JPH10197416A - Standard sample for luminous spectrochemical analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To analyze and grasp a content of each element of a sample to be analyzed and correctly estimate performance of metallic products of various kinds, by subjecting a molded body of a mixture of fine metallic bodies to a plastic deformation process. SOLUTION: A metallic body is specifically formed of an aluminum alloy containing Si by 12-25wt.%, a metallic body is a rapidly solidified body, and a standard sample is an aluminum molded body containing Si by 12-25wt.%. The mixed molded body thus formed is molded to a disk-like shape fit for luminous spectrothemical analysis. The molding should be accompanied with a plastic deformation, e.g. pressing, extrusion, rolling, forging or the like. The molding with the plastic deformation forges metallic bodies constituting the mixed body into a plastic flow and consequently turns the metallic bodies furthermore highly uniform. Particularly, when the extrusion is adopted during the plastic molding, a favorable result can be obtained because a face perpendicular to a flow of the metal at the mold time, namely, a cross section perpendicular to an extrusion direction can be selected as an analysis face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standard sample for emission spectroscopy having a uniform element content and a stable quality.

[0002]

2. Description of the Related Art In the analysis of the composition of metals, as a method capable of rapid analysis, the content of each element in a standard sample is determined from a calibration curve showing the spectral intensity ratio of the base metal to the content of each element. The specified emission spectroscopy has been applied to the analysis of various metals.

[0003] That is, in the emission spectroscopy, the spectral intensity ratio of a sample to be analyzed is embedded in a calibration curve drawn based on a standard sample prepared in advance, and the element content of the sample to be analyzed is calibrated. Therefore, the analysis accuracy and accuracy of the sample to be analyzed are the accuracy of the calibration curve prepared in advance and the accuracy of the correction of the daily drift of the calibration curve (fluctuation in the spectrum intensity ratio caused by the analyzer). Depends on Therefore, in order to perform an accurate analysis, a standard sample that is uniform and has a known element content is required.

In general, as a standard sample used for such emission spectroscopy, a metal melt containing a conventionally desired alloy component is cast into a mold and has a diameter of 40 to 60 mm.
A disk-shaped ingot with a thickness of 5 to 10 mm is used,
The amounts of the components are identified by chemical analysis to determine standard values, which are used as standard samples. In emission spectroscopy, such a standard sample is chamfered to a smooth plane, and a calibration curve is drawn from a spectrum intensity ratio generated by emitting light at a predetermined position in the plane.

However, when the molten alloy is solidified, as is generally the case, when a large amount of alloying elements is contained, the alloying elements tend to segregate in the solidified structure, and as a result, light emission Because the spectrum intensity differs depending on the difference in the plane or three-dimensional position to be
When such a sample is used as a standard sample, accurate analysis cannot be performed. Therefore, in order to minimize segregation during solidification of the molten alloy, the molten metal is solidified by using a water-cooled semi-continuous casting method as high as possible (the current semi-continuous casting method has a casting rate of about 10 ° C./sec. ) Is cast into a small-diameter cast rod, which is cut into a disk and used as a standard sample.

[0006]

However, as described above, segregation is not sufficiently eliminated even when the alloy is cast into a small-diameter cast rod, and this segregation becomes more remarkable particularly when the alloy element content of the sample is increased. Have a tendency. For example, in the case of an Al-Si alloy containing Si at a temperature higher than the eutectic point, primary crystal silicon is easily crystallized. Therefore, even when solidified by casting into a small-diameter cast rod by a semi-continuous casting method, crystallized. The calibration curve and its drift correction become unclear due to the segregation of primary silicon, and it is difficult to accurately analyze the sample to be analyzed.

An object of the present invention is to provide a standard sample for emission spectrometry capable of solving the above-mentioned conventional problems, obtaining an accurate calibration curve, and performing accurate drift correction. It is intended for.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted various studies to achieve the above object, and have found that a fine metal body is mixed and molded and used as a standard sample for emission spectral analysis. The effect of segregation of alloying elements, which causes analysis errors, is hardly recognized, so that accurate calibration curves can be drawn and accurate drift correction can be performed. Can be accurately analyzed, and the present invention has been completed.

That is, the present invention is characterized by a standard sample for emission spectroscopy comprising a mixed compact of a fine metal body, wherein the metal body is made of an aluminum alloy particularly containing 12 to 25 wt% of Si, and Is a rapidly solidified body.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The metal body in the present invention refers to fine powders, granules, pieces, stays, rods, fine wires, and the like. Therefore, even if there is some segregation between metal bodies, they are averaged when viewed as a whole analysis surface, and the three-dimensional location of the standard sample , A precise calibration curve can be drawn at the time of emission spectroscopy, accurate drift correction can be performed, and as a result, the element content of the sample to be analyzed can be accurately analyzed. .

Further, when the metal body is a rapidly solidified solid body, segregation is small in itself, so that a standard sample formed by mixing these can draw a more accurate calibration curve, and accurate drift correction is possible. In addition, the element content of the sample to be analyzed can be accurately analyzed.

Next, a method for producing a standard sample for emission spectroscopy according to the present invention will be described. In the present invention, the rapidly solidified fine metal body is formed by atomizing a molten metal, a crucible method with a rotating hole (rotating a crucible having a large number of pores on a side wall to scatter the molten metal as droplets, and drop droplets in the air or in water). Powder and granules obtained by rapid solidification, etc.), pieces, nights, rods, fine wires, etc. obtained by rapid solidification by single / twin roll method, underwater spinning method, etc. As described above, the rapidly solidified metal body obtained by directly or indirectly bringing the molten metal into contact with the cooling water can be used for casting at the time of casting.
From where high cooling rate such as ^{2 ~10 6} ℃ / sec is obtained, the metal body obtained by the coagulation not only less segregation, when by these rapid solidification, relatively casting hot melt Since there is little variation in the lot during the early and late stages of casting,
Using any part of the metal body, it is possible to obtain a standard sample having a very stable and uniform composition.

The rapidly solidified metal body obtained as described above is further converted into ultrafine powder using a cutter or a pulverizer and sufficiently mixed to form a homogeneously mixed molded body. Mixing may be performed using a usual mixer. In addition, when mixing, it is easiest to independently mix and mold a powder of a metal body having an alloy composition that matches the target standard sample, but two or more types including the metal component contained in the standard sample are used. Metal bodies having different compositions can be combined and mixed, or a metal body and a powder of a pure metal can be combined and mixed. For example, when it is desired to obtain a standard sample of an Al-Si-Cu-Mg-based alloy, a powder of an Al-Si-based, an Al-Cu-based, or an Al-Mg-based alloy is added to the Al-Cu-Mg-based alloy powder. The body may be mixed and molded at a predetermined mixing ratio, and a metal body of an Al-Cu-Mg alloy and a powder of a pure metal such as metallic silicon may be mixed at a predetermined mixing ratio and mixed and formed. Alternatively, pure metals may be mixed and formed. When a pure metal powder is selected, the pure metal does not necessarily need to take the form of the rapidly solidified metal body according to the present invention.

Next, the thus obtained mixed molded body is formed into a disk shape suitable for emission spectroscopic analysis. The forming involves plastic deformation such as pressing, extrusion, rolling and forging. Processing is good. This is because, by performing the processing accompanied by plastic deformation, the metal body itself forming the mixed molded body is forged in a plastic flow, so that the uniformity is further improved. In particular, when extrusion is employed during plastic working, favorable results can be obtained because the analysis surface can be selected as a surface perpendicular to the flow of the metal at the time of molding, that is, a cross section perpendicular to the extrusion direction for emission spectroscopic analysis.

[0015] In this extrusion process, the cross-sectional area of the original metal body in a cross section perpendicular to the extrusion direction decreases in accordance with the extrusion ratio, so that the number of the original metal bodies per unit cross-sectional area is reduced. This is because it is the same as increasing, and a more accurate calibration curve can be drawn, so that the composition of the sample to be analyzed can be accurately analyzed.

In order to increase the uniformity of the molded body by extrusion, it is preferable to increase the number of original metal bodies per unit area of the analysis surface. Therefore, it is preferable to select a metal body having a cross-sectional area as small as possible. Here, consider the case where a metal powder is extruded into a round bar with respect to the size of the metal body, cut at a right angle to the extrusion direction, and a disc-shaped standard sample is prepared. Is r, the extrusion ratio is R,
When the diameter of the effective emission spectrometer is 5 mm, the number n of the metal powders contained in the analyzer is approximately expressed by the following equation.

[0017]

N = (5 / r) ² · R Here, when the extrusion ratio is R = 25, when r = 5 mm,
n = 25, which is the same as taking the average of 25 samples even if there is some deviation in composition between the metal powders. In other words, when the extruding process is performed, the uniformity of the sample is much higher than in the case where the extruding process is not performed, so that the analysis can be performed with stable and high accuracy. This also makes it possible to prepare a sample without making the metal powder into an ultrafine powder having a high risk of dust explosion, for example, 60 μm or less, which is extremely advantageous in terms of work safety management. Becomes

The plastic working of the mixed molded body may be performed by rolling, forging, or the like in addition to extrusion, but also in this case, a plane perpendicular to the plastic flow direction of the alloy should be used as the analysis plane. It is advantageous. However, the surface is large enough to repeat the analysis a plurality of times, that is, 40 to 60 m.
In order to achieve a thickness of m, large-scale processing is required, and because it is not economical, analysis is usually performed on a plane parallel to the direction of plastic flow of the metal. In such a surface, since the metal body has a long and elongated structure, the number of original metal bodies per unit area is reduced as compared with the case of extrusion processing, and the uniformity of the sample is slightly inferior. However, in this case, a metal body having a smaller size may be selected. In any case, the standard sample for emission spectroscopy of the present invention obtained by performing plastic working is far more than a disk-shaped ingot sample obtained by conventional die casting or water-cooled continuous casting. There will be no change in the uniformity.

In the present invention, the size of the metal body of the compact obtained by quenching casting is 5 mm or less, preferably 3 mm or less in the case of powder or granules, and 1 mm in the case of pieces or foil. In the case of a rod, a thin wire, or the like, the diameter is preferably 5 mm or less, and more preferably 3 mm or less. However,
For example, an extremely fine metal body such as an ultrafine powder having a diameter of 0.6 μm or less involves a risk of explosion, so it is better to avoid it from the viewpoint of safety management.

The composition of the metal body in the present invention is not particularly limited as long as it contains a metal contained in the metal composition of the target standard sample. Especially when the composition of the metal body is adjusted to the composition of the standard sample itself, for example, when the standard sample is an aluminum alloy, elements such as Ti and Fe which are easily segregated upon solidification of the alloy have a peritectic point or a eutectic point or higher. Al-12-25w containing silicon above the eutectic point, which is easy to crystallize containing alloys and primary silicon
The present invention is particularly effective when producing a standard sample having a composition such as a t% Si-based alloy. Of course, it is clear from the above description that an aluminum alloy containing 12 wt% or less of Si has an excellent effect.

In addition, Pb and Bi which are apt to cause gravity segregation
Also, the present invention exerts excellent effects in the production of Al-Pb (Sn) -based alloys containing Al and the like, and the production of standard samples of Al-Ti-B-based alloys which are liable to cause agglomeration of crystallized substances. Other Cu, Z
Al-Cu-Mg alloy containing n, Mg, etc. or Al
-For multi-element alloys such as Cu-Mg-Zn alloys, of course, obtain a standard sample by plastically processing a mixed compact obtained by rapidly solidifying a molten alloy having a composition that matches the composition value of the standard sample. Al-Cu alloy, Al-M
A plurality of metal bodies having different compositions such as a g-based alloy and an Al-Zn-based alloy are prepared, mixed with a target standard sample composition, and then subjected to plastic working on the mixed molded body. Can be used as a standard sample containing the same composition uniformly, and it is also possible to adjust the alloy composition by further adding pure metal powder to a metal body of an alloy having any of these compositions.

When a sample to be analyzed having a different metallurgical history from the sample using the standard sample for emission spectroscopy according to the present invention is subjected to emission spectroscopy, particularly, the same Si content is determined depending on the size of primary crystal Si grains. Since the spectral intensity ratio of Si differs depending on the amount, it is necessary to perform preliminary measurement in advance to determine the degree of the effect and to grasp and correct it (JISH1).
305).

[0023]

EXAMPLES Examples of the present invention will be described below together with comparative examples. Example 1 JIS AC9B alloy (composition: Al-18.9 wt% S
i-1.4 wt% Cu-10 wt% Mg-1.2 wt%
Ni-0.4 wt% Fe) (calculated value of blending) at 850 ° C.
The molten metal is sprayed by rotating a crucible with a hole, and cooled in water to 10 ² to 10 ³ ° C / sec.
At a cooling rate of 0.8 mm in average particle size (particle size range 0.3 to
3 mm) was prepared. This metal body was sufficiently mixed, filled in a bottomed can having an inner diameter of 100 mm and a length of 150 mm, and the can was extruded to obtain a round bar having a diameter of 40 mm.
This round bar was cut into a disk shape by cutting each 50 mm in length, and a plane perpendicular to the extrusion direction was chamfered to obtain a standard sample for emission spectroscopy. Emission spectroscopy was performed on this sample.

Emission spectroscopy was performed under the following conditions. Emission method: High pressure spark method Emission atmosphere: Atmosphere Counter electrode: Graphite rod Working wavelength: Si 390.55 nm Al 256.80 nm (internal standard line) Analytical element: Si Analysis position: Perpendicular to the extrusion direction every 50 nm in the length direction Central part (within 1/2 radius) and outer peripheral part (equal position outside 1/2 radius) in plane

The analysis of one sample was performed five times on the same plane. FIG. 1 shows the analysis results. Each point in FIG. 1 is an average value of the above five measurements. In addition, a standard deviation value σ of 10 times in total of 5 times each of the number of measurements of the central portion and the outer peripheral portion in each sample.
The value of _n-1 was 0.11 to 0.16 wt%.

From the results shown in FIG. 1, the analytical values are between 18.7 and 19.0 wt% despite the high Si content, and the fluctuation range of the analytical values depending on the analytical position in the extrusion direction is small and the same. The value of the surface standard deviation σ _n-1 is 0.11
Since the variation is small at about 0.16 wt%, segregation due to the difference in position is small, and it is understood that the composition is suitable as a standard sample for emission spectrometry.

Example 2 The granular metal body prepared in Example 1 was pressed with a 600 t press to obtain a pressed rod having a diameter of 40 mm and a length of 100. This press bar was cut into 50 mm length pieces to obtain a disk shape, and a plane perpendicular to the length direction was chamfered to perform emission spectroscopy as a standard sample for emission spectroscopy.
Emission spectroscopy conditions were the same as in Example 1.

As a result of the analysis, the average value of the central five points was 18.
8 wt%, the average value at 5 points on the outer peripheral portion was 19.0 wt, and the value of the standard deviation σ _n-1 at 10 analysis points was 0.19 wt%. From this result, the fluctuation width of the analysis value is small, and the variation of the value of the standard deviation σ _n−1 of the same surface is small.
It can be seen that segregation due to the difference in position is small, and that it is suitable as a standard sample for emission spectral analysis.

COMPARATIVE EXAMPLE 1 As a comparative material, a high-silicon Al-Si alloy (Al-16.5 wt% Si-4.7) which is an A390 equivalent alloy of AA standard was used.
wt% Cu-0.55wt% Mg-0.3wt% F
e) and low silicon Al-Si alloys (Al-14.
6wt% Si-0.46wtCu-0.5wt% Mg-
0.3 wt% Fe) (all calculated values of blending)
C. and cast into a mold having a disk-shaped cavity having a diameter of 55 mm and a thickness of 10 mm to obtain a mold casting. The cooling rate of the molten metal at this time was 0.5 to 3 ° C / sec. Next, a plane perpendicular to the central axis of the cast material was chamfered to obtain a standard sample, and emission spectroscopy was performed on this sample.

In the measurement by the emission spectroscopy, the analysis position was taken as the outer peripheral portion of a plane perpendicular to the central axis, and the analysis of one sample was measured five times on the same plane. The other conditions were the same as those in Example 1. The analysis results are shown in FIGS. Each point in FIGS. 2 and 3 is an average value of the above five measurements.

The analytical value of the high silicon Al-Si alloy shown in FIG. 2 is between 16.2 and 17.4 wt%, segregation due to a change in the position in the thickness direction is large, and in the same plane. The value of the standard deviation value σ _n-1 (n = 5) is 0.18-0.
Since it is as large as 47% by weight, it is understood that it is not suitable as a standard sample for emission spectroscopy.

The analytical value of the low silicon Al-Si alloy shown in FIG. 3 is between 14.1 and 15.0 wt%, and segregation due to a change in the position in the thickness direction is large, and within the same plane. Of the standard deviation σ _n-1 (n = 5) of 0.12 to
Since it is as large as 0.31% by weight, it is understood that it is not suitable as a standard sample for emission spectroscopy.

Comparative Example 2 As a comparative material, high silicon A of an A390 equivalent alloy of AA standard was used.
l-Si alloy (Al-15.5wt% Si-4.7w)
t% Cu-0.55wt% Mg-0.3wt% Fe)
(Calculated value) was melted at 750 ° C., and a cast rod having a diameter of 58 mm was obtained by a water-cooled semi-continuous casting method, used as a standard sample, and subjected to emission spectroscopic analysis. At this time, the cooling rate of the molten metal during the casting of the casting rod is 5 to 10 ° C./sec.
c.

In the measurement by the emission spectroscopy, the analysis position is determined by setting the center part (within 1/2 radius) of the plane perpendicular to the casting direction and the outer peripheral part (equal position outside of 1/2 radius) in the length direction to 1000 points.
The measurement was performed under the same conditions as in Example 1 except that the analysis of one sample was performed five times for each of the central part and the peripheral part on the same plane. FIG. 4 shows the analysis results. Each point in FIG. 4 is an average value of the above five measurements. In addition, the value of the standard deviation σ _n-1 (n = 10) of 10 times, which is the total of the number of times of each measurement of the central portion and the outer peripheral portion in each sample, was 0.5 to 1.0.

From the results shown in FIG. 4, the analytical values are 15.0 to 1
It is between 6.2 wt%, and the segregation due to the difference in the analysis position in the casting direction in the thickness direction is large, and the standard deviation value σ _n-1 (n = 5) in the same plane is 0.1%. 5-1.
Since it is as large as 0 wt%, it is understood that it is not suitable as a standard sample for emission spectroscopy.

[0036]

As described above, the standard sample for emission spectroscopy according to the present invention has a uniform element content and a stable quality, so that the element content of the sample to be analyzed can be accurately analyzed. Since it can be grasped, the performance of various metal products or semi-finished products can be accurately predicted or grasped.

[Brief description of the drawings]

FIG. 1 is a diagram showing the results of emission spectroscopy analysis of a standard sample according to the JIS AC9B alloy according to the present invention. FIG. 1 (a) is a diagram showing analysis values, and FIG.

FIGS. 2A and 2B are diagrams showing the results of emission spectroscopic analysis of a high silicon Al-Si alloy standard sample cast by a mold casting method, wherein FIG. 2A shows an analysis value and FIG. 2B shows a standard deviation value. .

3A and 3B are diagrams showing the results of emission spectroscopy analysis of a low silicon Al-Si alloy standard sample cast by a mold casting method, wherein FIG. 3A shows an analysis value and FIG. 3B shows a standard deviation value. .

FIG. 4 shows A390Al- cast by a water-cooled semi-continuous casting method.
It is a figure which shows the result of emission spectroscopy analysis using the Si alloy casting rod as a standard sample, (a) is an analysis value, (b) is a figure which shows a standard deviation value.

[Procedure amendment]

[Submission date] February 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

That is, in a first embodiment of the present invention , a process involving plastic deformation is applied to a mixed compact of a fine metal body.
And characterized in emission spectroscopy for the standard sample of Te, becomes the metal body is a particularly Si aluminum alloy containing 12～25Wt%, also the metal body is a rapid solidification body, further wherein the standard sample Si is 12 ~ 25wt
% Of aluminum molded body
And in a second embodiment, a quenched solid.
Of fine metal bodies containing 12 to 25 wt% of Si.
Luminium mixed molded body is subjected to processing accompanied by plastic deformation
The standard sample for emission spectroscopy is characterized in that:

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Next, the thus obtained mixed molded body is formed into a disk shape suitable for emission spectroscopic analysis. The forming involves plastic deformation such as pressing, extrusion, rolling and forging. Processing must be performed. This is because, by performing the processing accompanied by plastic deformation, the metal body itself forming the mixed molded body is forged in a plastic flow, so that the uniformity is further improved. In particular, when extrusion is employed during plastic working, favorable results can be obtained because the analysis surface can be selected as a surface perpendicular to the flow of the metal at the time of molding, that is, a cross section perpendicular to the extrusion direction for emission spectroscopic analysis.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsumi Takahashi 1-34-1 Kambara, Kambara-cho, Anbara-gun, Shizuoka Prefecture Nikkei Giken Co., Ltd.

Claims (4)

[Claims] 1. A standard sample for emission spectroscopy characterized by comprising a mixed compact of a fine metal body. 2. The standard sample for emission spectroscopy according to claim 1, wherein said metal body is made of an aluminum alloy. 3. The standard sample for emission spectroscopy according to claim 2, wherein said metal body is made of an aluminum alloy containing 12 to 25 wt% of Si. 4. The standard sample for emission spectroscopy according to claim 1, wherein said metal body is a rapidly solidified body.