment shown in FIG. 1, a rectangular ceramic thin film 2 having notches 3 on both sides at the center in the length direction is used. Both ends 2a of this thin film 2 are
The member to be measured 4 is fixed directly on the surface of the member to be measured 44.
After using 4 at high temperature, the presence or absence of breakage of the ceramic thin film 2 is visually confirmed. If it is broken, it can be seen that the high temperature elongation (creep elongation etc.) of the member to be measured 44 exceeds the set value (break elongation of the thin film 2).

The breaking elongation (%) of the ceramic thin film 2 is 1
Since it does not change significantly even at high temperatures exceeding 000 ° C, highly accurate measurement can be performed. Elongation at break varies depending on the ceramic material, with 0.09 to 0.12% alumina,
Mullite about 0.13%, titania about 0.12%, silicon carbide about 0.13%, silicon nitride 0.2-0.3.
%, Zirconia is 0.35 to 0.7%, and cermet is 0.35 to 0.45%. For example, from these, a ceramic material having a breaking elongation corresponding to the high temperature elongation set limit value of the member to be measured 44 is selected and used as the thin film 2. If a single crystal ceramic material is used, material defects are less likely to occur and the characteristics are uniform, so that the variation in breaking elongation is small.

Ceramic thin film 2 for the member to be measured 44
When fixing the two, both ends 2
In a, it is preferable to adopt a method by thermal spraying or adhesion using ceramics. Figure 1 (or the figure below)
Inside, the black portions such as the both end portions 2a are fixed or fixed portions. As a method by thermal spraying, there is, for example, a rocaide system thermal spraying method used for fixing a high temperature strain gauge. In this method, rod-shaped ceramics (such as alumina) are melted with oxygen / acetylene flame,
It is directly blown to both ends 2a of the ceramic thin film 2 by atomized air (mixed air of atomically ground ceramics). Generally, a ceramic adhesive is one in which an inorganic binder, which is vitrified by heating, a ceramic filler, and water as a solvent are baked at an intermediate temperature (90 to 400 ° C.) so as to exhibit an adhesive force.
Alumina, zirconia, magnesia, etc. are used as the filler. The heat resistant temperature is 1600 ° C. or higher. Such an adhesive is applied to the lower surface of both ends 2a to bond the ceramic thin film 2 to the member to be measured 44.

In the second embodiment shown in FIG. 2, a second ceramic thin film 2'having a breaking elongation different from that of the ceramic thin film 2 is fixed in parallel with the thin film 2 to the member to be measured 44. . By using the same ceramic material for the two thin films 2 and 2'to prevent a difference in thermal expansion between them, and by making the shape of the notch 3'different from the notch 3, Make a difference in breaking elongation.

If the member 44 to be measured, to which the ceramic thin film 2.2 'is fixed, is used at a high temperature and both of the two thin films 2.2' rupture, the elongation generated in the measuring member 44 will be two. It can be seen that the elongation at break was greater than that of either of the thin films 2 and 2 ', and if only one of them was broken, it was found that an elongation of an intermediate size between the respective break elongations of the thin films 2.2 and 2 occurred.

In the illustrated example, two ceramic thin films 2.
Although 2'is used, the increase in the number can reduce the break elongation breakage, so that the range in which the elongation of the measured member 44 is included is narrowed and the measurement accuracy is improved. In order to provide a difference in breaking elongation of each thin film while using an equivalent ceramic material, for example, as shown in FIGS. 5A to 5F, notches of various shapes and dimensions are formed in each thin film 2. It is good to form. The breaking elongation differs for each thin film 2 depending on the degree of concentration of stress generated in the vicinity of the notch.

In the third embodiment shown in FIG. 3, the ceramic thin film 2 is fixed on the flat plate 4 made of the same material as the member to be measured 44, and the surface of the member to be measured 44 is used as the measuring sensor 1. Then, the measurement is performed in the same manner as in the first embodiment. The thin film 2 is fixed to the flat plate 4 at both ends 2a of the thin film 2 by the above-mentioned adhesion or thermal spraying, and the flat plate 4 is fixed to the member to be measured 44 by spot welding or the like. Although the ceramic thin film 2 is easily broken, it is easy to handle because it is fixed to the flat plate 4 in advance.
Since the flat plate 4 and the member to be measured 44 are made of the same material, it is easy to fix the sensor 1 and there is no disadvantage in measurement accuracy.

The measuring sensor 11 shown in FIG. 4 has two ceramic thin films 2 and 2'having different breaking elongations fixed to the surface of a flat plate 4 made of the same material as the member 44 to be measured. is there. This is used by fixing it on the surface of the member to be measured 44. The adhesion of each thin film 2 and 2'to the flat plate 4 is
Similar to the third embodiment, the above-mentioned adhesion or thermal spraying is performed. Also in such a sensor 11, FIG.
An appropriate number of thin films 2 having notches of various shapes illustrated in (f) can be used.

The breaking elongation peculiar to the material of the ceramic material is generally less than 1%, but the breaking elongation as the thin film 2 can be increased by devising the shape of the ceramic thin film 2. For example, in the measurement sensor 31 shown in FIG. 6, the ceramic thin film 2 is bent to form a curved portion 2b (a portion that bypasses a straight line between both end portions 2a) between both end portions 2a fixed to the flat plate 4. By giving a margin to the length, the amount of elongation until rupture is increased.

The measuring sensor 4 shown in FIGS. 7 (a) to 7 (d).
In each of the examples 1, the ceramic thin film 2 is formed like a spring, and each has a curved portion 2b, and then both end portions 2a are fixed to the flat plate 4. These are also curved parts 2
The elongation at break is increased by utilizing b.

The measuring sensor 51a shown in FIGS. 8 (a) to 8 (c).
51b and 51c each have both ends thereof attached to the flat plate 4 by slackening the fibrous ceramic thin film 22 (providing the curved portion 22b). By adjusting the amount of slack appropriately, it is possible to break at an arbitrary elongation amount larger than the elongation at break inherent to the material.

In the measuring sensor 51a shown in FIG. 8A, both ends of the ceramic fiber (thin film) 22 are fixed with a ceramic adhesive in the recesses 4a provided on the lower surfaces of both ends of the flat plate 4. The measurement sensor 51b of FIG. 8B fixes the both ends of a plurality of ceramic fibers 22 having slightly different lengths to the flat plate 4, and determines the length of the flat plate 4 depending on which length of the ceramic fiber 22 is broken. (That is, the elongation of the member to be measured to which the flat plate 4 is fixed) can be accurately measured. Further, in the measurement sensor 51c of FIG. 8C, both ends of the ceramic fiber 22 are embedded in both ends of the flat plate 4 by melting a part of the flat plate 4 once.

9A and 9B, the intermediate member 6 is integrated between the both ends 2a of the ceramic thin film 2 and the flat plate 4 (of the same material as the member to be measured 44). The sensors 21 and 21 'are shown. Regarding the linear expansion coefficient of each member, the flat plate 4: α ₄ , the intermediate member 6: α ₆ , the ceramic thin film 2:
α ₂ and both ends 6a of the intermediate member 6 fixed on the flat plate 4
If the span between them is L ₁ and the span between both ends 2 a of the thin film 2 fixed on the intermediate member 6 is L ₂ , then α ₆ = (α ₄ L ₁ −α ₂ L ₂ ) / (L ₁ −L ₂ ) (A) or a modified version of L ₂ / L ₁ = (α ₄ −α ₆ ) / (α ₂ −α ₆ ) ... (B), the ceramic thin film 2 and the member to be measured 44 are satisfied.
Since the difference in thermal expansion that tends to occur with (the same material as the flat plate 4) can be offset, high temperature elongation such as creep elongation can be measured with high accuracy.

In the example of FIG. 9, stainless steel (SUS31
The high temperature elongation of the member to be measured 44 made in 6) was measured using the same stainless steel flat plate 4 (coefficient of linear expansion α ₄ = 18.5 × 10 ⁻⁵ /
° C) and a zirconia thin film 2 (α ₂ = 11 × 10 ^-5 /
The temperature is measured by the sensor 21 or 21 ′ including (° C.). First, the sensor 21 of FIG. 9A is an example in which a metal material having a relatively large linear expansion coefficient α ₆ (about 20 × 10 ⁻⁵ / ° C. or more) is used as the intermediate member 6. From the condition of the above formula (A) or (B), the span L ₁ becomes longer than the span L ₂ .

On the other hand, in the sensor 21 'shown in FIG. 9B, the intermediate member 6 is made of silicon nitride (α ₆ ≈3) having a small linear expansion coefficient α _6.
(× 10 ⁻⁵ / ° C.) A metal material is used. Again, in order to satisfy the above formula (A) or (B), L ₂ / L ₁ = 1.94, and the span L ₂ exceeds the span L ₁ as shown in the figure.

In the sensor 21 'employing the spans L ₁ and L ₂ as described above, the difference in thermal expansion between the flat plate 4 and the thin film 2 is canceled out, and the high temperature elongation can be measured with high accuracy. There is also an advantage that the range is expanded. That is, when the flat plate 4 is stretched by 1% together with the member to be measured, the elongation of the thin film 2 is 0.01 × L ₁ / L ₂ = 0.01 × L ₁ /(1.94×L ₁ ) = 0.0052. This is because the growth is limited to about 0.5%.
That is, the elongation at break of zirconia, which is the material of the thin film 2, is originally around 0.6%, but the elongation sensitivity of the thin film 2 is 1.94 by setting the spans L ₁ and L ₂ as described above.
That is, the high temperature elongation (creep elongation etc.) of about 1% occurring in the member to be measured 44 can be sufficiently measured.

FIG. 10 shows a ceramic thin film 12 on the surface of which a conductive material film 7 is formed. The film 7 is formed by vacuum deposition of aluminum, for example, and lead wires 8 are attached to both ends of the film conductive film 7. When this thin film 12 is used, when it breaks due to high-temperature elongation, the conductive thin film 7 loses electrical continuity due to cracks. Therefore, the presence or absence of breakage, that is, the magnitude of high-temperature elongation generated in the member to be measured can be determined easily and easily. You can know for sure.

[0046]

According to the high temperature elongation measuring method of the present invention, 6
It is possible to easily measure the elongation of the member to be measured at high temperature including the case of 00 ° C. or higher. Since a ceramic thin film is used, a) measurement can be performed even at a temperature of, for example, 1000 ° C., b) the ductility and elongation at break of the thin film hardly change with temperature, so the measurement accuracy is high.
Since the thin film is less likely to be oxidized or corroded, the thin film can be downsized while maintaining the measurement accuracy. According to the measuring method described in claim 2, the difference in thermal expansion, which tends to occur between the ceramic thin film and the member to be measured due to the temperature change, is canceled out, so that the elongation of the member to be measured at high temperature is accurately measured. Can be measured. According to the measuring method of the third aspect, the presence or absence of breakage of the ceramic thin film, and thus the high temperature elongation generated in the member to be measured can be reliably detected in a short time.

According to the high temperature elongation measuring sensor described in claim 4, the measuring method described in claim 1 can be smoothly carried out, and the above-mentioned effects are brought about. Further, since the ceramic thin film is fixed on a flat plate having the same material as the member to be measured, it is easy to handle and satisfactory in terms of measurement accuracy. With the measuring sensor according to claim 5, the high temperature elongation of the member to be measured can be specified in a narrower range,
Therefore, the measurement can be performed with higher accuracy.
The measuring sensor according to the sixth aspect can be used for a wide range of high temperature elongation measurement including a case where a generated elongation is large, while using a ceramic material which originally has a small elongation at break.

According to the measuring sensor of claim 7,
The measuring method described in claim 2 can be easily implemented and the above-mentioned effects can be obtained. In addition to being easy to handle, there is an effect that the intermediate member and the ceramic thin film can be properly and accurately fixed to the flat plate, and also from that point, highly accurate measurement is possible. With the sensor according to the eighth aspect, it is possible to perform a high temperature elongation measurement in a wide range including a case where a generated elongation is large, while using a ceramic material which originally has a small elongation at break.

The measuring sensor according to claim 9 is particularly advantageous for highly accurate measurement. With the sensor according to claim 10, the method according to claim 3 can be easily realized, and the presence or absence of breakage of the ceramic thin film, and therefore the high temperature elongation of the member to be measured can be detected reliably and easily in a short time. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment relating to measurement of high temperature elongation according to the present invention.

FIG. 2 is a perspective view showing an embodiment relating to measurement of high temperature elongation according to the present invention.

FIG. 3 is a perspective view showing an example of measurement of high temperature elongation according to the present invention.

FIG. 4 is a perspective view showing an embodiment relating to measurement of high temperature elongation according to the present invention.

5 (a) to 5 (f) are plan views each showing an example of the ceramic thin film 2. FIG.

FIG. 6 is a perspective view showing an embodiment relating to measurement of high temperature elongation according to the present invention.

7 (a) to 7 (d) are perspective views or plan views each showing an embodiment relating to measurement of high temperature elongation according to the present invention.

8 (a) to 8 (c) are side views or perspective views, respectively, showing an embodiment relating to the measurement of high temperature elongation according to the present invention.

9 (a) and 9 (b) are side views each showing an embodiment relating to measurement of high temperature elongation according to the present invention.

FIG. 10 is a perspective view showing an embodiment relating to measurement of high temperature elongation according to the present invention.

FIG. 11 is a plan view showing a conventional stress measurement sensor (see FIG.
It is (a)) and a side view (the same (b)).

[Explanation of symbols]

1 Measuring sensor 2 Ceramic thin film 3 notches 4 flat plate 6 Intermediate member 7 Conductive film 8 lead wires 44 Measured member

Claims (10)

[Claims] 1. A ceramic thin film having a known elongation at break is fixed on the surface of a member to be measured, and after the high temperature elongation occurs, the elongation of the member to be measured is known by the presence or absence of breakage of the ceramic thin film. Measuring method of high temperature elongation. 2. Both ends of the ceramic thin film are fixed to an intermediate member, respectively, and are fixed to the surface of the member to be measured through the intermediate member. At that time, the ceramic thin film is fixed to the intermediate member. The high temperature elongation according to claim 1, wherein a fixing point of the intermediate member to the member to be measured and a material of the intermediate member are set so as to cancel a difference in thermal expansion between the ceramic thin film and the member to be measured. Measuring method. 3. A ceramic thin film is previously formed with a film of a conductive material, and after the high temperature elongation occurs, the presence or absence of breakage of the ceramic thin film is detected depending on whether or not the film can be energized. The method for measuring high temperature elongation according to claim 1 or 2, characterized in that. 4. A sensor for measuring high-temperature elongation, characterized in that both ends of a ceramic thin film having a known breaking elongation are fixed on a flat plate made of the same material as the member to be measured. 5. The high temperature elongation according to claim 4, wherein a plurality of ceramic thin films having different known breaking elongations due to different materials or shapes are arranged in the same length direction. Measuring sensor. 6. The high temperature elongation measuring sensor according to claim 4, wherein the ceramic thin film has curved portions between both ends. 7. Both ends of the ceramic thin film are fixed to the flat plate through an intermediate member, respectively, and the ceramic thin film is fixed to the intermediate member, the intermediate member is fixed to the flat plate, and the intermediate portion is formed. 7. The high temperature elongation measuring sensor according to claim 4, wherein the material of the member is capable of canceling the difference in thermal expansion between the ceramic thin film and the member to be measured. 8. The sensor for measuring high temperature elongation according to claim 7, wherein the distance between the fixing points of the ceramic thin film to the intermediate member is wider than the distance between the fixing points of the intermediate member to the flat plate. 9. The high temperature elongation measuring sensor according to claim 4, wherein the ceramic thin film is made of a single crystal ceramic. 10. The high temperature according to claim 4, wherein a coating of a conductive material is formed on the surface of the ceramic thin film, and lead wires are connected to both ends of the coating. A sensor for measuring elongation.