JP2001296258A - Crystal orientation measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal orientation measuring method, capable of detecting a wrong crystal orientation generated systematically with a specific crystal orientation relation between a correct crystal orientation and a wrong crystal orientation measured by the crystal orientation measuring method for mapping the crystal orientation, by using an electron beam backward scattering diffraction image or a Kossel diffraction image, and correcting the wrong crystal orientation. SOLUTION: This method is characterized, by detecting the wrong crystal orientation generated systematically with the specific orientation relation between the measured correct crystal orientation and the wrong crystal orientation by being distributed on a fixed curve connecting each of poles (100), (010) and (001) or on its periphery on a stereo projection drawing plane of the wrong crystal orientation, and correcting the wrong crystal orientation by utilizing the distribution. In the crystal orientation measuring method, the wrong crystal orientation is detected by the fact that Eulerian angles, giving the wrong crystal orientation exists concentrically in a subspace region of a Eulerian angle space, and corrected by utilizing the wrong Eulerian angles.

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 a crystal orientation of a crystal grain and displaying the data two-dimensionally or three-dimensionally. The present invention relates to a crystal orientation measuring method capable of detecting and correcting a systematically occurring error occurring in a specific orientation relationship with an incorrect crystal orientation to obtain a correct crystal orientation.

[0002]

2. Description of the Related Art Electron channeling pattern (hereinafter abbreviated as ECP) analysis methods using scanning electron microscopes and X-ray Kossel image analysis methods using a scanning electron microscope have replaced conventional micro Laue methods and the like as methods for measuring the crystal orientation of a minute region. To be used. In this method, a microscopic region is irradiated with an electron beam, a scattered diffraction pattern from the electron beam is photographed on an imaging tube, and the characteristics of the pattern are automatically analyzed to identify the crystal orientation. Furthermore, the distribution of the crystal orientation on the sample surface is measured by moving the electron beam irradiation minute area and repeating the pattern analysis, and the map is displayed two-dimensionally or three-dimensionally.

[0003] The map obtained in this way displays the orientation of each crystal grain in a visually easy-to-understand manner, and is an effective method for analyzing, for example, a recrystallization texture. It is also effective as a method of quality control of a material as a method of monitoring the recrystallization texture.

[0004]

However, the measurement of the crystal orientation may be erroneously performed. Such errors often occur when the previous diffraction pattern is unclear depending on the state of the sample surface. However, there are two types of errors that occur at random and those that occur with a certain regularity.

[0005] The former case inevitably occurs with a certain probability. In this case, since it occurs in isolation, it can be removed by an existing processing method, and does not cause a serious problem. The latter is likely to occur when the diffraction pattern to be analyzed is mainly composed of a highly symmetric pattern. Therefore, since it occurs only in a specific crystal grain region, it is characteristically concentrated in a specific region. Such an error has no effect when the existing processing method is applied, and eventually gives an incorrect orientation distribution. In such a case,
Usually, the surface of the sample is polished by etching or the like to make it smooth to avoid it.

However, if such a treatment is applied to the sample, the surface state has been artificially changed. Such changes can be fatal in some cases. For example, when observing a secondary recrystallization process by heat treatment, correct information cannot be obtained. In addition, when the material is used on a production line for quality control, there is a problem in that it takes a long time to adjust a sample, which causes a decrease in production efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has been made in view of the above circumstances. The present invention provides a method of obtaining a correct crystal orientation distribution by recognizing and correcting it to a correct index. The present invention is achieved by the following method.

(1) A crystal orientation measurement method for measuring the crystal orientation of crystal grains on a sample surface using an electron beam backscatter diffraction image or a Kossel diffraction image and mapping the crystal orientation, wherein the crystal orientation measurement method is used. The systematically generated erroneous crystal orientation that occurs with a specific orientation relationship between the correct crystal orientation and the erroneous crystal orientation measured in (1) is (100), (010) in the stereo projection plane of the erroneous crystal orientation. , (0
01) The method of measuring a crystal orientation, wherein the detection is performed by being distributed on or near a fixed curve connecting the poles, and the incorrect crystal orientation is corrected using the distribution.

(2) A method for measuring the crystal orientation of crystal grains on the surface of a sample using an electron beam backscatter diffraction image or a Kossel diffraction image and mapping the crystal orientation, wherein the crystal orientation measurement method is used. The systematic erroneous crystal orientation that occurs with a specific crystal orientation relationship between the correct crystal orientation and the erroneous crystal orientation measured in, is the Euler angle that gives the erroneous crystal orientation is a subspace region of the Euler angle space. Detecting the presence of the erroneous crystal orientation and correcting the erroneous crystal orientation using an Euler angle giving the erroneous crystal orientation.

(3) A method for measuring the crystal orientation of crystal grains on the surface of a sample using an electron beam backscatter diffraction image or a Kossel diffraction image and mapping the crystal orientation, wherein the crystal orientation measurement method is used. The region where the systematic error has occurred with a specific crystal orientation relationship between the correct crystal orientation and the incorrect crystal orientation measured in the above, the fine crystal in the crystal orientation map drawn by the crystal orientation measurement method The crystal orientation measuring method according to the above (1) or (2), wherein the crystal orientation is detected by a grain pattern.

(4) A method for measuring the crystal orientation of crystal grains on the surface of a sample using an electron beam backscatter diffraction image or a Kossel diffraction image and mapping the crystal orientation, wherein the crystal orientation measurement method is used. The region in which the systematic error has occurred having a specific crystal orientation relationship between the correct crystal orientation and the incorrect crystal orientation measured in the above is defined by the misorientation angle of the measured crystal orientation with respect to the predetermined crystal orientation. (1) or wherein the distribution of the misorientation angle on the sample surface is processed by high-speed wavelet transform and detected by indicating a high frequency in a region limited by the high-speed wavelet transform. The crystal orientation measuring method according to (2).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The crystal orientation of crystal grains on the surface of a sample is measured using an electron beam backscatter diffraction image or a Kossel diffraction image.
In the method of measuring the crystal orientation distribution, a different crystal orientation may be obtained even with a measured value at a point belonging to the same crystal grain. This is observed when the crystal orientations differ by about several degrees due to the existence of sub-grain boundaries. However, it is sometimes observed that an error occurs in the crystal orientation measurement. Such errors in crystal orientation measurement include those that occur randomly and those that occur systematically.

The former is characterized in that it occurs in isolation, and the latter is characterized in that it occurs densely in a certain area. An error that occurs randomly is basically an accidental occurrence, and therefore occurs in isolation in the crystal orientation distribution map irrespective of the crystal orientation at the closest point. The systematically occurring errors are arbitrarily selected from a plurality of erroneous crystal orientations having a specific relationship to a correct crystal orientation, and are generated in a specific crystal grain region, and are dense and fine in a specific region. Recognized as a grain distribution.

The present invention relates to the detection and correction of systematically occurring errors. The error systematically described here is, as described above, an error that is arbitrarily selected from a plurality of crystal orientations having a specific relationship with a correct crystal orientation, and is caused by: Crystal diffraction pattern (electron backscatter diffraction pattern,
Or Kossel diffraction pattern). Diffraction patterns are composed of figures with high symmetry, and the center of symmetry is identifiable, but if it is not clear at the peripheral part away from the center of symmetry, the correct figure is considered as a figure rotated about the center of symmetry. I will recognize. Here, the rotation angle is determined by the symmetry of the diffraction pattern. That is, assuming that the symmetry of the rotation center point is N times symmetric, the rotation angle is 180 × K / N degrees. Where K = 1,
2,. . N.

Therefore, N erroneous recognitions can occur in such a figure. Also, this rotation angle is generally
It is larger than the rotation angle that forms the sub-grain boundaries. Which of these will occur is uncertain because it is affected by the condition of the sample and the like. It is considered that false recognition occurs with almost the same probability. Therefore, when measuring a number of points on the surface of a crystal grain giving such a diffraction pattern, a different crystal orientation is obtained each time the measurement point is changed,
Eventually, an erroneous crystal orientation distribution in which one crystal grain is composed of many fine crystal grains will be obtained.

However, these erroneous crystal orientation distributions have a specific relation to the correct crystal orientation, as described above. Therefore, it occupies a specific region in the space defined by the crystal orientation. Here, the space defined by the crystal orientation is generally a space represented by coordinates on a stereo projection diagram, or a space defined by Euler angles indicating the crystal orientation. That is, these crystal orientations are displayed in the vicinity of a specific figure on the stereo projection. In the case of the Euler angle space, it is displayed near a specific Euler angle. Therefore, it is possible to correct the pattern by using these.

For example, on a stereo projection diagram, the image is displayed near a specific circle or a plurality of points on an arc. Here, one of the plurality of points where the points are concentrated is a point representing the correct crystal orientation. In many cases, the point giving the correct crystal orientation occurs most frequently. Therefore, the crystal orientation at the most frequent point may be corrected for the crystal orientation at another concentrated point. However, depending on the condition of the sample,
It is possible that the most frequent concentration points do not give the correct crystallographic orientation.

For this reason, it is preferable to determine the concentration point giving the correct crystal orientation so that there is no inconsistency by comprehensively considering the history and state of the sample. The same is true for the case of Euler angle space. In the case where the erroneous measurement direction is corrected to the correct measurement direction, if only one crystal direction is given as the correct crystal direction, the corrected state is recognized as a single crystal region having a single crystal direction. In many cases, one crystal grain is considered to be a single crystal, and there is no problem.

However, a single crystal orientation is usually observed as a crystal orientation having a certain size, reflecting the state of the measuring apparatus and the state of the sample. Therefore, it is preferable to perform correction so as to reproduce a state close to the distribution state around the concentration point corresponding to the observed correct crystal orientation. Since the distribution around the concentration point can be approximated by the normal distribution in many cases, the distribution around the correct azimuth is approximated by the normal distribution, and the corrected azimuth is given by the probability density defined by the normal distribution. It can be corrected to the correct crystal orientation with a certain distribution.

The area where the erroneous measurement has occurred is as follows.
As described above, the crystal orientation distribution often appears to be composed of fine crystal grains in a specific region. That is,
In a specific region, it is observed that the crystal orientation fluctuates finely spatially. Therefore, it can be said that the distribution has a high spatial frequency in that region. Generally, when analyzing the fineness of the fluctuation of the distribution of a certain physical quantity, the distribution is subjected to a Fourier transform, and the distribution is analyzed at a spatial frequency. In other words, the higher the fine fluctuation, the higher the spatial frequency component, and the lower the fluctuation, the lower the high spatial frequency component.

The region where the systematic erroneous measurement has occurred is observed as if the crystal orientation fluctuates spatially finely. 6 shows a distribution concentrated on frequency components.
However, the general Fourier transform is to transform the original coordinate area into the spatial frequency area, and cannot analyze the spatial frequency distribution in a specific coordinate area.

In such a case, the spatial frequency distribution state can be shown on the sample coordinates by applying a wavelet transform instead of the Fourier transform. That is, it is possible to easily find a specific region showing a high spatial frequency distribution. Here, it is preferable that the wavelet transform is a fast wavelet transform to which the fast Fourier transform is applied from the viewpoint of processing speed. The correct crystal orientation distribution can be obtained by correcting the erroneous measurement by applying the above-described method to the region thus found.

[0023]

The present invention will be described in more detail with reference to specific measurement results. Example 1 FIG. 1 shows an example in which data measured using a measuring device that reads a channeling pattern generated by backscattering of an electron beam and identifies a crystal orientation without any processing is output. The sample used was an iron plate. Since only rough polishing is applied, the surface has large irregularities and measurement errors are likely to occur. In addition, a black region 3 in the figure is a region that cannot be measured due to irregularities.

A fine granular pattern can be seen over most of FIG. Such a granular area can be divided into an area 1 and an area 2 as shown in FIG. here,
Region 1 shows a <110> crystal orientation in the sample normal direction,
It is known that a <001> crystal orientation is shown in the sample rolling direction. Hereinafter, this crystal orientation is referred to as {110} <001>.

FIG. 2 shows a typical diffraction pattern obtained in the region 1. The diffraction pattern appearing here naturally reflects the crystal orientation of the sample region that emits the diffraction line, but further reflects the position of the fluorescent screen that captures it. In the present embodiment, the positional relationship is such that the angle between the normal direction of the fluorescent screen and the normal direction of the sample is 20 degrees. The diffraction pattern in FIG. 2 is a pattern in which there is one point having six-fold symmetry in the upper right part of the screen as shown in the figure, and a band is radially projected with that point as the center of symmetry 4. The portion far from the center of symmetry 4 is somewhat unclear.

When trying to recognize such a diffraction pattern, the correct one must be 30 degrees around the center point or 6 degrees.
In some cases, it is recognized as a diffraction pattern rotated by 0 degrees or 90 degrees. In other words, if the peripheral part located at a portion away from the center is unknown, there is only one six-fold symmetrical figure, and there are many equivalent solutions. However, those incorrect solutions have a specific relationship with the correct solution.

FIGS. 3 to 6 schematically show how the diffraction pattern shown in FIG. 2 is recognized. Here, the pattern shown in FIG. 5 is a correct pattern. Also, as will be described later with reference to FIG. 8, when the occurrence frequency of the pattern recognized in the area 1 in FIG. 1 is examined, it is found that the correct pattern, that is, the pattern corresponding to FIG. 5 has the highest frequency.

It can be seen that the fine distribution seen in region 1 of FIG. 1 is based on incorrect pattern recognition as shown above. That is, in FIG. 5, which is a correct pattern in the incorrect pattern recognition, <111> in FIG.
The pattern is recognized as a pattern rotating in a plane around a point E representing the azimuth. This happens when the channeling pattern is unclear in this area,
It is considered that the cause is that, for example, a step is induced by heat treatment or the like in the crystal grains having a specific orientation, so that irregularities are generated on the surface.

Next, FIG. 7 shows a stereographic projection of the {100} crystal orientation corresponding to FIGS. In FIG.
Points indicated by A to D are points corresponding to the (100) pole of the crystal orientation shown in the patterns of FIGS.
These points A, B, C and D are arranged on a specific circle in the stereographic coordinates. Here, the center coordinates are

[0030]

(Equation 1)

Where the radius is

[0032]

(Equation 2)

Is on a circle that is Here, a =
tan (22.5 °). The center of this circle and A, B,
FIG. 8 shows the appearance frequency of each point using the angle formed by the line connecting the points C and D with the rolling direction as the center angle of each point. FIG. 8 shows that the appearance frequency of the correct pattern is the highest. You can see that it is. These azimuths are represented in this way because each of these azimuth relationships is in a specific azimuth relationship, and such azimuth relationships arise for the reasons set forth above.

From the above, the coordinates of the measured crystal orientation in the corresponding area on the stereo projection diagram are obtained, and when the coordinates become A, B, and D shown in FIG. 1, the measured crystal orientation is forcibly plotted. Correcting the point C shown in FIG. 1 makes it possible to obtain a correct crystal orientation. FIG. 9 shows a flowchart of this procedure. Before performing the operation shown in FIG. 9, it is desirable to know the correct orientation. In region 1 of FIG. 1, this method can be applied since the correct orientation is known.

However, in the region 2 which also shows a fine distribution, the correct orientation is not known in advance. In the area 2 of FIG. 2, the stereo projection coordinates of the azimuth of each point are calculated by the same procedure, a circle determined by a specific azimuth relationship is obtained, and the point having the highest frequency near the circle corresponds to the correct azimuth. . That is, the flow chart is as shown in FIG. Focusing on the fact that the frequency of appearance of the pattern corresponding to the correct azimuth is often the highest, correction can be made as follows. That is, a point on the stereo projection diagram where observation points are concentrated is obtained. next,
Assuming that the point with the highest concentration frequency among those concentration points represents the correct orientation, the observation points near the other concentration points are corrected to the points with the highest concentration frequency. That is, the flowchart shown in FIG. In the present embodiment, such a correction is made for the region 2 in FIG. In the present embodiment, since the concentration frequency of correct points is the highest, the result of such correction matches the result of correction in accordance with the flowchart of FIG.

The correct pattern in the area 2 in FIG. 2, that is, the most frequent pattern is the pattern shown in FIG. 4, and FIGS. 3, 5, and 6 are erroneous patterns. The circle for determination is shown in area 1 in FIG.
The circle was the same as the one used for the correction. FIG. 11 shows the crystal orientation distribution corrected in this manner. The fine distribution seen in the region 1 and the region 2 disappears, and it is clearly shown that noise based on erroneous measurement of a specific pattern has been removed. Here, the isolated noise remains,
This is based on a randomly generated error and can be corrected by conventional methods, which is more desirable.

The feature of the present method is, as described herein, to correct a systematic error having a specific orientation relationship with a correct crystal orientation, and it is preferable not to apply the method to a randomly generated erroneous measurement. . In addition, a sufficient method for correcting a random measurement error has been provided. Example 2 The orientation distribution of crystal grains on the sample surface was determined by electron beam backscattering for a sample containing crystal grains having a crystal orientation of {110} <001> in the iron crystal grains. FIG. 12 shows a crystal orientation map output from raw data as measured. It can be seen that there is a region 5 composed of fine crystal grains on the left side of FIG. This is due to the systematic erroneous measurement shown in the first embodiment. Also, this area 5 is {110} <001
It is known that the region has a crystal orientation of>. In the second embodiment, the crystal orientation is represented by Euler angles. FIGS. 13 to 15 show distributions of the measured Euler angles in this region.

Of the distributions shown in FIGS.
The correct orientation of Euler angles φ ₁ , φ, φ ₂ is indicated by an arrow at a position indicating the direction closest to the 0 ° <001> direction.
It can be seen that there are several distributions having strong spike-like peaks, reflecting the systematic error generated for the reason described in the first embodiment. The small peak corresponds to a randomly occurring measurement error. Therefore, a point having an Euler angle belonging to a relatively large peak in the drawing may be determined to be an erroneous measurement.

This is equivalent to the operation performed in the stereo projection space in the first embodiment in the Euler space, and is equivalent. Next, the distribution of the correct measured Euler angles is shown in FIGS. As shown in these figures, it can be seen that the correct data is also distributed with a certain width. Such a width reflects the measurement accuracy and the crystal state of the sample. Therefore, it is desirable to reflect such a width when correcting erroneous measurement data.

Therefore, in this embodiment, when the data is corrected to correct data, each Euler angle is generated with a probability density according to the normal distribution shown in FIGS. 16 to 18 to give a correct Euler angle. The center value of the correct Euler angle distribution shown in FIGS. 16 to 18 is true {110} <001>.
It should be the Euler angle giving the azimuth, but not here. This is based on the inclination of the sample setting direction and the like. To correct this, the orientation matrix G obtained from the center value of each correct Euler angle
Is a true {110} <001> azimuth azimuth matrix S, and the azimuth matrix obtained at all points is corrected from the right. Here, G, S, and D are as follows.

[0041]

(Equation 3)

[0042]

(Equation 4)

[0043]

(Equation 5)

Here, φ ₁ , φ, and φ ₂ are the center values in the normal distribution indicating the correct Euler angle distribution. FIG. 19 shows a map of the crystal orientation distribution obtained by such correction. Here, as seen in FIG.
The noise based on the systematic erroneous measurement in the 0 ° <001> azimuth region has been removed, and only the noise based on the erroneous measurement that occurs randomly is seen. These random noises can be removed by conventional correction methods.
FIG. 20 shows a crystal orientation distribution map obtained as a result.
This indicates that a correct crystal orientation distribution can be obtained. Comparative Example 1 FIG. 21 shows a crystal orientation distribution map obtained by only removing noise according to the conventional method without correcting the systematic erroneous measurement by the method in the example shown in Example 2. In the {110} <001> region on the left side of the drawing, it is clearly shown that many crystal grains have been generated.

This is because the conventional noise elimination method targets a measurement error that results in an isolated random orientation, that is, a measurement error that occurs randomly.
This is because erroneous measurements such as those in the 10 ° <001> region, each having a specific azimuth relationship, that is, measurement errors generated with correlation do not work effectively. Example 3 When a systematic erroneous measurement targeted by the present invention occurs, as seen in the previous examples, one or more crystal grains are observed as fine crystal grains throughout. However, it is desirable to find such an area automatically.

For this purpose, a wavelet transform can be used. That is, an appropriate amount characterizing the crystal orientation (hereinafter, this amount is referred to as Y) is obtained at each measurement point, a region where a locally high wave number component appears is detected, and stereo projection in that region is performed. Assuming that Y is distributed in the measurement area, Y is subjected to wavelet transformation with respect to the coordinates of the measurement sample.

Since the feature of the wavelet transform is to find the spatial frequency spectrum distribution in the spatial coordinate area, a high spatial frequency component is detected in the area where the fine crystal grains are generated. Therefore, a problematic region can be found by finding a region where high spatial frequency components are continuously generated. There is no restriction on the amount Y characterizing the crystal orientation, but it is preferably a scalar amount from the viewpoint of calculation time.

In this embodiment, the data used in the second embodiment is used, and Y is {110} <
001> The rotation angle with respect to the azimuth was adopted. The sample coordinates are nd depending on the number of steps n and the step length d for scanning the electron beam at the time of measurement. However, it is convenient to take the number of steps n as the sample coordinates. Adopted as. Assuming that the maximum value of the number of steps n is N, the spatial frequency f obtained by the sampling theorem is

[0049]

(Equation 6)

This is simple because the step length d determined by each measurement can be eliminated. In this embodiment,
Since two-dimensional coordinates are handled, the number of steps n, its maximum value N, and the spatial frequency f are two-dimensional quantities, and are _nx ,
_{n y, N x, N y} , f x, and f _y. Equation 6 holds between the components. The region where the value obtained by integrating the wavelet spectrum at each point in the region where the spatial frequency f is equal to or greater than １ ／ k (k is a natural number) is non-zero is h (h is the average crystal grain size equivalent step number s). An erroneous measurement area is set as a natural number.

In this embodiment, this is extended two-dimensionally.

[0052]

(Equation 7)

The region where the sum of the spectral components in the spatial frequency region is non-zero is

[0054]

(Equation 8)

If the area is continuous, the area is recognized as a target area. In this embodiment, since the average crystal grain size was 20 μm and the scan length was 4 μm, s _x = s _y = 5, and k = 5 and h = 2. High-speed wavelet transform was performed on the data, and the obtained wavelet spectrum was integrated in the spatial frequency domain represented by Equation 7, the distribution at each point was obtained, and the target area was specified by applying the above criteria.

As a result, a region almost overlapping with the fine granular region shown on the left side in FIG. 11 could be extracted. Further, the same crystal orientation distribution map as that shown in FIG. 18 was obtained by applying the erroneous measurement correction according to the present invention to that region.

[0057]

As is apparent from the above description, according to the present invention, it is possible to eliminate a correlated measurement error generated in the crystal grain orientation measurement and obtain a correct crystal orientation distribution.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of measuring the crystal orientation of an iron plate.

FIG. 2 is a photograph of an electron beam backscatter diffraction diagram.

FIG. 3 is an example of an electron beam backscatter diffraction pattern.

FIG. 4 is an example of an electron beam backscatter diffraction diagram.

FIG. 5 is an example of an electron beam backscatter diffraction pattern.

FIG. 6 is an example of an electron beam backscatter diffraction pattern.

FIG. 7 is a stereo projection view.

FIG. 8 is a diagram illustrating an example of the appearance frequency of crystal orientation recognition.

FIG. 9 is a flowchart illustrating an example of a crystal orientation correction method.

FIG. 10 is a flowchart illustrating an example of a crystal orientation correction method.

FIG. 11 is a crystal orientation distribution diagram showing an example after crystal orientation correction.

FIG. 12 is a diagram showing an example of measuring the crystal orientation of an iron plate.

13 is a diagram showing an example of the distribution of the Euler angles phi _1.

FIG. 14 is a diagram showing an example of a distribution of Euler angles Φ.

15 is a diagram showing an example of the distribution of Euler angles phi _2.

FIG. 16 is a diagram showing an example of a distribution of Euler angles φ ₁ .

FIG. 17 is a diagram illustrating an example of a distribution of Euler angles Φ.

FIG. 18 is a diagram showing an example of a distribution of Euler angles φ ₂ .

FIG. 19 is a diagram showing an example of crystal orientation distribution after crystal orientation correction.

FIG. 20 is a diagram showing an example of crystal orientation distribution after crystal orientation correction.

FIG. 21 is a diagram illustrating an example of a crystal orientation distribution after crystal orientation correction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Region 1 2 ... Region 2 3 ... Black region 4 ... Center of symmetry 5 ... Region composed of fine crystal grains A ... Point corresponding to pole of crystal orientation (100) B ... Polarity of (100) crystal orientation C: Point corresponding to the (100) pole of the crystal orientation D: Point corresponding to the (100) pole of the crystal orientation Y: Rolling direction

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshiyuki Ushigami 20-1 Shintomi, Futtsu-shi, Chiba F-term in the Technology Development Division of Nippon Steel Corporation (reference) 2G001 AA03 BA15 CA03 GA01 GA13 HA01 JA11 KA08 LA02 MA05

Claims (4)

[Claims] 1. A crystal orientation measurement method for measuring a crystal orientation of crystal grains on a sample surface using an electron beam backscatter diffraction image or a Kossel diffraction image, and mapping the crystal orientation. A systematically occurring erroneous crystal orientation that occurs with a particular crystal orientation relationship between the measured correct and erroneous crystal orientations is the (100), (010) in the stereo projection plane of the erroneous crystal orientation. , (0
01) A method for measuring a crystal orientation, wherein the detection is performed by distributing on or near a fixed curve connecting the poles, and the incorrect crystal orientation is corrected using the distribution. 2. A method for measuring a crystal orientation of crystal grains on a sample surface using an electron beam backscattering diffraction image or a Kossel diffraction image, and mapping the crystal orientation. The systematic erroneous crystal orientation that occurs with a specific crystal orientation relationship between the measured correct crystal orientation and the erroneous crystal orientation is the Euler angle that gives the erroneous crystal orientation is within the subspace region of the Euler angle space. Detecting the presence of the erroneous crystal orientation and correcting the erroneous crystal orientation using an Euler angle giving the erroneous crystal orientation. 3. A method for measuring a crystal orientation of crystal grains on a sample surface using an electron beam backscattering diffraction image or a Kossel diffraction image, and mapping the crystal orientation. The region where the systematic error occurs having a specific crystal orientation relationship between the measured correct crystal orientation and the incorrect crystal orientation is defined by fine crystal grains in the crystal orientation map drawn by the crystal orientation measurement method. 2. The method according to claim 1, wherein the detection is performed by a pattern.
Or the crystal orientation measuring method according to 2. 4. A method for measuring a crystal orientation of a crystal grain on a sample surface using an electron beam backscattering diffraction image or a Kossel diffraction image, and mapping the crystal orientation. The region where the systematic error occurs, which has a specific crystal orientation relationship between the measured correct crystal orientation and the incorrect crystal orientation, is defined as the misorientation angle of the measured crystal orientation with respect to the predetermined crystal orientation. The method according to claim 1 or 2, wherein the calculation is performed, a distribution of the misorientation angle on the sample surface is processed by a high-speed wavelet transform, and detection is performed by indicating a high frequency in a region limited by the high-speed wavelet transform. The crystal orientation measurement method described in the above.