JP7149900B2 - Observation sample holding jig for tilt CT - Google Patents

Description

The present invention relates to an observation sample holding jig for tilt CT.

A CT (Computed Tomography) method is known as a method for nondestructive three-dimensional measurement of an observation sample. As such a CT method, in recent years, a normal CT method as schematically shown in FIG. 1 and an inclined CT method as schematically shown in FIG. 2 are used.

Here, referring to FIG. 1, when the flat plate-shaped observation sample OS is usually measured by the CT method, the flat plate-shaped observation sample OS is rotated about the rotation axis C and is perpendicular to the rotation axis C. Measurement is performed by irradiating electromagnetic waves (for example, X-rays, etc.) from the direction of In such a measurement, the transmission distance of the electromagnetic wave in the observation sample OS becomes longer (the electromagnetic wave needs to pass through the sample by the length of the observation sample OS in the direction orthogonal to the thickness direction), and the observation The transmittance of the electromagnetic waves in the sample OS is low, and there is a problem that an unclear image is displayed on the screen S, and in some cases, only a pure black (or pure white) image is displayed. Therefore, it has been difficult to measure the internal structure of the flat observation sample OS by the normal CT method.

On the other hand, as shown in FIG. 2, an oblique CT method in which an electromagnetic wave is emitted while the rotation axis C is tilted with respect to the irradiation direction of the electromagnetic wave (such an oblique CT method is also called "laminography CT"). ), the transmission distance of the electromagnetic wave in the observation sample OS becomes short, so that the image I is projected on the screen S by the electromagnetic wave transmitted through the observation sample OS, and by analyzing this image I, the observation sample OS It is possible to observe the internal structure of the OS non-destructively and three-dimensionally. Therefore, the tilt CT method can be suitably used particularly when measuring the internal structure of a thin film or sheet-shaped sample that is usually unsuitable for measurement by the CT method, such as a flat observation sample OS. be.

Regarding a holding jig for an observation sample that is used for non-destructive three-dimensional measurement of an internal structure by such a tilt CT method, for example, Japanese Patent Application Laid-Open No. 2003-329616 (Patent Document 1) discloses a eucentric table. It is In addition, Ante Buljac et al.'s paper "In Situ Observation Of Strained In Bands And Ductile Damage In Thin AA2139-T3 Alloy Sheets” (Non-Patent Document 1), in the figures (a) and (b), a tensile force is applied to the slit formed in the flat observation sample. An apparatus is disclosed that enables observation of the tip of the slit by laminography CT. In addition to the jigs described in these documents, for example, the website of Flex Service Co., Ltd. (URL: https://www.flex- service.com/file/X-CT.pdf) discloses "Tension Compression Tester for X-ray CT/Synchrotron".

2003-329616

Paper: Ante Buljac et al., “In Situ Observation Of Strained Bands And Ductile Damage In Thin AA2139-T3 Alloy Sheets”, Procedia IUTAM, Vol.20, Elsevier, 2017, P.66-P.72 Website of Flex Service Co., Ltd. (URL: https://www.flex-service.com/file/X-CT.pdf)

However, the jig for holding the observation sample described in Patent Literature 1 cannot apply a compressive force to the observation sample. I couldn't do it. In addition, although the jig for holding the observation sample as described in Non-Patent Document 1 can apply a tensile force to the observation sample, it cannot apply a compressive force to the observation sample. The flesh structure could not be observed by laminography CT under compression force. Furthermore, although the jig for holding the observation sample as described in Non-Patent Document 2 is capable of applying a compressive force to the observation sample, it is used for measurement by the so-called laminography CT method, and it is used in an oblique direction. Even if an electromagnetic wave is emitted from the jig, the jig blocks the transmission of the electromagnetic wave. For these reasons, the jig described in Non-Patent Document 2 could not be used for measurement by the laminography CT method.

The present invention has been made in view of the above-described problems of the prior art, and makes it possible to perform measurement by the tilt CT method while applying a sufficiently high compressive force to the observation sample, and to observe the compressed state. It is an object of the present invention to provide an observation sample holding jig for tilt CT that enables non-destructive three-dimensional measurement of the internal structure of a sample with higher accuracy.

As a result of intensive studies aimed at achieving the above object, the inventors of the present invention have found that an observation specimen holding jig used for measurement by a tilt CT method using electromagnetic waves is a container having a cavity for accommodating an observation specimen. and compression means for compressing and sandwiching the observation sample with two indenters in the cavity of the container; each of the two indenters is made of a material that has a transmittance of 5% or more for the electromagnetic wave used for measurement. and a portion that supports the tip and is made of a material having a compressive strength of 100 MPa or more measured at a temperature of 23° C. in accordance with JIS K7181. and at least one of the two indenters is arranged so that the support is in contact with any part of the inner surface of the container, and the support By making the area of the container contacting surface of the support part 5 to 100 times larger than the area of the tip contacting part of the support part, a sufficiently high compressive force is applied to the observation sample. It is possible to perform measurement by the tilt CT method while observing, and it is possible to perform non-destructive three-dimensional measurement of the internal structure of the observation sample in a compressed state with higher accuracy. Arrived.

That is, the observation sample holding jig for tilt CT of the present invention is an observation sample holding jig used for measurement by the tilt CT method using electromagnetic waves,
A container having a cavity for containing an observation sample, and compression means for compressing and sandwiching the observation sample in the cavity of the container with two indenters,
Each of the two indenters is made of a material having a transmittance of 5% or more for the electromagnetic wave used for measurement, and has a tip end portion having a surface to be brought into contact with the observation sample, and a temperature condition of 23 ° C. in accordance with JIS K7181. and a support portion that is a portion that supports the tip portion and is made of a material having a compressive strength of 100 MPa or more as measured in
At least one of the two indenters is arranged so that the support portion abuts on any portion of the inner surface of the container, and the area of the container contact surface of the support portion is equal to that of the support portion. Having a size 5 to 100 times larger than the area of the tip contact portion,
It is characterized by

In the observation sample holding jig for inclined CT according to the present invention, the indenter arranged so that the support portion abuts on any portion of the inner surface of the container is provided on the container contact surface of the support portion. It is preferable that the area is 8 to 10 times as large as the area of the tip contact portion of the support portion.

Further, in the observation sample holding jig for inclined CT of the present invention, it is preferable that the supporting portion is made of a material having the compressive strength of 100 MPa to 300 MPa.

According to the present invention, it is possible to perform measurement by the tilt CT method while applying a sufficiently high compressive force to the observation sample, and perform non-destructive three-dimensional measurement of the internal structure of the observation sample in a compressed state. It is possible to provide an observation sample holding jig for tilt CT that enables more accurate observation.

FIG. 2 is a schematic diagram schematically showing the relationship between a flat observation sample, electromagnetic waves, and a screen when performing measurement using a so-called normal CT method. FIG. 2 is a schematic diagram schematically showing the relationship between a flat observation sample, electromagnetic waves, and a screen when performing measurement using a so-called tilt CT method. 1 is a perspective view schematically showing a preferred embodiment of a jig for an oblique CT apparatus that includes an observation sample holding jig; FIG. 4 is a longitudinal sectional view schematically showing a part of the A-A' section of the jig shown in FIG. 3; FIG. FIG. 5 is a schematic diagram (enlarged view of the compression means) schematically showing an enlarged compression means shown in FIG. 4 ;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted. In addition, in the following description and drawings, specific shapes, materials, numerical values, directions, etc. are examples for facilitating understanding of the present invention, and may be changed as appropriate according to usage, purpose, specifications, etc. is possible.

First, a preferred embodiment of an observation sample holding jig for tilt CT according to the present invention will be described with reference to FIGS. FIG. 3 is a perspective view schematically showing a preferred embodiment of a jig for an oblique CT apparatus including the observation sample holding jig 10. As shown in FIG. FIG. 4 schematically shows a part of the AA' cross section of the jig shown in FIG. It is a schematic cross-sectional view showing. The A-A' cross section is a plane including the rotation axis C (central axis) shown in FIG. 5 is an enlarged view schematically showing the compressing means 12 included in the observation sample holding jig 10 shown in FIG.

In the embodiment shown in FIGS. 3 to 5, the observation sample holding jig 10 comprises a container 11, compression means 12, and a compression force applying mechanism 13. FIG. Here, the compressing means 12 of the present embodiment is composed of a lower indenter 121 that contacts the container and an upper indenter 122 that is connected to the compressive force applying mechanism 13, and the compressive force is applied by the compressive force applying mechanism 13. Thus, the observation sample OS can be held while being compressed. As shown in FIGS. 3 and 4, the observation sample holding jig 10 is fixed to the mounting member 20 by a fixture 50 at the flange portion of the container 11 (the portion projecting outward from the cylindrical container portion). ing.

Further, as shown in FIG. 3, the observation sample holding jig 10 is fixed to a rotating stage 30 of the tilt CT apparatus via a mounting member 20, and is rotatable about a rotation axis C. . In the tilt CT measurement, the internal structure is reconstructed by performing angle correction according to the tilt angle of the observation sample OS (the tilt angle of the rotation axis C with respect to the irradiation axis of the electromagnetic wave E at the time of measurement in the so-called oblique CT measurement). This is a measurement that obtains a transmission image by Therefore, in order to obtain a more accurate transmission image, it is preferable to rotate the observation sample OS by 360° for measurement. It is more preferable to use one that is rotationally symmetrical about the axis C. From this point of view, in this embodiment, the container 11, the compressing means 12, the compressive force applying mechanism 13, the mounting member 20, and the rotating stage 30 are all rotationally symmetrical with respect to the rotation axis C. .

In FIGS. 4 and 5, an arrow indicated by E conceptually indicates an electromagnetic wave and its traveling direction (irradiation direction: irradiation axis: traveling path of the electromagnetic wave). Here, the electromagnetic wave E used for tilt CT is not particularly limited as long as it can be used for CT measurement. It is preferable to appropriately select and use an appropriate radiation source from the constituent materials.

The container 11 constituting such an observation sample holding jig 10 is formed with a space (cavity) for accommodating the observation sample OS therein. That is, such a container 11 is not particularly limited as long as it has a hollow portion for containing the observation sample OS, and is capable of containing at least part of the observation sample OS and compression means 12 described later. , a known container (casing) can be used as appropriate.

In addition, as shown in FIG. 4, the container (housing) 11 exists on the traveling path of the electromagnetic wave E, so at least the portion of the container 11 that exists on the traveling path of the electromagnetic wave E receives the electromagnetic wave E. It must be made of a material that is permeable. In this way, from the viewpoint of transmitting the electromagnetic wave E, it is preferable that at least a portion of the container 11 that is in the travel path of the electromagnetic wave E is made of a material having higher permeability to the electromagnetic wave E than a metal material. , more preferably made of a resin material. In addition, from the viewpoint of ease of manufacture, such a container 11 is preferably made of the same material that has a higher permeability to electromagnetic waves E than a metal material. It is more preferable to be formed with Examples of such a resin material include, but are not particularly limited to, acrylic resin, polyetheretherketone (PEEK), phenolic resin (Bakelite), and the like.

Note that when a compressive force is applied to the observation sample OS, the same tensile stress as the compressive force is applied to the container 11 . That is, when a stress (compressive force) is applied to the lower side by the compressive force imparting mechanism 13, a downward stress is also applied to the container 11 by the lower indenter 121A as a result. A tensile stress with the same force as the force is applied. Therefore, in manufacturing the container 11, it is preferable to use a material having high mechanical strength to the extent that it is not damaged by the tensile stress as described above. It is conceivable to increase the thickness of the wall surface in consideration of the stress applied to the container. (because the transmission distance in the wall surface becomes long), it is preferable to make the thickness of the electromagnetic wave transmitting portion thinner. From such a point of view, increasing the wall thickness to increase the mechanical strength of the container 11 is practically difficult to adopt from the point of view of highly accurate measurement. Further, for example, by enlarging the cylinder of the container 11 (increasing the outer diameter R1), the cross-sectional area is ensured, and by increasing the area of the connecting portion of the lower indenter 121A, sufficient strength of the container 11 is obtained. However, it is highly necessary to reduce the influence of refraction in order to obtain a more accurate transmission image, and it is preferable to make the distance between the observation sample OS and the electromagnetic wave detector as close as possible. Therefore, increasing the outer diameter R1 of the container 11 is also practically difficult to adopt from the viewpoint of performing highly accurate measurements. From this point of view, the outer diameter of the container 11 (maximum outer diameter of the portion excluding the flange) R1 is not particularly limited, but it is more preferably about 10 to 30 mm. Although the thickness T of the side wall portion of is not particularly limited, the thickness T of the side wall portion is not particularly limited, but from the viewpoint of improving the transmittance of the electromagnetic wave E when it passes through the side wall portion by making the transmission distance of the electromagnetic wave E shorter, and the thickness T of the container is higher. From the viewpoint of obtaining strength, it is more preferable to set the thickness to about 1.5 to 2.5 mm. Also, the height H1 of the container 11 from the portion of the container 11 that abuts on the mounting member 20 is not particularly limited, but is set to 60 mm or less from the viewpoint of preventing deviation of the rotation axis during tilt CT measurement due to deflection. is more preferred. Furthermore, the thickness H2 of the flange portion provided for connecting with the mounting member of the container 11 is not particularly limited, but it is necessary to disperse the tensile stress generated as a reaction force when compressive force is applied to the sample, and to allow observation. It is more preferable to set it to about 5 to 10 mm from the viewpoint of preventing the shift into the field of view.

In addition, the wall surface of the container 11 on which the electromagnetic wave E is incident is formed obliquely with respect to the rotation axis C. In the CT measurement, a configuration is used in which the incident angle of the electromagnetic wave E to the container 11 is substantially vertical. As described above, when the incident angle of the electromagnetic wave E to the container 11 is substantially vertical (preferably about 90°±10°), the wall thickness is constant, and the penetration distance of the electromagnetic wave E is shortened. It becomes possible to further improve the transmittance of the electromagnetic wave E when passing through the portion.

Further, the container 11 includes an upper structure (upper structure) including a top plate (ceiling portion) and a side wall portion parallel to the rotation axis C, and a bottom portion of the container 11 and the rotation axis C. and a lower structure (lower structure) including portions of oblique sidewalls. Moreover, the upper structure of such a container 11 has a cylindrical shape provided with a flange portion, and the inside is hollow. The lower structure of the container 11 has a shape in which a concave portion having an opening at the top is formed by a bottom portion and an oblique side wall, and a flange portion is formed on the outside. In this way, the upper structure and the lower structure of the container 11 are formed with flange portions (portions that protrude outward), and are fixed by the fixtures 50 at these flange portions. Such fixtures 50 are not particularly limited, and known fixtures can be used as appropriate. For example, screws or the like may be used. It should be noted that it is preferable to use a detachable fixture 50, so that the upper structure of the container can be removed like a lid at the time of use, and the observation sample OS can be accommodated or replaced. becomes easier.

In addition, on the bottom surface of the container 11 (the bottom surface of the recess of the lower structure), a circular surface having the same size as the container contact surface S3 of the lower indenter 121 is provided in the portion on which the lower indenter 121 is placed. A columnar projection (projection) P1 is provided. By providing such a projecting portion P1, the direction of the force received from the lower indenter 12 (press pressure on the container) and the direction of the stress generated as the reaction force thereof are parallel to the rotation axis C. there is In this way, the direction of the force (pressing pressure on the container) received from the lower indenter 12 and the stress generated as its reaction force are parallel to the rotation axis C, and the protrusion P1 on the bottom surface is positioned downward. By supporting the indenter 121 of , it is possible to convert the stress based on the local deformation amount of the container 11 .

The compressing means 12 is composed of a lower indenter 121 and an upper indenter 122, and is provided with a compressive force by the compressive force applying mechanism 13, so that the observation sample OS can be sandwiched while being compressed in the cavity of the container. It has a possible configuration. In addition, in such a compression means 12, the lower indenter 121 also functions as a mounting table for mounting the observation sample OS. In addition, the lower indenter 121 presses the observation sample OS by the reaction force of the stress applied from the upper indenter 122 , so that the observation sample OS can be compressed together with the upper indenter 122 .

As shown in FIGS. 4 and 5, the lower indenter 121 that constitutes the compression means 12 has a tip portion 121A that is a portion on the tip side that has a surface S1 that contacts the observation sample OS, and supports the tip portion 121A. It is composed of a support portion 121B which is a portion to hold. Note that the shape of the lower indenter 121 is such that a cylindrical protrusion P2 having a surface S1 (the surface of the tip portion 121A that is brought into contact with the observation sample OS) is replaced by a pedestal (a portion that serves as a pedestal for the protrusion) P3. A tip portion 121A is a portion of the protruding portion P2 on the tip side that is brought into contact with the observation sample OS. As described above, the tip portion 121A is a portion on the tip side of the indenter having the surface S1 that contacts the observation sample OS (the surface that is pressed during compression) (see FIG. 5). In this embodiment, the tip portion 121A has a columnar shape, and its top surface S1 and bottom surface (the surface in contact with the surface S2 of the support portion 121B) are both circular with the same diameter. Moreover, both the top surface S1 and the bottom surface of the tip portion 121A are planar.

Such a tip portion 121A exists on the path of the electromagnetic wave E, and the thickness and size are such that the portion (support portion 121B) other than the tip portion 121A of the indenter does not exist on the path of the electromagnetic wave E. etc. is designed. Since such a tip portion 121A exists on the traveling path of the electromagnetic wave E, the transmittance of the electromagnetic wave E used for the measurement is set to It is necessary to use one made of material that is 5% or more. If the transmittance is less than the lower limit, the transmitted image tends to be unclear. As a material for forming such a distal end portion 121A, a material having a transmittance of 5% or more for the electromagnetic wave E used for measurement may be appropriately selected and used. In addition, from the viewpoint of enabling more accurate measurement, the material constituting the tip portion 121A should have a transmittance of 40% or more (more preferably 60% or more) for the electromagnetic wave E used for measurement. , particularly preferably 80% or more). As the value of the transmittance of the electromagnetic wave E, a sample for transmittance measurement made of a material whose transmittance is to be measured It has an area sufficiently larger than the total area and the thickness is uniform), and the electromagnetic wave used for tilt CT measurement in the thickness direction of the sample (perpendicular to the surface) A value obtained by irradiating E and determining the transmittance of the electromagnetic wave E using a detector is adopted. The detector that can be used when obtaining the transmittance of the electromagnetic wave E can be appropriately selected and used according to the type of the electromagnetic wave E. For example, if the electromagnetic wave E is X-rays, an X-ray camera or the like is used. can.

The material constituting the tip portion 121A is not particularly limited as long as it has a transmittance of 5% or more for the electromagnetic wave E used for measurement. For example, polyetheretherketone (PEEK) , phenolic resin (Bakelite), aluminum nitride (AlN), silicon nitride, sapphire, etc., depending on the type of electromagnetic wave E used for measurement (for example, when the electromagnetic wave E is X-rays, the energy of X-rays, etc. depending on the material), a material whose transmittance of the electromagnetic wave E satisfies the above conditions can be appropriately selected and used. Moreover, such materials may be used singly or in combination of two or more.

In addition, the material that forms the tip portion 121A is a portion of the tip portion 121A that has a surface that contacts the observation sample OS, and is a portion that presses the observation sample OS when compressed. It preferably has mechanical strength that does not cause breakage. That is, the magnitude of the compressive force (compressive stress) that can be applied to the indenter 121 by the compressive force applying mechanism 13 changes depending on the magnitude of the compressive strength of the tip portion 121A of the indenter 121. Accordingly, it is preferable to appropriately select and use a material having a sufficient compressive strength that can apply the compressive force necessary for measurement. From this point of view, it is preferable to use the tip portion 121A having a compressive strength of about 100 to 300 MPa. In addition, from the viewpoint of achieving both transmittance and compressive strength, the tip portion 121A is selected from the group consisting of resins with high mechanical strength such as polyetheretherketone, and ceramics made of light elements such as aluminum nitride. It is particularly preferred that it consists of at least one material that is A method for measuring the compressive strength will be described later.

The diameter of the cylindrical upper surface (the surface to be brought into contact with the observation sample OS) S1 of the tip portion 121A of the indenter 121 is not particularly limited, and the design can be appropriately changed according to the type of the electromagnetic wave E and the purpose of measurement. can. For example, when the electromagnetic wave E is X-rays (synchrotron radiation X-rays) of about 15 keV to 30 keV, when measuring a general thin film sample of about 0.5 μm to 3 mm, the inside of the indenter From the viewpoint of the transmission distance of X-rays that pass through the upper surface S1, it is preferable to design the diameter of the upper surface S1 to be about 3 mm to 5 mm. If the diameter of the cylindrical upper surface S1 of the tip portion 121A of the indenter 121 is made smaller, the transmission distance of the electromagnetic wave E in the tip portion 121A can be shortened. If it is possible to perform CT measurement by reducing the area of the deformed part (if there is no problem even if the deformation mode is changed from uniaxial compression deformation), the diameter may be made smaller and the measurement may be performed. .

In addition, in order to perform a more accurate measurement, the tip portion 121A has a thickness of 5% or more based on the transmission distance of the electromagnetic wave E in the tip portion, etc., so that the transmittance of the electromagnetic wave E of the tip portion 121A itself is 5% or more. It is preferable to appropriately design such sizes and shapes.

Further, the supporting portion 121B of the indenter 121 is shaped so as not to enter the traveling path of the electromagnetic wave E. As shown in FIG. When the support portion 121B enters the travel path of the electromagnetic wave E, the transmittance of the electromagnetic wave E used for measurement is lowered, making it difficult to perform accurate measurement. From this point of view, it is preferable to design the support portion 121B into a shape that does not enter the traveling path of the electromagnetic wave E. The upper projecting portion of the contacting support portion 121B has a cylindrical shape, the intermediate portion has a truncated cone shape, and the lower portion (bottom side portion) has a cylindrical shape. In order to explain the shape of the support portion 121B, the upper, middle, and lower shapes are described, but the support portion 121B is integrally molded.

The support portion 121B of such an indenter 121 has a compressive strength of 100 MPa or more (more preferably a compressive strength of 100 to 300 MPa, more preferably 100 to 300 MPa) measured under a temperature condition of 23 ° C. in accordance with JIS K7181 (issued in 2011). is 150-300 MPa). If the compressive strength of such a material is less than the lower limit, the compressed area changes during compression, making it impossible to perform highly accurate measurements. Regarding such compressive strength, even if it exceeds the upper limit, there is no big problem, but it is preferably 300 MPa or less. In addition, in this specification, the compressive strength of a material adopts the value measured under temperature conditions of 23 degreeC based on JISK7181. That is, a prismatic, cylindrical or tubular measurement sample made of a material whose compressive strength is to be measured is prepared, and a compression test is performed on the measurement sample under a temperature condition of 23 ° C. The value obtained is adopted. can do. From the viewpoint of such compressive strength, the supporting portion 121B is more preferably made of at least one material selected from the group consisting of steel such as stainless steel and alloys.

Further, the lower indenter 121 is arranged so that the support portion 121B abuts on the bottom surface of the container 11 . The shape of the bottom surface S3 of the support portion 121B, which is in contact with the container 11, is circular, and the surface thereof is planar.

The area of the container contact surface (surface in contact with the container) S3 of the support portion 121B is 5 to 100 times as large as the area of the tip contact portion (region in contact with the tip portion) S2 of the support portion 121B. It should have a size (more preferably 8-10 times). If the ratio (magnification) of the area of the container contacting surface S3 to the area of the tip contacting portion S2 is less than the lower limit, a sufficiently high compressive force necessary for measurement from the viewpoint of the strength of the container 11 can be applied. cannot be given. That is, when a compressive force (compressive stress) is applied downward to the upper indenter 122 using the compressive force applying mechanism 13, the container 11 is also compressed downward from the contact surface S3 of the lower indenter 121A. A tensile stress of the same force as the force is applied. At this time, if the area of the contact surface S3 is small, it becomes difficult to sufficiently disperse the stress applied to the container, and the stress concentrates on a part of the container (the part in contact with the indenter). The container is likely to be destroyed at the portion where the indenter is installed. On the other hand, if the ratio (magnification) of the area of the container contacting surface S3 to the area of the tip contacting portion S2 exceeds the upper limit, the amount of deformation of the container 11 becomes very small with respect to the applied compressive stress. , When performing CT measurement while detecting the magnitude of compressive stress, it may be necessary to increase the stress detection sensitivity. This tends to increase the size of the jig.

As described above, in the present invention, in order to prevent breakage of the container 11 and apply a compressive force within a range necessary for measurement, the tip abutting portion with respect to the area of the container abutting surface S3 The ratio (magnification) of the area of S2 is set to 5 to 100 times (thereby, the stress applied to the container 11 from the container contact surface S3 of the support portion 121B is such that the container contact surface S3 is the area of the tip contact portion S2). 1/5 to 1/100 compared to the case where the area is the same), the stress is sufficiently dispersed and the breakage of the container 11 is sufficiently suppressed. Further, in the present invention, when CT measurement is performed while detecting the magnitude of the compressive stress, the area of the contact surface S3 with the container (housing) 11 of the support portion 121B is set to a range that does not impair the detection sensitivity of the stress. When the area of the contact surface S3 is increased in this way, it becomes possible to sufficiently disperse the tensile stress applied to the container 11 while detecting the stress with sufficient accuracy. , it is possible to reduce the stress load on the container (casing) and sufficiently suppress the breakage of the container 11 . Note that when the ratio (magnification) of the area of the tip contact portion S2 to the area of the container contact surface S3 is set to 8 to 10 times, the container contact surface S3 is the same as the area of the tip contact portion S2. The stress applied to the container 11 from the container contact surface S3 of the support portion 121B is about 1/8 to 1/10 compared to the case where the area is used. Even if the stress is applied from , the stress applied to the container 11 is considered to be about 37.5 MPa at maximum. Therefore, when the ratio (magnification) of the area of the tip contact portion S2 to the area of the container contact surface S3 is 8 to 10 times, the material of the container 11 is so-called engineering plastic (because it is a light element, it is basically high electromagnetic wave transmittance) can be preferably used. Thus, in the present invention, the support portion of the indenter on the side in contact with the inner surface of the container of the two indenters used is the ratio (magnification) of the area of the tip contact portion S2 to the area of the container contact surface S3. is 5 to 100 times, for example, a resin material with low strength but high X-ray transmittance (acrylic resin, etc.) can be used as appropriate for the container. It is also possible to carry out measurements.

Further, the diameter R3 of the container contacting surface S3 of the supporting portion 121B is not particularly limited, but is preferably about 10 to 50 mm. If the diameter R3 is less than the lower limit, the area of the container contact surface S3 becomes small, so that it becomes difficult to apply a sufficiently high compressive force when compressing the container 11 from the viewpoint of preventing breakage of the container 11. On the other hand, when the above upper limit is exceeded, the stress detection sensitivity tends to be low in the case of tilt CT measurement with low compressive stress.

In addition, in the present embodiment, the diameter R2 of the tip contact portion (area in contact with the tip portion) S2 of the support portion 121B is the diameter of the bottom surface side (surface side in contact with the support portion 121B) of the tip portion 121A. It has the same size as the diameter of the surface (in this embodiment, the tip 121A has a cylindrical shape, so it has the same diameter as the surface S1 of the tip 121A). Therefore, as a suitable example, the diameter R2 is about 3 mm to 5 mm, like the diameter of the surface S1 of the tip portion 121A.

Note that the lower indenter 121 is arranged and fixed on the protrusion P1 on the bottom surface of the container part 11 . The method of fixing the lower indenter 121 onto the protrusion P1 on the bottom surface of the container 11 is not particularly limited, and for example, it may be fixed with an adhesive or the like.

The upper indenter 122 that constitutes the compression means 12 is housed in the hollow portion of the container body 11, and the observation sample OS placed on the lower indenter 121 is placed between the lower indenter 121 and the observation sample OS. It allows compression. In the present embodiment, the upper indenter 122 is designed in the same manner as the lower indenter 121 in terms of shape and material.

Such an upper indenter 122 is composed of a tip portion 122A and a support portion 122B that supports the tip portion 122A. As such an upper indenter 122, basically the same one as the lower indenter 121 can be suitably used, except that the installation position is different. Therefore, as the tip portion 122A of the upper indenter 122, one that satisfies the same conditions as the tip portion 121A of the lower indenter 121 can be preferably used. The material of the tip portion 122A must be made of a material having a transmittance of 5% or more for the electromagnetic wave E used for measurement, like the tip portion 121A of the lower indenter. Also, as the supporting portion 122B of the upper indenter 122, one that satisfies the same conditions as the supporting portion 121B of the lower indenter 121 can be preferably used. The support part 122B, like the support part 121B of the lower indenter, must be made of a material having a compressive strength of 100 MPa or more measured under a temperature condition of 23° C. according to JIS K7181.

Further, the diameter of the surface of the tip 122A of the upper indenter 122 that contacts the observation sample OS is preferably the same size as the diameter of the surface of the tip 121A of the lower indenter 121 that contacts the observation sample OS. . With such a diameter, the same central region of the observation sample OS can be sandwiched between the upper indenter 122 and the lower indenter 121 and compressed efficiently. After the observation sample OS is placed on the lower indenter 121 in this manner, the observation sample OS is compressed and sandwiched by the lower indenter 121 and the upper indenter 122, whereby the observation sample OS is compressed. It is possible to perform measurement by the tilt CT method while applying a compressive force to the specimen. The compression force applied to the observation sample OS is applied to the compression means 12 by the compression force application mechanism 13, which will be described later. In addition, the upper indenter 122 is arranged so that it can apply pressure (press pressure) toward the lower indenter 121 when it receives a compressive force from the compressive force applying mechanism 13 . . Such an upper indenter 122 is only required to be in a state capable of applying pressure (press pressure) to the observation sample OS as described above, and its arrangement method and the like are not particularly limited. It may be fixed by adhering to the applying mechanism 13 , or may be configured to receive the compressive force of the compressive applying mechanism 13 by separately using a guide, a centering jig, or the like.

The compressive force application mechanism 13 is not particularly limited as long as it is a structure capable of applying a compressive force to the compressing means 12. A structure having a known mechanism that enables the observation sample OS to be compressed between them can be used as appropriate. For example, the compressive force applying mechanism 13 may be composed of a so-called ball screw, and the compressive force may be applied downward (upper indenter 122) by tightening the screw with a rotary motor or the like. is composed only of a stress transmission portion (for example, a metal rod), and a compressive force may be applied to the upper indenter 122 connected to the stress transmission portion by a separate press machine or the like, or the stress transmission portion may be moved downward. A compressive force may be applied downward (upper indenter 122) by separately connecting a device for moving the . Also, the material of the compressive force applying mechanism 13 is not particularly limited, and the material and the like may be appropriately changed depending on the part in the compressive force applying mechanism 13 according to its structure. The compression force applying mechanism 13 is provided with a flange portion for connecting to the top plate of the container 11, and the flange portion is fixed to the top plate of the container 11 by a fixture 50 (for example, a screw). It is

The observation sample holding jig 10 of the embodiment shown in FIGS. 3 and 4 is fixed by a fixture 50 (for example, screws) to a cylindrical mounting member 20 for mounting on a rotating stage 30 of a so-called tilt CT apparatus. there is Since such a cylindrical mounting member 20 exists on the transmission path of the electromagnetic wave E, from the viewpoint of the transmittance of the electromagnetic wave E, one made of a resin material can be preferably used. Moreover, such a mounting member 20 can preferably utilize a cylindrical member having a space inside. When the observation sample holding jig 10 is mounted on the rotating stage 30 via the mounting member 20 which is a cylindrical member made of such a resin material and having a space inside, the transmission path of the electromagnetic wave E in laminography CT is Even if the mounting member 20 is present in the wall, the member 20 itself does not significantly hinder the transmission of electromagnetic waves, so non-destructive three-dimensional measurement by laminography CT can be performed with high accuracy. Although the outer diameter R4 of the mounting member 20 is not particularly limited, it is preferably about 30 to 100 mm from the viewpoint of preventing deflection around the sample during rotation.

Further, as shown in FIG. 3, the observation sample holding jig 10 of the present embodiment is installed on a rotating stage 30 via a mounting member 20 . By rotationally driving the rotary stage 30 as described above, the observation sample holding jig 10 can be rotated around the rotation axis C, and CT measurement is performed in a state where the observation portion of the observation sample OS is rotated by 360°. becomes possible. As described above, the observation sample holding jig 10 for tilt CT is attached to the rotation stage 30 via the attachment member 20 (preferably resin-made attachment member 20) having a space inside. While applying a compressive force to the sample and rotating the sample, the tilt CT method makes it possible to perform non-destructive three-dimensional measurement of the internal structure of the observation sample OS. As such a rotary stage 30, a known stage that can be rotationally driven and used in a CT apparatus or an oblique CT apparatus can be appropriately used.

Here, the observation sample holding jig 10 of the embodiment shown in FIGS. accommodate. Then, the compressive force applying mechanism 13 applies a compressive force to the upper indenter 122 to sandwich the observation sample OS between the lower indenter 121 and the upper upper indenter 122 . By sandwiching the observation sample OS in this way, the observation sample OS sandwiched between the upper structural portion 122A of the protruding portion of the upper indenter 122 and the upper structural portion 121A of the protruding portion of the lower indenter 121 can be observed. A region of the sample OS can be in a compressed state. Therefore, when such an observation sample holding jig 10 is used, non-destructive three-dimensional measurement of the internal structure of a compressed observation sample can be performed with higher accuracy. It is possible to understand in detail the behavior of the sample under compression by performing tilt CT measurement of the internal structure of the sample under compression.

When tilt CT is performed using such an observation sample holding jig 10, an apparatus having the same configuration as a known tilt CT apparatus (oblique CT apparatus) except for using the observation sample holding jig 10 is appropriately used. Measurements can be made using A CT apparatus used for tilt CT using the observation sample holding jig 10 includes a source (radiation source) of the electromagnetic wave E, a detector for detecting the electromagnetic wave E, and an observation sample holding jig. and are arranged so that the rotation axis C and the traveling direction of the electromagnetic wave (irradiation axis connecting the radiation source and the center of the detector) obliquely intersect can. Thus, in the tilt CT apparatus used for measurement, the source (radiation source) of the electromagnetic wave E, the detection The container and the observation sample holding jig 10 may be arranged, and by using this, it becomes possible to efficiently perform laminography CT on the observation sample OS in a compressed state.

Furthermore, although the observation sample OS to be measured by the tilt CT is not particularly limited, it is preferable to target a sample whose internal structure or the like does not change during the measurement time. Further, the shape of the observation sample OS for such an oblique CT is not particularly limited, but the observation sample holding jig 10 has a flat plate shape (thin film, sheet, etc.) that is difficult to measure in normal CT measurement. Observation specimens can be compressed and deformed for tilt CT measurement. A sample can be conveniently used. In the case of an observation sample OS having a large thickness (in a direction parallel to the compression direction), CT measurement can be performed by simply tilting the CT apparatus so that the tip of the indenter holding the observation sample does not interfere with the path of the electromagnetic wave E. However, in this case, the transmission distance of the electromagnetic wave E in the sample becomes long, and the transmittance of the electromagnetic wave E tends to decrease. Therefore, the observation sample OS should be thinner. It is preferable to From this point of view as well, it is preferable to use a flat plate-like (thin-film, sheet-like, etc.) observation sample OS, which is difficult to measure in a normal CT measurement, as a measurement target. Although the thickness of the observation sample OS (in the direction parallel to the compression direction) is not particularly limited, it is set to 10 μm to 3 mm because it enables more accurate measurement in tilt CT measurement. is preferred.

Further, when tilt CT is performed using the observation sample holding jig 10, the angle (the tilt of the tilt CT angle) is more preferably 15° to 75°, even more preferably 25° to 45°. If the angle formed by the axis of rotation C and the traveling direction of the electromagnetic wave E is less than the lower limit, the transmission distance of the electromagnetic wave E in the sample becomes long, and the clarity of the reconstructed image obtained tends to decrease. On the other hand, when the upper limit is exceeded, the amount of angular correction of the transmitted image used for reconstruction increases, and noise in the reconstructed image tends to increase. In order to set the angle formed by the rotation axis C and the traveling direction of the electromagnetic wave E within the above range, the rotation axis C is tilted to the above angle (15° to 75°) with respect to the vertical direction ( Posture), the observation sample holding jig 10 may be installed on the rotating stage 30 via the mounting member 20 . Thus, the observation sample holding jig 10 is preferably used for CT measurement in which the tilt angle of the tilted CT is the above angle (15° to 75°). In addition, in order to obtain such an inclination angle, when measuring, the rotation axis C is inclined 15 to 75 degrees with respect to the ground surface (horizontal plane) so that the traveling direction of the electromagnetic wave E is parallel to the horizontal plane. It is preferred to perform oblique CT measurements.

Further, the source (radiation source) of the electromagnetic wave E is not particularly limited, and a known radiation source can be appropriately used according to the type of the electromagnetic wave E used for measurement. can appropriately utilize a known X-ray generator (eg, X-ray tube, etc.). In addition, the electromagnetic wave detector is not particularly limited, and a known detector can be appropriately used according to the type of electromagnetic wave. For example, when X-rays are used as the electromagnetic wave E, a known X-ray detector is appropriately used. can do. Other configurations of the tilt CT apparatus are not particularly limited, and those of known CT apparatuses can be used as appropriate.

In this way, for example, using an X-ray generator and an X-ray detector, the traveling direction of X-rays (electromagnetic waves E) (the axis connecting the centers of the X-ray generator and the X-ray detector) and the above When the X-ray generator, the X-ray detector, and the observation sample holding jig 10 are arranged so that the rotation axis C obliquely intersects, the rotation axis It is possible to perform X-ray CT measurement in a state in which the observation portion of the observation sample OS is rotated 360° around C. When the observation sample holding jig 10 of the present embodiment is used in this manner, for example, by X-ray laminography CT, X-rays are transmitted through the observation sample OS in a compressed state, and the observation sample OS is compressed. It is also possible to accurately perform non-destructive three-dimensional measurement of the OS.

The preferred embodiments of the observation sample holding jig for tilt CT according to the present invention have been described above with reference to FIGS. It is not limited.

For example, in the above-described embodiment, the side surface of the container on the bottom side is formed obliquely with respect to the rotation axis C, but in the observation sample holding jig for inclined CT of the present invention, the shape of the container is not particularly limited. Instead, a container having a shape in which all sides of the container are parallel to the rotation axis C may be used. In the measurement by the tilt CT method, it is preferable to rotate the observation sample OS by 360° in order to obtain a more accurate transmission image. It is more preferable that each member including the container in (1) is rotationally symmetrical with respect to the rotation axis (C). In the above-described embodiment, as described above, the container 11 is composed of the upper structure including the top plate and part of the side walls and the lower structure including the bottom part and part of the side walls. However, in the observation sample holding jig for tilt CT of the present invention, the configuration (structure) of the container 11 is not particularly limited. A plate may be used as the container 11 .

In the above embodiment, the lower indenter 121 and the upper indenter 122 have the same shape as described above, but in the present invention, the two indenters may have different shapes. Well, for example, the size of the contact surface (contact portion of the support portion) of the upper indenter 122 with the compression force imparting mechanism 13 is a big problem regardless of the ratio to the area of the portion that contacts the tip portion. Therefore, both the tip portion and the support portion of the upper indenter 122 may be cylindrical.

Further, in the above-described embodiment, in the lower indenter 121 and the upper indenter 122, the distal end portions (121A, 122A) of the projecting portion P2 are used as the distal end portions (121A, 122A). The size and shape are not particularly limited, and for example, a material having a transmittance of 5% or more for the electromagnetic wave used for measurement with the entire cylindrical protrusion P2 as the tip portion 121A according to the traveling path of the electromagnetic wave E. The size, shape, and the like may be changed as appropriate, such as by Note that when the entire columnar protrusion P2 is the tip portion 121A, the area of the contact area between the portion P3 that serves as the pedestal and the columnar protrusion P2 is the "area of the contact portion of the tip portion of the support portion. ”.

Further, in the above embodiment, the upper indenter 122 is directly connected to the compressive force applying mechanism 13, but in the present invention, for example, the observation sample OS can be compressed and held by two indenters. Moreover, if at least one of the two indenters is arranged so that the support portion abuts on any part of the inner surface of the container, the method of arranging the upper indenter 122, the structure of the container, etc. Without limitation, for example, a container composed of a cylindrical container body and a top plate having the same size as the inner diameter of the opening of the container body, and configured so that the top plate can move up and down in the cavity of the container. is used to fix and arrange the upper indenter 122 on the surface of the top plate of the container so that the support portion abuts, and the lower indenter 121 is placed on the bottom surface of the container body so that the support portion abuts. , and then the compressive force applying mechanism 13 is connected to the top plate of the container to apply a compressive force and move the top plate downward, resulting in the lower indenter 121 and the upper indenter 122 may be configured to apply a compressive force. When such a configuration is adopted, both of the two indenters are arranged so that the support portions are in contact with the inner surfaces (the top surface and the bottom surface) of the container 11 .

Furthermore, in the above embodiment, the stress is applied by moving the upper indenter downward. , and may be turned upside down to move the lower indenter upward. Further, in the case of using the observation sample holding jig for tilt CT according to the above-described embodiment, for example, the minute deformation of the container 11 is used to convert the stress value, and the tilt CT measurement is performed while measuring the compressive stress. It is also possible to In the case of performing CT measurement while measuring compressive stress using the observation sample holding jig for inclined CT of the present invention, the method of detecting compressive stress is not particularly limited. good.

As described above, the observation sample holding jig for tilt CT according to the present invention includes a container 11 having a hollow portion for containing the observation sample OS, and two indenters that compress the observation sample OS in the hollow portion of the container 11. Each of the two indenters is made of a material having a transmittance of 5% or more for the electromagnetic wave used for measurement, and has a surface to be brought into contact with the observation sample. and a support portion that is a portion that supports the tip portion and is made of a material having a compressive strength of 100 MPa or more measured under a temperature condition of 23 ° C. in accordance with JIS K7181, and the two indenters at least one of which is arranged so that the support portion abuts on any part of the inner surface of the container, and the area of the container contact surface of the support portion is the tip portion contact of the support portion Any other configuration is not particularly limited as long as it satisfies the condition that it has a size 5 to 100 times larger than the area of the portion. The present inventors speculate as follows about the reason why the observation sample holding jig for tilt CT according to the present invention achieves the above object.

That is, first, in general, when a measurement technique such as tilt CT (laminography CT: see FIG. 2) is employed, electromagnetic waves such as X-rays are obliquely incident on an object. Therefore, for example, the observation sample holding jig used in normal CT (see FIG. 1: a measurement method in which an electromagnetic wave is vertically incident on an object) is used as it is as an observation sample holding jig for laminography CT. In this case, it becomes difficult to transmit electromagnetic waves (such as X-rays). On the other hand, in the present invention, since the observation sample is held in the container by an indenter having a tip made of a material having an electromagnetic wave transmittance of 5% or more, the electromagnetic wave is applied to the compressing means holding the observation sample. Even in the case of transmission, it is possible to perform measurement by compressing an observation sample while sufficiently suppressing a decrease in transmittance of electromagnetic waves. As described above, if the holding jig for the observation sample used in ordinary CT is used as it is for a measurement method such as tilt CT (laminography CT: see FIG. 2), the transmittance of the electromagnetic wave as a whole decreases. However, in the present invention, the tip of the indenter is made of a material that has a transmittance of 5% or more for electromagnetic waves. The inventors surmise that it is possible to obtain a good image.

In addition, when CT measurement is performed on a compressed observation sample, stress is applied to the connection surface between the indenter and the container. In the present invention, an indenter having a support portion that is arranged to contact the inner surface of the container is arranged such that the area of the container contact surface of the support portion is 5 to 100 times as large as the area of the tip contact portion of the support portion. By having a large size, it is possible to widely disperse the pressure applied to the bottom surface of the container, thereby reducing the stress load on the container (casing) and sufficiently preventing damage to the container. ing. Furthermore, in the present invention, all the support parts of the indenter are made of a material having a compressive strength of 100 MPa or more, which makes it possible to perform highly accurate measurement by the tilt CT method with a high compressive force. The inventors presume that Therefore, in the present invention, it is possible to increase the transmittance of the electromagnetic wave to be measured while compressing the observation sample with a sufficiently high compressive force by using two indenters. It is also possible to achieve both strength. Thus, according to the present invention, the observation specimen can be compressed with a sufficiently high compressive force, and the observation specimen in the compressed state can be measured by the tilt CT method with high accuracy. The present inventors infer that.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to perform measurement by the tilt CT method while applying a sufficiently high compressive force to the observation sample, and to obtain the internal structure of the observation sample in a compressed state. It is possible to provide an observation sample holding jig for tilt CT that enables non-destructive three-dimensional measurement to be performed with higher accuracy. Therefore, the observation sample holding jig for tilt CT of the present invention holds an observation sample when performing tilt CT measurement on a flat plate-shaped or film-shaped observation sample, which is difficult to be measured by normal CT. It is useful as a jig or the like for

REFERENCE SIGNS LIST 10 Observation sample holding jig for inclined CT 11 Container 12 Compression means 121 Lower indenter 121A Tip of lower indenter 121B Lower indenter support 122 Upper indenter 122A... Tip of upper indenter 122B... Supporting part of upper indenter 13... Compressive force imparting mechanism 20... Mounting member 30... Rotating stage 50... Fixture E... Electromagnetic wave C... Rotation axis, OS... sample to be observed, S... screen, I... image, P1... projecting part of bottom surface of container, P2... projecting part of indenter, P3... supporting part (portion serving as base) of projecting part of indenter, S1... The surface of the tip that comes into contact with the observation surface, S2: the contacting portion of the tip of the lower indenter (the area where the tip is in contact), S3: the container contacting surface of the lower indenter, and T: the side wall of the container. Thickness, R1: Outer diameter of the container, R2: Diameter of the tip contact portion S2, R3: Diameter of the surface S3, R4: Outer diameter of the mounting member.

Claims (3)

An observation sample holding jig used for measurement by a tilt CT method using electromagnetic waves,
A container having a cavity for containing an observation sample, and compression means for compressing and sandwiching the observation sample in the cavity of the container with two indenters,
Each of the two indenters is made of a material having a transmittance of 5% or more for the electromagnetic wave used for measurement, and has a tip end portion having a surface to be brought into contact with the observation sample, and a temperature condition of 23 ° C. in accordance with JIS K7181. and a support portion that is a portion that supports the tip portion and is made of a material having a compressive strength of 100 MPa or more as measured in
At least one of the two indenters is arranged so that the support portion abuts on any portion of the inner surface of the container, and the area of the container contact surface of the support portion is equal to that of the support portion. Having a size 5 to 100 times larger than the area of the tip contact portion,
An observation sample holding jig for tilt CT, characterized by: In the indenter arranged so that the support portion abuts on any portion of the inner surface of the container, the area of the container contact surface of the support portion is larger than the area of the tip contact portion of the support portion. 2. An observation sample holding jig for oblique CT according to claim 1, which is eight to ten times as large. 3. An observation sample holding jig for inclined CT according to claim 1, wherein said supporting portion is made of a material having said compressive strength of 100 MPa to 300 MPa.

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