JP2000055844A - Non-destructive inspection method utilizing nuclear magnetic resonance phenomenon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect the presence or absence of defect and deformation non- destructively by providing a plurality of markers where the content of an atom with a magnetic moment is controlled to a value that differs from that of an atom in a material to be inspected in advance and utilizing the nuclear magnetic resonance(NMR) phenomenon of the marker in inspection. SOLUTION: An atomic nucleus where the number of protons and that of neutrons are both even does not have any magnetic moment, and the others all have a magnetic moment. A natural carbon and carbon in a carbon compound have 12C and 13C. The atomic nucleus of 12C is an even-even nucleus and does not have any magnetic moment but 13C is an even-odd nucleus and has a magnetic moment. 13C is utilized by the NMR method. For example, a high-pressure container and a golf shaft utilizing a carbon fiber cause such defect as interlayer release and fiber rupture due to excessive shock and cause strength to decrease. A marker that is given in advance is inspected by the NMR to inspect the presence or absence and the degree of the defect. If any defect exists, the regularity of the pattern of the NMR image of the marker collapses for detecting the defect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to nuclear magnetic resonance (Nu).
clear Magnetic Resonance:
The present invention relates to a nondestructive inspection method using a phenomenon, which is appropriately abbreviated as “NMR” in the present specification, a nondestructive inspection marker (Marker) using an NMR phenomenon, and a nondestructive inspection object.

[0002]

2. Description of the Related Art For example, carbon fiber reinforced materials have the advantages of high strength and light weight, are used as structural materials for aircraft bodies, vehicle bodies, houses, bridges, and the like. It is also used for materials. However, due to fatigue or excessive impact due to long-term use, defects such as delamination and fiber breakage occur, and strength is reduced. In order to confirm the safety of use, it is desired to inspect these defects nondestructively. There is a high need for non-destructive inspection of structures even in cases other than carbon materials such as carbon fiber reinforced materials.
In recent years, the need for recycling to reduce environmental impact has increased, and the importance of nondestructive inspection has increased.

Conventional non-destructive inspection methods include (1) an ultrasonic method for examining the reflection intensity of an ultrasonic wave, (2) an eddy current flaw detection method for examining a magnetic field due to an eddy current, and (3) an X-ray for examining the transmission intensity of X-rays. Method, (4) thermography method for examining the emission intensity of infrared rays, (5) immersion in a defect and N
There is a submerged NMR method utilizing the MR phenomenon.

[0004] Among them, (1) the ultrasonic method is complicated in that it is necessary to apply water or the like to the surface of the object in order to perform acoustic matching with the object to be inspected. In this case, it is difficult to detect the break. (2) The eddy current flaw detection method is difficult to detect a defect with a thick inspection object, and cannot be used when the inspection object is an insulator. (3) The X-ray method cannot be inspected from one side, and is not suitable for inspecting a carbon material having high permeability, for example. (4) In the thermography method, it is necessary to heat the inspection object, the operation is complicated, and the S / N ratio is low. (5)
In the submerged NMR method, the boil operation for immersion is complicated,
The inspection takes a long time, and it is not possible to detect a defective portion into which water cannot enter, such as a sealed void.

In these methods, for example, CFRP
Both the resin portion (matrix portion) and the carbon fiber portion of (carbon fiber reinforced plastic) cannot be inspected with one inspection device, and there is no other method for inspecting with one device. For example, there is no method for selectively inspecting only a specific material in an inspection target in which a plurality of materials such as CFRP are combined.

[0006]

In the present invention, attention is first paid to the NMR method as a nondestructive inspection method, and this method is used. On the other hand, a material in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom in the constituent material of the inspection object is added as a marker. An object of the present invention is to provide a new and useful non-destructive inspection method utilizing both of them, a non-destructive inspection marker and an inspection object for that purpose.

[0007]

According to the present invention, (1) the content of atoms having a magnetic moment with respect to a test object is controlled to a value different from the content of the atoms in the material of the test object. A nuclear magnetic resonance phenomenon characterized in that one or more markers including at least one material are provided in advance, and a defect or deformation is inspected at the time of inspection by using a nuclear magnetic resonance image of the marker. Provide a non-destructive inspection method using

The present invention relates to (2) a marker for nondestructive inspection utilizing a nuclear magnetic resonance phenomenon, wherein the content of an atom having a magnetic moment is controlled to a value different from the content of the atom in an inspection object. The present invention provides a marker for nondestructive inspection utilizing a nuclear magnetic resonance phenomenon, characterized in that the marker is at least one kind of marker including at least one material.

The present invention relates to (3) a marker for nondestructive inspection utilizing a nuclear magnetic resonance phenomenon, wherein the content of an atom having a magnetic moment is determined by the content of the atom in a test object made of a fiber-reinforced material. Provided is a nondestructive inspection marker using a nuclear magnetic resonance phenomenon, which is one or two or more markers including at least one fiber controlled to different values.

The present invention relates to (4) a non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein the content of an atom having a magnetic moment with respect to the inspection object is determined by the content of the atom in the object. Provided is a non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein at least one kind of marker including at least one material controlled to a value different from the content is arranged.

According to the present invention, (5) a non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon is a conduit or a joint, and the content of atoms having a magnetic moment with respect to the conduit or the joint is determined by the conduit or the joint. Non-destructive inspection using a nuclear magnetic resonance phenomenon, wherein at least one kind of marker containing at least one material controlled to a value different from the content of the atom in the constituent material is arranged Provide the object.

The present invention relates to (6) a non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon made of a fiber reinforced material, wherein the content of atoms having a magnetic moment with respect to the inspection object is determined by the fiber reinforced material. One or two types including at least one fiber controlled to a value different from the content of the atom in the material object
Provided is a non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon characterized by arranging more than one kind of marker.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Containers, conduits, plates, rods and other various structures used in various applications are subject to peeling or breakage due to fatigue or excessive impact due to long-term use. Strength decreases. In the present invention, a nuclear magnetic resonance phenomenon is used as a nondestructive inspection method for various structures. Nuclear nuclei having even numbers of protons and neutrons do not have a magnetic moment, and all other nuclei have a magnetic moment. NMR detects a nucleus having the magnetic moment.

For example, natural carbon and carbon in carbon compounds
Is¹²C and¹³C is included. this house¹²The nucleus of C is
Even and even nuclei have no magnetic moment
Is¹³C has a magnetic moment. By NMR method
Is¹³C is measured and used. In the present invention,
Content of the atom that has ¹³
For test objects containing C at the natural isotope abundance,
With a content different from the natural isotope abundance¹³Material containing C
Used as a marker.

[0015] In the present invention, the test object, which is a structure having various structures, is "at least one in which the content of atoms having a magnetic moment is controlled to a value different from the content of the atom in the material of the test object. One or more markers including "one material" are provided in advance. The “material in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom in the material of the inspection object” is not limited to one for the inspection object, and two or more are provided. be able to. When the inspection object is, for example, CFRP,
A ¹³ C different from the natural abundance ratio provided in advance in the carbon fiber portion may be provided as a marker, and ¹ H of the natural abundance ratio in the resin portion, that is, the matrix portion, may be used as a marker. It is a meaning including this.

According to the present invention, the presence or absence of a defect can be quickly detected by detecting those NMR images. As for the mode of the marker, the initial deformation and subsequent deformation are NM.
There is no particular limitation as long as it can be compared as a measurement result by R, but in order to be more effective, the marker arrangement pattern is preferably regular. If no defect has occurred since the time of application, a regular pattern of the NMR image of the marker is detected. If a defect has occurred, the regularity of the pattern of the NMR image of the marker is broken, and it is easy to have a defect there. Is detected.

As an atom having a magnetic moment,¹³C
Besides,¹H,^TwoH,^ThreeHe,⁷Li, ^TenB,¹¹B,¹⁴N,
^FifteenN,¹⁷O,¹⁹F,²⁷Al,²⁹Si,³¹P,³³S,⁴³C
a, ⁴⁵Sc,⁴⁷Ti,⁴⁹Ti,⁵¹V,⁵⁵Mn,⁵⁷Fe,
⁵⁹Co,⁶⁵Cu,⁷¹Ga,⁸⁷Rb,⁹³Nb,⁹⁵Mo,⁹⁷
Mo,¹¹³In,¹¹⁵In,¹²¹Sb,¹³⁵Ba,¹³⁷Ba,
¹⁴¹Pr,¹⁵¹Eu,¹⁶⁵Ho,¹⁷⁶Lu,¹⁸⁵Re,¹⁸⁷R
e,²⁰³Tl,²⁰⁵Tl,²⁰⁹Bi and the like. Book
In the present invention, the content of these atoms is referred to as the natural abundance.
Different materials are used as markers. These atoms
The material whose content is different from the natural abundance is 1
Two or more materials with different contents
You may.

Examples of marker materials include LiF, LiC
O_Three, LiOH, B, BN, C, SiO_Two, Al_TwoO_Three, S
c_TwoO_Three, VS, V_TwoO_Three, MnP, Mn_ThreeO_Four, MnC
O_Three, MnS, Fe_TwoO_Three, CoO, CoCO_Three, Co
_ThreeS_Four, CuO, Cu_TwoO, Cu_TwoS, CuBr, GaP,
GaAs, Ga_TwoO_Three, RbCIO_Four, NbO_Two, MoCl
_Two, MoCl_Three, In_TwoO_Three, InP, InSb, InA
s, Sb, Sb_TwoO_Three, InSb, Sb _TwoS_Three, EuSO_Four,
ReO_Two, Tl_TwoO_Three, TlI, Bi_TwoO_Three, Bi_TwoS_Three, D
Poxy resin, polyamide resin, polyimide resin, polye
Tylene and the like.

Among these materials, a material in which the content of atoms having a magnetic moment is controlled to a value different from the constituent materials of various structures is used as a marker. Markers are used for various structures, such as metals, semiconductors, glass, ceramics,
Containers and conduits (pipes and tubes, for example, polyethylene pipes, polyethylene fittings, etc.), plates and rods, and other various shapes made of polymer materials, solid organic matter such as oils and fats, composite materials and other materials Powder, whisker, layer,
It is provided as a linear or other appropriate shape.

In the case of a powder or a whisker, the material is evenly dispersed inside, on the surface, or throughout the inspection object. In the case of a layered structure, it is present with a uniform layer thickness inside or on the surface. For example, polyethylene and other plastic pipes are used for transporting gases and liquids, such as gas pipes and water pipes. Markers are previously dispersed or present in these pipes, and these are used at the time of inspection. Inspection using a magnetic resonance image makes it possible to know the presence and degree of a defect.

In the case of a fiber-reinforced material as an example of a linear shape, a part of the yarn is used as a marker yarn, or a powdery or whisker-like marker is mixed with a material impregnated into a specific fiber-reinforced material. It can be applied in a manner. FRP
(Fiber reinforced plastic) is one of the typical composite materials, which is a material reinforced by dispersing fibers in plastic.
In FRP, fibers such as carbon, glass, boron, silicon carbide, alumina, and steel are used as the inorganic reinforcing fibers, and fibers such as polyamide, polyester, or epoxy resin are used as the organic reinforcing fibers. Can be

According to the present invention, a marker is provided on the surface or inside of such an FRP material in which the content of atoms having a magnetic moment is controlled to a value different from the normal natural abundance of those structures. In advance, the NMR image of the marker is used at the time of inspection. Examples of markers in this case are carbon fibers,
Glass fiber, boron fiber, silicon carbide fiber, alumina fiber, steel fiber, aramid fiber, polyester fiber, epoxy resin fiber and the like can be mentioned. Specifically, these can be, for example, markers configured as in the following (1) to (14).

(1)¹³C from natural isotope abundance 1.1%
Highly contained carbon fiber. (2) ²⁹Si is a natural isotope
Glass fiber contained at a higher concentration than 4.67%.
(3) ¹⁷O concentration higher than natural isotope abundance 0.038%
Glass fiber contained in. (4) ^TenB is natural isotope abundance 1
Boron fiber contained at a concentration higher than 9.9%. (5)¹¹B
Was contained in a concentration higher than the natural isotope abundance 80.1%.
Boron fiber. (6)¹³C from natural isotope abundance 1.1%
Also contains silicon carbide at a high concentration. (7)²⁹Si
Carbide contained at a higher concentration than isotope abundance ratio 4.67%
fiber. (8)¹⁷O is more than natural isotope abundance 0.038%
Alumina fiber contained in high concentration. (9)¹³C is a natural isotope
Aramid fiber contained at a higher concentration than 1.1%.
(Ten)¹⁷O concentration higher than natural isotope abundance 0.038%
Aramid fiber contained in. (11)^FifteenN is the natural isotope abundance
Aramid fiber containing higher than 0.366%
The word¹⁴N is lower than 99.634% of natural isotope abundance
Aramid fiber contained in the concentration. (12)^TwoH is a natural isotope
Aramid fiber with a higher concentration than 0.015%
Wei. (13)¹³Higher concentration of C than natural isotope abundance 1.1%
Steel fiber contained in. (14)⁵⁷Fe is a natural isotope abundance 2.
Steel fiber containing higher than 2%.

FRP includes high-pressure containers, sports equipment such as golf shafts and tennis rackets, artificial biomaterials, aircraft structural materials, bicycle shafts, automobile shafts and bodies, hull structural materials, bridge reinforcing materials, building components, Electrodes such as turbine blades, wind turbine blades, flywheels, fuel cells and electric double layer capacitors, heating elements, radio wave absorbers used for PC structural materials, furnace wall materials such as high temperature furnaces and fusion reactors, and neutron absorption It is used for materials and other various uses.
The marker of the present invention is also effectively applied to FRP in these.

Of the FRPs, for example, CFRP is lightweight and
High strength, high moldability, and excellent corrosion resistance and durability
It is a composite material. As that marker, with a part of the strand
do it ¹³C at a concentration higher than the natural isotope abundance 1.1%
Place the carbon fiber that you have, or¹³C is a natural isotope
Carbon materials containing abundance higher than 1.1%
Apply in an appropriate manner such as mixing in the impregnating material for RP.
Can be given.

Carbon fibers are produced by heat-treating organic fibers such as rayon or polyacrylonitrile or fibers produced by spinning coal tar pitch or refined petroleum pitch in an inert gas and carbonizing them. Although any of these carbon fibers is used in the present invention, the content of ¹³ C (having a magnetic moment) as a part of the twisted yarn in the various structural materials as described above is determined in the material to be inspected. A material controlled to a value different from the content of the atom is arranged as a marker.

Examples of the carbon-made artificial biomaterial include artificial roots, hip joints for preventing fractures, and artificial heart valves (carbon fibers obtained by hardening carbon fibers with a binder such as glassy carbon).
Carbon composite materials), artificial bones (composite materials obtained by bonding glassy carbon spheres with plastic and sintering), and artificial tendons (made of carbon fiber) have been developed.
Inspection by X-rays is difficult because of good line transmittance. According to the present invention, a material containing ¹³ C at a content different from the natural abundance is used as a marker, and an artificial biomaterial in the body can be easily inspected nondestructively by using an NMR image of the marker. it can.

There are no particular limitations on the NMR apparatus that can be used in the present invention. For example, various NM apparatuses as shown in FIGS. 2 to 4 or FIG. 5 (Matsumasa Takahashi, “MRI Recent Advances”, page 9) described later.
R devices are available. As an example of the NMR apparatus shown in FIGS. 2 and 3, a uniform static magnetic field is applied to an inspection object, and an electromagnetic wave is generated by a transmission coil on the inspection object to which a nondestructive inspection marker is attached in advance. For a short time. The electromagnetic waves are irradiated at right angles or almost at right angles to the static magnetic field.

After cutting off the electromagnetic wave from the transmitting coil, the receiving coil receives the electromagnetic wave emitted from the inspection object with the nondestructive inspection marker. Since the magnitude of the magnetic field varies depending on the position, the resonance frequency also varies depending on the position, and imaging becomes possible. A received signal corresponding to a previously applied marker is detected to determine whether or not a defect has occurred and its degree. N
The entire inspection object can be inspected by moving the MR apparatus relative to the inspection object, and the surface of the inspection object is not limited to a flat surface, but is also applied to a curved surface or the like.

According to the present invention, each material constituting the inspection object is selected by performing NMR measurement in accordance with each resonance frequency of a plurality of types of atoms (corresponding to markers) included in the inspection object. Inspection can be performed by one NMR apparatus. In this case, the transmission may be performed from a plurality of transmission coils arranged corresponding to the respective resonance frequencies, or the electromagnetic waves of the respective resonance frequencies may be transmitted at an interval from one transmission coil.

When the magnetic flux density of the static magnetic field applied to the inspection object is fixed, the resonance frequency of nuclear magnetic resonance differs depending on the type of atom. For example, when a static magnetic field having a magnetic flux density of 1.0 T is applied to an inspection target by an NMR apparatus, the resonance frequency of an atom in a marker provided in the target is 4 at ¹ H.
2.6 MHz, 10.7 MHz for ¹³ C, 1 for ³¹ P
7.2 MHz. The transmission frequency from one transmission coil is shifted by 10.7 MHz, 17.2
MHz and 42.6 MHz, and by receiving the corresponding NMR signals, the marker in the marker can be read.
¹³ C, ³¹ P, and ¹ H can be inspected by one NMR apparatus.

As an embodiment of performing NMR measurement on a plurality of types of atoms, for example, when CFRP is to be inspected, ¹
By inspecting H, resin part (matrix part)
And it is possible to inspect the carbon fiber parts by examining the ^{1 3} C. In addition, as a probe of the NMR apparatus,
For a large or medium-sized structure, use a one-sided detection type NMR apparatus using a permanent magnet as shown in FIG. 2, and for a sheet or small-sized structure, use a permanent magnet as shown in FIG. It can be properly used, for example, by using a sandwich type NMR apparatus.

The inspection results obtained by these NMR apparatuses are CT images (Computed Tomography Imag).
It is advantageous to determine according to e). A CT image can be obtained by a conventionally known operation. That is, NMR-CT
Then, as shown in FIG. 5, for example, a human body is placed in a strong static magnetic field, a high-frequency magnetic field is instantaneously applied, and immediately thereafter, CT is applied to electromagnetic waves radiated by NMR of atoms such as ¹ H and ³¹ P contained in the human body. The image of the cross section of the human body can be obtained by the method described above. Similarly, an NMR image can be obtained for the inspection object of the present invention. FIG. 6 schematically shows a case where an inspection result of an inspection object such as a high-pressure container or a conduit is displayed as a CT image.

[0034]

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but it goes without saying that the present invention is not limited to these examples.

Embodiment 1 FIG. 1A shows an example in which a marker is attached to the plate-like body 1. The content of the atom having a magnetic moment is defined as the content of the atom in the plate-like material. This is an example in which materials controlled to different values are provided in parallel as linear markers 2. FIG. 1 (b) shows a cylindrical portion 3 of a high-pressure container made of CFRP.
The marker of carbon fiber material in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom of the carbon fiber constituting the high-pressure vessel 3 in a mesh shape. This is an example.

The atom has a magnetic moment in the conventional carbon: ¹³ C is contained about 1.1 percent, since the measurement sensitivity of NMR and ¹³ C is less weak, is preferably from ¹³ C content Use markers controlled to be greater than about 1.1%. FIG. 1C shows a case where a marker is attached to the plate-like body 1, and a material in which the content of atoms having a magnetic moment is controlled to a value different from the content of the atoms in the plate-like material is used. This is a case where the powdery marker 5 is uniformly applied on the entire surface and inside of the plate-shaped material. FIG. 1D shows an example in which a linear marker 2 and a powder marker 5 are attached to a plate-like body 1.

For example, in a high-pressure container or a golf shaft using carbon fibers, the strength is reduced when defects such as delamination or fiber breakage occur due to excessive impact or the like. According to the present invention,
By inspecting the marker previously assigned as described above with the NMR apparatus, it is possible to detect the presence or absence of these defects and the extent of the presence or absence of the defects. If no defect has occurred, a regular pattern of the NMR image of the marker is detected. If a defect has occurred, the regularity of the pattern of the NMR image of the marker is broken, and it is detected that a defect has occurred there.

<Embodiment 2> FIG. 2 is a diagram showing an example of inspection of a thick plate-like object on which an object to be inspected is previously provided with a marker 6 in a layer shape by an NMR apparatus. In the NMR apparatus of the present embodiment, a uniform static magnetic field is applied to the inspection object by the permanent magnet 8, and the electromagnetic wave is generated by the transmission coil 9 on the inspection object 7 to which the nondestructive inspection marker 6 is attached in advance. For a short time. After cutting off the electromagnetic wave from the transmitting coil 9, the receiving coil 10 receives the electromagnetic wave emitted from the inspection object with the marker.
Transmission and reception can be performed by one coil. FIG. 2B shows an example in which three transmitting coils 9 are provided corresponding to the number of types of atoms included in the marker. NM that transmits and receives electromagnetic waves of different frequencies from each transmitting coil
By decomposing the R signal for each frequency by Fourier transform and performing signal processing, a single NMR apparatus can inspect a plurality of types of markers.

In the case of this example, since the magnitude of the magnetic field varies depending on the position, the resonance frequency also varies depending on the position, and imaging becomes possible. A received signal corresponding to a previously applied marker is detected to determine whether or not a defect has occurred and its degree. By moving the NMR apparatus relatively to the inspection object, the entire inspection object can be inspected. This example is also applied to the case where the surface of the inspection object is not limited to a flat surface but is a curved surface or the like. These detection and determination results can be displayed as a CT image in the same manner as in Example 5 (FIG. 5) described later.

<Embodiment 3> FIG. 3 is a diagram showing an example of inspection in the case where the inspection object by the NMR apparatus is a sheet-like body on which markers are previously applied in layers. In the NMR apparatus of this example,
The inspection object is sandwiched between the N pole and the S pole of the permanent magnet 8, a uniform static magnetic field is applied to the inspection object by the permanent magnet 8, and the inspection object to which the nondestructive inspection marker 6 is attached in advance. Thing 7
Is irradiated with electromagnetic waves for a short time by the transmission coil 9.
Otherwise, the presence / absence of a defect and the degree thereof are determined in the same manner as in the second embodiment. FIG. 3B shows an example in which three transmitting coils 9 are provided corresponding to the number of types of atoms included in the marker.

<Embodiment 4> FIG. 4B is a diagram showing an example of the arrangement of receiving coils in an NMR apparatus. In FIG. 4, each square indicates each receiving coil, and an arrow (↓) indicates a positional correspondence with the inspection object surface. FIG. 4A is FIG.
This is an example in which one receiving coil is arranged in the same manner as in FIG. 3, but by arranging a plurality of receiving coils in a plane parallel to the inspection object surface as shown in FIG. By detecting the signal in the receiving area of each coil with high accuracy and displaying the detection result two-dimensionally based on the signal obtained by each receiving coil, the inspection can be performed with high spatial resolution.

<Embodiment 5> FIG. 5 shows a case where the present invention is applied to a human body.
It is a figure which shows the example of a test | inspection by the NMR apparatus of the artificial heart valve (carbon / carbon composite material which hardened carbon fiber with binders, such as glassy carbon, etc.) which gave the marker beforehand. As an operation, the excitation power supply is driven, and a uniform static magnetic field is applied by the electromagnet 11 in the axial direction of the cylinder. Further, the linear magnetic field gradient generator is driven, and a gradient magnetic field is applied using the magnetic field gradient coil 12 so that the magnitude of the static magnetic field in the axial direction changes in proportion to the position coordinates. The high-frequency pulse generator is driven to irradiate the electromagnetic wave through the irradiation coil 13 for a short time.

After the electromagnetic wave from the irradiation coil 13 is cut off,
An electromagnetic wave emitted from an artificial heart valve in the human body is received by the receiving coil 14. The amplified signal is subjected to frequency analysis by a calculation / processing unit to extract a signal necessary for imaging. Since the magnitude of the magnetic field in the axial direction differs depending on the position, the resonance frequency at each position differs, and the position of the emitted signal can be calculated backward by separating the detection signal according to the frequency. The display / recording unit creates and outputs a video based on the extracted signal. Also save the necessary data.

<Embodiment 6> FIG. 6 shows that the object to be inspected is FIG.
This is an example in which an inspection result is displayed as a CT image in an example of a high-pressure container as shown in FIG. FIG. 6 shows, in addition to the probe, an accessory device (including an amplifier, a receiver, an A / D converter, an arithmetic / processor) and a control / display device. The probe shown in FIG. 2 is used. FIG. 7 shows NMR spectra for a case where no defect has occurred and a case where a defect has occurred in the inspection object to which markers have been previously meshed.
FIG. 6 is a diagram illustrating an example of how a CT image appears. FIG. 7A shows a case in which no defect has occurred, and a mesh pattern that is regularly applied in advance is displayed as it is as an NMR image. FIG.
(B) shows a case where a defect has occurred. As shown in the center, the regularity of the mesh pattern is broken, and it is detected that a defect has occurred there. This example can be similarly applied to a case where the inspection object is a conduit or the like.

<Embodiment 7> FIG. 8 shows an example in which an inspection result is displayed as a CT image using an NMR apparatus in which a plurality of probes are arranged in a direction parallel to the surface of the inspection object. A plurality of probes are provided in a direction parallel to the surface of the inspection object, and a detection signal from each probe is reconstructed by signal processing to display a two-dimensional inspection result. As a result, the inspection area for one inspection can be enlarged, and the inspection time for an inspection object having a large area can be reduced.

[0046]

According to the present invention, the following effects (1) to (5) can be obtained in addition to the effects described above. (1) Nondestructive inspection of insulators and the like can be performed. (2) Fine defects can be detected. (3) The defect location can be easily found as a regular pattern deformation of the marker image by NMR imaging. (4) Inspection can be performed in a completely non-destructive state, and at the time of inspection, submerged NMR
Inspection can be performed quickly because there is no need to perform immersion treatment or the like as in the method. (5) The present invention can be applied not only to the inspection of the inspection object for defects after a certain period of use but also to the inspection of the defects after production and before the use.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example in which a marker according to the present invention is previously attached to a plate-like body or a high-pressure container.

FIG. 2 is a diagram showing an example of an NMR apparatus and an example of inspection of a plate-like object on which an inspection target is provided with a marker in a layer form in advance by the NMR apparatus.

FIG. 3 is a diagram illustrating an example of an NMR apparatus and an inspection example in the case where an inspection target by the NMR apparatus is a sheet-like body in which markers are applied in layers in advance.

FIG. 4 is a diagram showing an example of arrangement of receiving coils in an NMR apparatus.

FIG. 5 is a diagram showing an example of an NMR apparatus and an example of obtaining a CT image by inspecting with the NMR apparatus.

FIG. 6 is a diagram showing an example of obtaining a CT image by inspecting with an NMR apparatus.

FIG. 7 shows N in the case where no defect has occurred in the inspection object to which markers have been previously meshed and in the case where a defect has occurred.
The figure which shows the example of how the MR image appears.

FIG. 8 is a diagram showing an example of obtaining a CT image by inspecting with an NMR apparatus.

[Explanation of Signs] 1 Plate-like body 2 Parallel marker 3 Cylindrical part of high-pressure vessel 4 Mesh-like marker 5 Powder-like marker 6 Layer-like marker 7 Inspection object 8 Permanent magnet 9 Transmitting coil 10 Receiving coil 11 Electromagnet 12 Magnetic field gradient coil 13 Irradiation coil 14 Receiving coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsumi Sakanaka 3-3-2 Shiomidai, Isogo-ku, Yokohama-shi, Kanagawa Prefecture 3303 Isogo Apartment Building 312 (72) Inventor Atsushi Fukuoka 4-1-13 Nakameguro, Meguro-ku, Tokyo 21 Urban Heights Nakameguro B307 (72) Inventor Tokudai Neda 4-13-21 Nakameguro, Meguro-ku, Tokyo Urban Heights Nakameguro B306

Claims (19)

[Claims] At least one material containing at least one material whose content ratio of atoms having a magnetic moment with respect to a test object is controlled to a value different from the content ratio of the atoms in the material of the test object. A non-destructive inspection method using a nuclear magnetic resonance phenomenon, wherein the above-described markers are provided in advance, and at the time of inspection, the presence or absence of a defect or deformation is inspected using a nuclear magnetic resonance image of the marker. 2. The test object is a test object composed of carbon having a ¹³ C content of natural isotope or a material containing carbon, wherein the marker has a ¹³ C content of natural isotope. The nondestructive inspection method utilizing nuclear magnetic resonance according to claim 1, wherein the marker is made of carbon or a material containing carbon controlled to a value different from the abundance. 3. The test object is a test object composed of a fiber reinforced material having a content of atoms having a magnetic moment having a natural isotope abundance, and the marker is a content of atoms having a magnetic moment. The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to claim 1, wherein the marker is a marker made of a fiber material in which is controlled to a value different from the natural isotope abundance ratio of the inspection object. 4. The fiber to be inspected is a carbon fiber, glass fiber, boron fiber, silicon carbide fiber, alumina fiber, steel fiber, aramid fiber or polyester fiber.
A nondestructive inspection method using the nuclear magnetic resonance phenomenon described in 1. 5. An inspection for inspecting the presence or absence of a defect or deformation using the nuclear magnetic resonance image of the marker at the time of the inspection is performed by one N
The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to claim 1, wherein the method is performed by an MR apparatus. 6. An inspection for inspecting the presence or absence of a defect or deformation by using a nuclear magnetic resonance image of the marker at the time of the inspection, a unit having one transmission coil for transmitting a plurality of electromagnetic waves by switching transmission frequencies. The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to any one of claims 1 to 4, wherein the non-destructive inspection method is performed by using an NMR apparatus. 7. An inspection for inspecting the presence or absence of a defect or a deformation using a nuclear magnetic resonance image of the marker at the time of the inspection is performed by a single NMR having a plurality of transmitting coils for transmitting electromagnetic waves of a plurality of types of frequencies. The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to any one of claims 1 to 4, wherein the method is performed by an apparatus. 8. An inspection for inspecting the presence or absence of a defect or deformation using a nuclear magnetic resonance image of the marker at the time of the inspection, wherein the inspection includes a plurality of receiving coils arranged on a plane parallel to a surface of the inspection object. The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to any one of claims 1 to 4, wherein the non-destructive inspection method is performed using one NMR apparatus. 9. An inspection for inspecting the presence or absence of a defect or deformation using a nuclear magnetic resonance image of the marker at the time of the inspection is performed by an NMR apparatus having a plurality of probes arranged in a direction parallel to a surface of the inspection object. The non-destructive inspection method using a nuclear magnetic resonance phenomenon according to claim 1, wherein the inspection is performed. 10. A marker for non-destructive inspection utilizing a nuclear magnetic resonance phenomenon, wherein at least one material in which the content of atoms having a magnetic moment is controlled to a value different from the content of said atoms in an inspection object. A non-destructive inspection marker utilizing nuclear magnetic resonance phenomena, wherein the marker is one or more types of markers including: 11. The material in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom in the test object controls the content of ¹³ C to a value different from the natural isotope abundance. The marker for nondestructive inspection utilizing nuclear magnetic resonance phenomenon according to claim 10, wherein the marker is carbon or a material containing carbon. 12. A marker for nondestructive inspection utilizing a nuclear magnetic resonance phenomenon, wherein the content of atoms having a magnetic moment is controlled to a value different from the content of said atoms in a fiber-reinforced material inspection object. A marker for nondestructive inspection utilizing nuclear magnetic resonance phenomena, wherein the marker is at least one kind of marker including at least one fiber. 13. A fiber in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom in the test object made of a fiber-reinforced material, is carbon fiber, glass fiber, boron fiber, silicon carbide fiber. The non-destructive inspection marker using a nuclear magnetic resonance phenomenon according to claim 12, wherein the marker is one of alumina fiber, steel fiber, aramid fiber and polyester fiber. 14. A fiber in which the content of the atom having the magnetic moment is controlled to a value different from the content of the atom in the test object made of a fiber-reinforced material, the content of ¹³ C is different from the content of natural isotopes. The non-destructive inspection marker using a nuclear magnetic resonance phenomenon according to claim 12, wherein the marker is a carbon fiber whose value is controlled. 15. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein a content of an atom having a magnetic moment with respect to the inspection object is different from a content of the atom in the object. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein at least one kind of marker including at least one material controlled in the above manner is arranged. 16. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon is a conduit or a joint, and the content of atoms having a magnetic moment with respect to the conduit or the joint is determined by the content of the constituent material of the conduit or the joint. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein at least one kind of marker including at least one material controlled to a value different from the atomic content is arranged. 17. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon made of a fiber reinforced material, wherein the content of atoms having a magnetic moment with respect to the inspection object is determined in the fiber reinforced material object. A non-destructive inspection object utilizing a nuclear magnetic resonance phenomenon, wherein at least one kind of marker including at least one fiber controlled to a value different from the content of the atom in the above is arranged. 18. The nuclear magnetic resonance according to claim 17, wherein the fiber of the object made of the fiber reinforced material is a carbon fiber, a glass fiber, a boron fiber, a silicon carbide fiber, an alumina fiber, a steel fiber, an aramid fiber or a polyester fiber. Non-destructive inspection object using phenomenon. 19. An object made of a fiber-reinforced material, comprising:
Sports equipment such as golf shafts and tennis rackets, artificial biomaterials, aircraft structural materials, bicycle shafts, automobile shafts and bodies, hull structural materials, bridge reinforcing materials, building components, turbine blades, windmill blades, flywheels The electrode according to claim 17, which is an electrode of a fuel cell or an electric double layer capacitor, a heating element, a radio wave absorbing material used for a structural material of a personal computer, a furnace wall material of a high temperature furnace or a fusion reactor, or a neutron absorbing material. Non-destructive inspection target using nuclear magnetic resonance phenomenon.