JPH0587646A - Measuring method for residual stress of ceramic member - Google Patents

Abstract

PURPOSE:To accurately measure the residual stress distribution of the fine part in the vicinity of the surface layer of a ceramic member in the depth direction thereof in a non-destructive manner. CONSTITUTION:A ceramic member 8 having a flat surface or a curved surface is irradiated with two or more kinds of X-rays different in penetration depth and a sin 2psi method is adapted to calculate the residual stress of the ceramic member from the obtained diffracted X-rays 9. From the calculated residual stress value and the respective penetration depths of X-rays, the residual stress gradient in the depth direction in the vicinity of the surface of the ceramics member 8 is calculated and the residual stress distribution of the ceramic member 8 in the depth direction is evaluated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring residual stress in a ceramic member, and more particularly to a method for measuring residual stress distribution in the depth direction in the vicinity of the surface.

[0002]

2. Description of the Related Art In recent years, ceramic members have been used for various component materials including electric / electronic component materials and structural component materials. Residual stress is measured as one means for evaluating the reliability of such a ceramic member.

That is, a ceramic member is often joined to a metal member and used as a composite member. However, if the difference in the coefficient of thermal expansion between the ceramic member and the metal member is large, residual stress occurs near the bonding interface between the ceramic members. This residual stress causes a crack in the ceramic member to cause the bonded body to break, or has a bad influence such that the bonding strength is reduced even if the bonded body is not broken. Therefore, it is important to evaluate the residual stress in the surface layer and the inside in order to control the quality of the ceramic-metal bonded body. In addition to the ceramic-metal bonded body, the quality control of the ceramic member of various shapes can be performed by evaluating the shape of the ceramic member and the residual stress caused by the manufacturing process such as the sintering process and the processing process. ..

Conventionally, numerical analysis methods such as the finite element method (FEM) and the boundary element method (BEM) have been mainly used as a method for evaluating the residual stress of a ceramic member. According to these methods, the stress distribution from the surface layer to the inside of the ceramic member can be estimated in detail. However, in actual ceramic members and ceramics-metal bonded bodies, it is often different from the analytical model, and it was necessary to actually measure the residual stress distribution.

As a method of actually measuring the residual stress of the ceramic member, there is known a sin ² ψ method or the like in which the lattice plane spacing of the crystal which changes in proportion to the magnitude of the residual stress is measured by X-ray diffraction. This method using X-ray diffraction can measure residual stress non-destructively and can measure residual stress in a minute portion in detail if the X-ray flux is miniaturized. Therefore, it can be used as a stress evaluation or quality control method in a local region. Attention has been paid.
This method has been recently developed as a micro X-ray method, and measurement examples of ceramics flat plate bonded bodies and the like have been reported (see Bulletin of the Japan Institute of Metals, 29 (1990) 924, etc.).

[0006]

The X-ray residual stress measuring method represented by the minute X-ray method described above has the advantage that the residual stress in the minute portion can be accurately measured. There is a problem that the measurement area is limited to the vicinity of the surface of the ceramic member up to the penetration depth of the line and the residual stress value can be measured only as an average value up to the penetration depth of the X-ray.

As a residual stress measuring method inside the ceramic member, a method using a neutron beam having a high penetrating ability has been developed, but not only the radiation source is limited, but also the obtained residual stress value is measured from the surface layer. It has a problem of lack of reliability such as an average value up to the inside or a value of only a certain plane orientation may be obtained, and it is considered that it will take some time for practical use. It has also been practiced to expose the inner surface by grinding or cutting and measure the residual stress on that surface by the X-ray method, etc. Was hard to get. Also, in the X-ray method, a triaxial stress analysis method based on the integration method has been proposed, but it has a drawback that the calculation is complicated.

By the way, according to the residual stress distribution estimated by the above-mentioned numerical analysis method, a large stress gradient is often generated in the vicinity of the surface layer of the ceramic member, and a large tensile stress gradient exists in the ceramic member weak against tensile stress. This has been a cause of reducing the life and reliability of the member. Since such a stress gradient appears largely in the vicinity of the ceramic / metal bonding interface, efforts have been made to reduce the maximum principal stress. At the same time, the emergence of a method for evaluating the stress gradient in the depth direction that occurs near the surface of the ceramic member was expected.

Further, in the ceramic-metal bonded body, the generated stress differs depending on the distance from the bonded interface and the position in the bonded interface direction, and the maximum principal stress of residual stress acts in the vicinity of the bonded body periphery near the bonded interface. Since it is known to do so, it is important to measure the residual stress of a minute portion corresponding to each stress generation position in order to confirm the reliability and reflect it in the design and manufacturing process. Therefore, there has been a strong demand for the development of a non-destructive method capable of accurately obtaining the residual stress in the depth direction in the minute portion of the ceramic member.

The present invention has been made to cope with such a problem, and it is possible to accurately and nondestructively measure the residual stress distribution in the depth direction in a minute portion near the surface layer of a ceramic member. An object of the present invention is to provide a method for measuring residual stress of a ceramic member as described above.

[0011]

That is, in the residual stress measuring method for a ceramic member according to the present invention, the penetration depth is different in a ceramic member having a flat or curved surface.
From the diffracted X-rays obtained by irradiating two or more X-rays individually
The residual stress is obtained by applying the sin ² ψ method, and the residual stress gradient in the depth direction near the surface is obtained from the obtained residual stress value and the penetration depth of the X-rays. It is characterized by evaluating the depth direction distribution of.

[0012]

[Function] The penetration depth of X-rays into the ceramic member is
It is determined by the wavelength and the ceramic material. Therefore, using two or more types of X-rays with different wavelengths, si
If the residual stress is obtained by applying the n ² ψ method, residual stress values with different measurement depths can be obtained. These residual stress values are obtained as average residual stress values up to the penetration depth of the X-ray used.
Therefore, if there is a stress distribution in the depth direction at the measurement location, there will be a difference in the obtained average residual stress values. Therefore, the residual stress gradient in the depth direction can be obtained from the difference between the average residual stress values and the penetration depth of X-rays.

[0013]

Embodiments of the present invention will now be described with reference to the drawings.

First, the residual stress measuring device used in this embodiment will be described. FIG. 1 is a configuration diagram showing an example of a measuring apparatus to which the residual stress measuring method of the present invention is applied.

In the figure, 1 is an X-ray tube which serves as an X-ray source for diffraction. X-rays 2 emitted from this X-ray tube 1.
Passes through the filter 3 and is extracted as a single wavelength X-ray 4. The single-wavelength X-rays 4 which have passed through the filter 3 are collimated into a predetermined spot having a small diameter by a collimator 5 having a double pinhole, and the small X-rays 6
Is irradiated on the ceramic member 8 as the object to be measured, which is arranged at the central position of the goniometer 7. An X-ray detector for measuring the intensity and diffraction angle of the diffracted X-rays 9 diffracted by the measurement surface 8a of the ceramic member 8 to be measured, such as a position-sensitive device, is provided on the outer peripheral portion of the above-mentioned goniometer 7. A proportional detector (PSPC) 10 is arranged. The filter 3 may be installed immediately before the position-sensitive proportional detector 10.

The target material of the X-ray tube 1 is appropriately selected according to the ceramic member to be measured so that the diffraction peak is an isolated peak on the high angle (2θ) side and the diffraction intensity is large. To do. Table 1 shows an example of target materials of interest and their K-series wavelength values.

[0017]

[Table 1]

The wavelength of the characteristic X-ray by the target shown in Table 1 is in the range of about 0.07 nm to 0.3 nm, and the penetration depth of the X-ray can be variously changed by these. In the present invention, two or more types of characteristic X-rays are selected from the characteristic X-rays arranged from the long wavelength side, that is, the shallow intrusion wave to the short wavelength side, that is, the deep intrusion wave, as shown in Table 1. Therefore, the penetration depth of X-rays into the ceramic member is made different.

The characteristic X-rays satisfying the above conditions suitable for residual stress measurement and the diffraction peaks of the measured ceramics are exemplified as follows. When the specimen is a β-Si ₃ N ₄ sintered body, the diffraction peak of the (411) plane by the V-Kα ₁ ray (2θ = 1
52.67deg), Cr-Kα ₁ ray diffraction peak of (212) plane
(2θ = 131.47deg), diffraction peak of (323) plane due to Cu-Kα ₁ ray (2θ = 141.45deg) is due to Cr-Kα ₁ ray in the case of α-Al ₂ O ₃ sintered body ( Diffraction peak of (1,0,10) plane (2
θ = 135.03deg), the diffraction peak (2θ = 136.11deg) of the (416) plane due to the Cu-Kα ₁ ray is due to the Cr-Kα ₁ ray in the case of the ZrO ₂ sintered body (Y-TZP). 133) diffraction peak (2θ
= 152.09deg), the diffraction peak (2θ = 140.22deg) of the (026) plane due to the Cu-Kα ₁ line is the case of the SiC sintered body (6H),
Diffraction peak of (116) plane by Cr-Kα ₁ line (2θ = 121.69d
eg), Cu-Kα ₁ ray diffraction peak of (306) plane (2θ = 1
34.09 deg) and the like are preferably used in the case of AlN sintered body, such as the diffraction peak (2θ = 148.26 deg) of the (205) plane by the Cu-Kα ₁ line.

As a combination of two or more kinds of characteristic X-rays suitable for measuring the distribution of residual stress in the depth direction, for example, Table 2
As shown in, V-Kα ₁ line, Cr-Kα ₁ line and Cu-K line
An example is a combination of α ₁ rays and the like. These have wavelengths of 0.250348 nm, 0.228964 nm and 0.154050 nm, respectively, and the penetration depth differs depending on the ceramic material. Here, the penetration depth t of the X-ray is calculated by the following equation.

[0021]

[Equation 1]

Table 2 shows the effective X-ray penetration depth calculated by the equation (2) for each ceramic material. Table 2 also shows each diffraction surface and the value of 2θ ₀ . For example, in the Si ₃ N ₄ sintered body, the penetration depth of the Cr-Kα ₁ ray is 10.2 μm, and Cu-
The penetration depth of the Kα ₁ line is 35.1 μm. The residual stress values obtained are measured as the average residual stress values up to these depths. The penetration depth depends on the incident angle ψ of the X-ray and changes as shown in FIG. 2 in the case of, for example, a Si ₃ N ₄ sintered body. Table 2 shows the maximum penetration depth when ψ = 0 degree.

[0023]

[Table 2]

The area of the irradiation area of the minute X-rays 6 is s
In the in ² ψ method, it is necessary to set the number of crystal grains in the X-ray irradiation region to be 1000 or more, and it is also necessary that the crystal grains in the X-ray irradiation region are polycrystals that are not oriented.
The irradiation area of the micro X-ray 6 satisfies the above conditions,
It is preferably set to 0.2 mm ² or less. It is more preferably 0.1 mm ² or less. In this way, the residual stress distribution can be measured in more detail by collimating the X-rays on the spot of a small diameter. In addition, accurate measurement is possible even when the surface to be measured is a curved surface.

Further, when the surface to be measured is a curved surface, the diameter of the irradiation area of the minute X-rays on the surface to be measured is d, the radius of curvature of the surface to be measured is r, and a value twice this radius of curvature r. Where D is D, so that the ratio d / D is 1/15 or less,
It is preferable to collimate single wavelength X-rays. By setting the irradiation area diameter d of the minute X-rays so that the above-mentioned d / D ratio satisfies 1/15 or less, the influence of the curvature of the measured surface can be almost eliminated, and accurate diffraction can be performed. An X-ray peak can be obtained, and the residual stress can be accurately measured even if the surface to be measured has a curved surface.

The ceramic member 8 to be measured is, for example, a flat, spherical or cylindrical ceramic member, or a flat plate-shaped ceramic member having a partially curved surface and having a flat surface to be measured. It is possible to apply various ceramic members up to a curved surface. Specifically, from single parts such as spherical ceramic parts such as bearing balls, cylindrical ceramic parts such as long links, to composite parts such as cylindrical ceramic-metal joint parts such as turbo rotor shafts, It can be applied to ceramic parts. Further, it is also applicable to a ceramic member when an external stress is applied.

The residual stress measuring device having the above structure measures the residual stress as follows. The residual stress generated in the ceramic member changes the lattice plane spacing (d value) of the crystal in proportion to the magnitude of this stress. When the generated residual stress is a tensile stress, the surface distance d in the direction parallel to the stress becomes small, and the surface distance d in the direction perpendicular to the stress becomes large. In the case of compressive stress, the opposite is true. Utilizing this property, the angle (X-ray incident angle) ψ formed by the object measurement surface normal N and the lattice surface normal N ′ is calculated as shown in FIGS. 3 (a), (b), and (c). The residual stress σ is obtained from the following equation by changing the X-ray irradiation while changing the diffraction angle (2θ) of a specific diffraction peak within the X-ray penetration depth.

[0028]

[Equation 2]

(Where σ is residual stress (kgf / mm ² ), E is Young's modulus (kgf / mm ² ), ν is Poisson's ratio, θ ₀ is standard Bragg angle.) K is material and measurement wavelength. Since the stress constant is determined by, the measured values (ψ and 2θ) are shown in Fig. 4.
As shown in FIG. 2, a residual stress σ can be uniquely obtained by creating a graph of 2θ and sin ² ψ, obtaining a gradient by, for example, the least squares method, and multiplying it by K.

In the present invention, two or more types of characteristic X-rays are individually used to measure the residual stress at the same point by the above-mentioned sin ² ψ method. Where the penetration depth is different 2
Since the characteristic X-rays of more than one kind are individually used, the residual stress value can be obtained as an average residual stress value up to the penetration depth of each X-ray. Therefore, if a stress gradient exists in the depth direction, the residual stress value obtained varies depending on the stress gradient. Therefore, the stress gradient in the depth direction can be quantitatively obtained from the difference between the residual stress values and the X-ray penetration depth.

Next, a specific measurement example using the residual stress measuring method of the present invention will be described.

Example 1 First, a cylindrical ceramic-metal bonded body was manufactured as an object to be measured by the following procedure. As shown in FIG.
10 mm diameter x 0.2 mm thick copper to be a stress buffer layer between a cylindrical ceramic member 11 made of ₃ N ₄ sintered body and having a diameter of 10 mm and a length of 10 mm, and a steel material (S45C) 12 having the same shape. A brazing filler metal 14 with a member 13 interposed and a Ag-Cu foil with a thickness of 60 μm and a Ti foil with a thickness of 3 μm between the surfaces to be joined
Inserted as. The laminate is then placed under vacuum at about 830
The ceramic member 11, the steel material 12 and the copper member 13 were heat-bonded by heat treatment under the condition of 6 ° C. for 6 minutes to produce a columnar ceramic-metal bonded body 15.

Cylindrical ceramics obtained in this way
Regarding the metal bonded body 15, of the residual stress of the ceramic member 11, the vertical stress σ _{z in} the axial direction (z direction in the drawing) and the vertical stress σ _θ in the circumferential direction (θ direction in the drawing) were measured. The measurement conditions were as follows.

As the specific X-ray, 50 kV, 160 mA of Cr-Kα
₁ line (wavelength 0.2289nm) and Cu-Kα ₁ line (wavelength 0.154050n)
m) and the irradiation diameter of X-ray was set to 0.15 mm at φ = 0 degree. The X-ray incident angle ψ was set to 5 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees and 35 degrees (parallel tilt method). When the X-ray incidence angle ψ is 35 degrees, the X-ray irradiation area diameter d (ellipse major axis) is 0.32.
It was mm. Therefore, the d / D ratio is 1/31. Also, ψ
The number of Si ₃ N ₄ crystal grains on the surface within the irradiation area at = 0 degree is about 2000, and the penetration depth of (1-1 / e) (10.2 μm when irradiated with Cr-Kα ₁ ray) The total number of crystal grains up to
The number was 7,000, which was sufficient to measure the residual stress by applying the sin ² ψ method.

The measurement is 2θ = 131.47 deg for Cr-Kα ₁ line
Of the (212) plane diffraction peak and 2θ = for the Cu-Kα ₁ line
Using the diffraction peak of the (323) plane at 141.45 deg, a graph of 2θ-sin ² ψ was created from the deviation of the diffraction peak.
Then, the gradient of these graphs and the stress constant (Cr-Kα
₁ line: K = -883MPa / deg, Cu-Kα ₁ line: K = -688MPa / de
g) and were used to calculate the residual stress, respectively. The measurement positions were set at several positions in the axial direction from the vicinity of the bonding interface at predetermined intervals.

As a measurement result, FIG. 6 shows the axial distribution of the vertical stress σ _{z in the} axial direction and the vertical stress σ _{θ in} the circumferential direction of the residual stress. The axial vertical stress σ _z is a large tensile stress, and the circumferential vertical stress σ _θ is a compressive stress.
_z decreases monotonically with increasing distance from the bond interface, and σ
Along with _θ , it tends to become zero at the sample end. But,
Σ _z measured by both X-rays of Cr-Kα ₁ and Cu-Kα ₁
There is a subtle difference in the value of, and the value by the Cr-Kα ₁ line is larger than the value by the Cu-Kα ₁ line. The difference was larger as it was closer to the joint interface, and there was a difference of 2.2 kg / mm ² at a location 0.1 mm away from the joint interface. This is because there is a large stress gradient in the depth direction near the joint interface.
It is considered that the averaging effect worked for Cu-Kα rays with a large penetration depth. The penetration depth of both X-rays is Cr-Kα according to Table 2 where the intensity of the incident X-ray becomes (1-1 / e).
10.2μm ₁ line, which is 35.1μm in Cu-K [alpha ₁ line. Therefore, the stress gradient in the depth direction obtained by this example is
Approximately 0.088 kg / mm ² per μm at the point of attenuation to (1-1 / e)
Became. The stress gradient in the depth direction near the central part of damping (1-1 / 2e) was about 0.127 kg / mm ² per 1 μm.

As described above, by using two or more kinds of X-rays having different penetration depths and measuring the residual stress individually,
The residual stress gradient in the depth direction in the vicinity of the surface can be obtained.

Example 2 As shown in FIG. 7, between two steel materials (S45C) 21 having a cross-sectional diameter of 6 mm in the vicinity of the joint, a cylindrical column of 6 mm in diameter and 5 mm in width made of a Si ₃ N ₄ sintered body was used. Of the ceramic member 22 of which the diameter is a stress buffer layer between these joint surfaces.
A copper member 23 having a size of 6 mm and a thickness of 0.2 mm was interposed.
Then, a brazing filler metal (not shown) similar to that of Example 1 is inserted between the surfaces to be joined, and heat-bonded under the same conditions as in Example 1 to form a columnar ceramic-metal bonded body 24.
(Tensile test piece) was produced.

Cylindrical ceramics obtained in this way
For metal bonded body 24, of the residual stress of the ceramic member 22, the axial normal stress sigma _z of (z-direction), the vertical stress sigma _theta, and theta-z in plane [pi / 4 in the circumferential direction (theta direction)
Direction of the normal stress σ _T, Cr -Kα ₁ line and Cu-K [alpha ₁
Each was measured using a line. The measurement conditions were the same as in Example 1.

FIG. 8 shows the axial distribution of the normal stresses σ _z , σ _θ and σ _T. The bonded sample used in this example is the same as in Example 1.
Since the two bonded bodies are combined, the stress distribution is bilaterally symmetrical with respect to the center line of the ceramic member 22. That is, σ _z and σ _T show the maximum tensile stress in the vicinity of the bonding interface, σ _θ shows the maximum compressive stress, and both show the minimum at the central portion.

As is clear from FIG. 8, a clear difference was observed in the stress value by X-ray also in this example. C
The residual stress measurement values for the r-Kα ₁ line show larger tensile stress values and compressive stress values than those for the Cu-Kα ₁ line, and the difference tends to increase as the stress value increases. This difference can be interpreted as the averaging effect due to the difference in the penetration depth of X-rays at the site where the stress gradient in the depth direction exists.

The maximum difference in normal stress σ _z at a location 0.1 mm from the joint interface due to X-ray was 4.2 kg / mm ² . From this, when the stress gradient in the depth direction is obtained in the same manner as in Example 1, it is about 0.169 kg / mm ² per 1 μm, (1-1 / 2e) attenuation in comparison with the X-ray (1-1 / e) attenuation point. About 1 μm per point
It was 0.243 kg / mm ² .

Example 3 The distribution of residual stress in the depth direction was measured by using two types of plate-shaped joining test pieces 31 of 3 mm × 4 mm × 40 mm as shown in FIG. The bonded body 31 is 5 mm thick with the ceramic member 32.
Steel plate (S45C) 33 of No. 3 is joined by a 0.3 mm thick copper plate 34 by the active metal method using a Ti—Cu—Ag type brazing material as in Example 1. And the ceramic member 3
As the No. 2, two kinds of bonded bodies 31 were prepared by using the Si ₃ N ₄ sintered body and the Al ₂ O ₃ sintered body, respectively.

Near the joint end of the joint test piece 31 (A in the figure)
Residual stress on the Cr-Kα ₁ line and Cu-Kα
Each was measured using _one line. Point A is a site separated by 0.1 mm from each side of the test piece and the bonding interface. As shown in Table 2, the diffraction plane used for the measurement of the test piece made of the Al ₂ O ₃ sintered body is the diffraction peak (2θ = 135.03) of the (1,0,10) plane in the Cr-Kα line _1. deg), for Cu-Kα ray ₁ (41
This is the diffraction peak of the 6) plane (2θ = 136.11 deg). In the case of an Al ₂ O ₃ sintered body, the Cr-Kα ₁ line and the Cu-Kα ₁ line are (1-
1 / e) There is a difference of 26.1 μm in penetration depth.

The residual stress at the point A of the test piece made of the Si ₃ N ₄ sintered body was 3.5 kg / mm for the Cr-Kα ₁ line and the Cu-Kα ₁ line.
There was a difference of ² . Therefore, the stress gradient in the depth direction obtained by (1-1 / e) penetration depth is about 0.141 kg / mm ² per 1 μm.
Became. In addition, the residual stress at the point A of the test piece made of the Al ₂ O ₃ sintered body was measured by the difference of ² kg / mm ² , and the distribution in the depth direction was
(1-1 / e) About 0.077 kg / mm ² per 1 μm depth, (1-1 / 2e)
The depth was calculated to be about 0.111 kg / mm ² per 1 μm.

[0046]

As described above, according to the residual stress measuring method for a ceramic member of the present invention, it is possible to quantitatively determine the residual stress gradient in the depth direction in the vicinity of the surface. Therefore, it becomes possible to measure the residual stress in more detail due to various factors such as the manufacturing process of the ceramic member, and it is possible to perform reliable quality evaluation.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of an example of a measuring apparatus used in a residual stress measuring method of the present invention.

FIG. 2 is a diagram showing a difference in penetration depth of X-rays into a Si ₃ N ₄ sintered body as ψ-angle existence.

FIG. 3 is a diagram showing a principle of measuring residual stress by X-ray.

FIG. 4 is a diagram for explaining a method of calculating a residual stress by X-ray.

FIG. 5 is a perspective view showing a cylindrical ceramics-metal bonded body used for measuring the distribution of residual stress in the depth direction in one example of the present invention.

6 is a cross-sectional view of the cylindrical ceramic-metal bonded body shown in FIG.
It is a graph which shows the residual stress distribution measured individually using two types of characteristic X-rays.

FIG. 7 is a perspective view showing a cylindrical ceramic-metal bonded body used for measuring the distribution of residual stress in the depth direction in another example of the present invention.

FIG. 8 is a view showing the cylindrical ceramic-metal bonded body shown in FIG.
It is a graph which shows the residual stress distribution measured individually using two types of characteristic X-rays.

FIG. 9 is a perspective view showing a flat plate-ceramic-metal bonded body used for measuring the distribution of residual stress in the depth direction in still another embodiment of the present invention.

[Explanation of symbols]

1 ... X-ray tube 2 ... X-ray emitted from X-ray tube 3 ... Filter 4 ... Single wavelength X-ray 5 ... Collimator 6 ... Micro X-ray 7 ... Goniometer 8 …… Ceramics member 9 …… Diffraction X-ray 10 …… Position-sensitive proportional detector Applicant Toshiba Corporation Representative Attorney
Saichi Suyama (1 other person)

Claims (2)

[Claims] 1. A ceramic member having a flat or curved surface is individually irradiated with two or more types of X-rays having different penetration depths, and the sin ² ψ method is applied to each of the obtained diffracted X-rays. Obtaining the residual stress, obtaining a residual stress gradient in the depth direction near the surface from the obtained residual stress value and the penetration depth of the X-ray, and evaluating the distribution of the residual stress in the ceramic member in the depth direction. A method for measuring residual stress in a ceramic member, comprising: 2. The method for measuring residual stress of a ceramic member according to claim 1, wherein the two or more kinds of X-rays are Sc, Ti, V 2, Cr, Fe, Co, Ni,
A residual stress measuring method for a ceramic member, comprising using two or more kinds of targets selected from Cu and Mo individually.