JPS6010154A - Sample holding method and sample holder for analysis of metal surface - Google Patents

Abstract

PURPOSE:To prevent a short-circuit, by a method wherein a container having an opening part provided to the central part of the smooth surface thereof is brought into close contact with the back surface side of a sample metal plate to be analyzed and discharge is performed in such a state that the container is evacuated to allow the sample metal plate to be sucked to the aforementioned opening part. CONSTITUTION:A sample metal plate 13 is contacted with the opening part 15 provided to a vacuum container 14 in a pierced state and an O-ring 16 is provided to the opening part 15 in order to bring the sample metal plate 13 into close contact with said opening part 15 and to keep air-tightness. In the next step, discharge is performed in such a state that the vacuum container 14 is evacuated to allow the sample metal plate 13 to be sucked to the aforementioned opening part 15. By this constitution, in analyzing the surface film of the thin sample metal plate by a glow discharge light emitting spectroscopic analytical apparatus, measurement can be performed without a short-circuit while an electrode interval is properly kept.

Description

Detailed Description of the Invention (Field of Application) The present invention provides a method for holding a sample for metal surface analysis, which can hold the analysis surface smooth when analyzing the surface layer of a metal sample plate by glow discharge emission spectroscopy. The present invention relates to the holder.

(Prior Art) In recent years, there has been a demand for various surface treatments on metal materials to improve the properties of the materials such as corrosion resistance. Since the quality of surface treatment depends on the condition of the surface layer of the material,
Correspondingly, from the perspective of materials research, it has been recognized that it is necessary to analyze the surface layer and provide appropriate information for setting manufacturing process conditions. The above-mentioned surface layer has a thickness ranging from several amps to about 1 μm, and is mainly an oxide film (for example, iron, manganese, etc.) formed on the outermost surface of the material.
refers to oxides of silicon, aluminum, etc.

Currently, there are various types of equipment that can perform surface analysis such as the state and composition of films in the angstrom to micron range, but glow discharge emission spectroscopy is a method for quickly examining the state of the metal material itself and the film after surface treatment. (Gl
ow -Discharge OpticalEmis
sion 5 pectroscopy, hereinafter abbreviated as GDS]. G]) S is characterized by the ability to quickly investigate the composition distribution in the depth direction from the outermost surface layer of a wide range of coatings and the average composition of the coating. first,
Let me explain a little about GDS.

In GDS, the surface of a metal sample plate is bombarded by argon ions generated at the anode of a glow discharge tube, and is regularly eroded in layers starting from the surface layer. The fine particles eroded from the sample surface are fed into the plasma generated by the glow discharge, are excited in an atomic state, and emit characteristic spectral lines of their constituent elements. Therefore, the composition of each layer can be determined by dividing the plasma light of the glow discharge using a diffraction grating or the like and measuring the intensity of the characteristic spectrum line using a photomultiplier tube.

As shown in Fig. 1, the discharge tube has a diode-type configuration, and the anode 1 and the cathode 8 with the water cooling conduit 7 are each made of a partial block of Cu-Co-Be with good thermal conductivity. , are insulated from each other by a Teflon plate 4 having a thickness of 0.2 mm. The sample 5 is mechanically pressed against the cathode block by a support 12 together with a pressing plate 6 having a water cooling conduit 7, thereby sealing the discharge tube 5 and isolating it from the outside air, and at the same time forming part of the cathode. A hollow cylindrical anode tube 2 with a quartz window 11 penetrates the cathode block, and the sample 5 (!: 0.
They face each other with an interval of 2 mm. The tube is evacuated in stages by two evacuation systems 3 and 9, argon gas is introduced into the discharge tube through the gas inlet 10, the argon pressure is maintained at several Torr, and a DC voltage of about 1000 V is applied between the two electrodes to generate a glow discharge.

(Problem) Now, when analyzing the surface of a metal sample plate using GDS,
If the sample is thick and has sufficient rigidity, no problems will occur, but the metal composition and thermal history may be affected.

Insufficient rigidity due to thickness etc. causes problems.

For example, when the thickness of a mild steel plate is approximately 0.3 mm or less,
The part of the sample plate to be sputtered is sucked into the electrode (anode) side, and as mentioned above, since the gap between sample plate A and the anode is very narrow (0.2 am), a short circuit occurs, causing an abnormal discharge and preventing normal measurement.・ cannot be done. Therefore, the present inventors set 0:
The following several sample holding methods were tried when measuring metal materials with a diameter of 3 mm or less. That is, (1) A back plate with a thickness of 1 mm or more is placed on the metal sample plate to be measured, and both are fixed and reinforced with adhesive to prevent suction into the anode side. In this method, if the discharge is performed for a relatively long period of time, even if the cooling plate is applied to the outside of the back plate, the temperature will locally rise, causing the sample to peel off at the adhesive part and be sucked into the anode side.

(2) Measurement A metal sample plate (limited to ferromagnetic materials) is fixed by adsorption with a strong magnet, and measurement is performed. In this case, even with a strong magnet, the thinner the metal sample plate is, the weaker the coercive force becomes, and the attractive force on the anode side is greater, causing a short circuit and preventing normal discharge.

As mentioned above, it was difficult to measure when using a thin metal sample plate of approximately 0.3 mm or less.

(Structure of the Invention) In view of the above-mentioned problems when performing surface analysis of a metal sample plate due to GDSI, the present invention provides that the suction force on the vacuum vessel side is equal to or higher than the suction force on the glow discharge tube side. To provide a method and a holder for holding a sample, which allows a sample plate to be attracted to the sample plate, maintains an appropriate electrode spacing, prevents short circuits, and enables measurement.

Hereinafter, the present invention will be further explained in detail with reference to the drawings.

FIG. 2, FIG. 3, and FIG. 4 are explanatory diagrams of the non-inventive notes.

An opening 1 passing through the metal sample plate 13 and the vacuum container 14
5+ Koiteru. The opening 15 is in close contact with the metal sample plate 13,
An O-ring 16 is installed to maintain airtightness. Since this opening 15 is an important point of the present invention, it will be described in more detail.

■ GDS glow discharge tube (generally discharge diameter is 13 mmφ
)' If the degree of vacuum is, for example, 1 to 3 Torr (generally (measurements are performed at this degree of vacuum),
It is necessary to make the degree of vacuum at the opening 15 of the vacuum container 14 greater than that, so that the glow discharge tube does not get sucked in. That is, the adhesion force f on the vacuum vessel side and the attraction force f2 on the glow discharge tube side have the following relationship.

/, =S,X(760-V,), f2=S2X(76
0-V2) f1≧12 fl: Adhesive force on the vacuum vessel side, f2 Lid force on the Nigero discharge tube side S1+82: Effective opening area 1 v, l v2: Degree of vacuum However, before setting the metal sample plate to the glow discharge tube. However, if the electrodes were sucked into the vacuum vessel and deformed, it would not be possible to obtain an appropriate distance between the electrodes, so the shape was made with multiple holes instead of one large hole, and the opening area was the same as that of the glow discharge tube. diameter or a larger diameter to prevent deformation due to suction.

- The surface of the metal sample plate 13 at the opening must be smooth so that it does not become uneven. That is, unless the sample plate is smooth, airtightness with the glow discharge tube cannot be maintained, and glow discharge will not occur. Further, in order to maintain airtightness between the vacuum container 14 and the metal sample plate 13, an O-ring 16 was provided around the outer periphery of the opening 15. It is necessary to process a groove in this O-ring so that it is flush with the smooth surface of the opening 15. In other words, if the O-ring protrudes above the smooth surface, a step will be created between the O-ring and the opening, causing wrinkles in the metal sample plate 13 and making it impossible to maintain airtightness.

The three-way valve 18 is opened via the evacuation pipe 17, and the inside of the vacuum container 14 is evacuated by the vacuum pump 19. The cooling container silver is provided for cooling the glow discharge tube s during measurement using the vacuum container 14. This is not an integral part, and a method in which the cooling plate is brought into contact with the vacuum vessel 14 as in the above-mentioned GDS may also be used, but the above method has a better cooling effect,
Moreover, it is easy to operate. A two-way valve 22 is opened to allow water to constantly flow through the cooling pipe 21. Usually, tap water is used, but the cooling temperature should be as low as possible, and a refrigerant outside the water plate may also be used. In order to fix the vacuum container 14 and the cooling container side, a fixing device is inserted between the two, and fixing 01J rings 24 are installed on both sides so that each can maintain airtightness. Next, fix the fixture Z3 using the bolt 6.

Note that the exhaust pipe 17, three-way valve 18, vacuum pump 19. The structure consisting of the vacuum vessel 14 excluding the cooling tube 21 and the two-way knob 22 and the bolt 25 is referred to as the holder main body of the present invention.

The above is a detailed description of the present invention, and further details will be given with reference to examples.

(Example) The thickness of the film is 2000~! An example of analysis of the oxide film on a 300 OA thin cold-rolled steel sheet will be described. Metal sample plate 13
(30 x 30 x 0.2 mm each) is placed in the vacuum container 14 as shown in FIGS. 2 and 3. The shape of the trench and the holder body is 30φ x 35mm, and the material used is brass considering its workability, 4-electricity, and thermal conductivity. Vacuum container 14
The diameter of the opening 15 was 14 mm, and 40 through-holes with a diameter of 14 mm were drilled therein to give a hole area ratio of about 40%.

This smooth surface should be polished to ≠400, and 0 ring 1
No. 6 used had an inner diameter of 14 mmφ and a wall thickness of 2.2 mm. Next, the three-way valve 18 is opened from the evacuation pipe 17 in FIG. is suctioned and fixed to the opening 15. The two-way valve 22 is opened and water is allowed to flow through the cooling pipe 21 of the cooling container shown in FIGS. 2 and 4 to cool the entire container.

Next, the surface of the metal sample plate 13 fixed to the vacuum container 14 of the holder main body is brought into close contact with the cathode surface of the GDS.

The support 12 of the GDS shown in FIG. 1 is pressed against the center of the cross section of the cooling container shown in FIG. 4 to support it.

The glow discharge conditions are as follows: applied voltage: about 800 V, applied current: near 5 mA, and sputtering is performed from the outermost surface of the metal sample plate 13 in the depth direction in constant current mode.

Under the above conditions, the change in strength of iron from the surface film to the iron matrix was measured, including comparisons with the conventional back plate adhesive method and with only the sample plate. The results are shown in Table 1. As can be seen from the table, the present invention has measured the state in which the strength of iron changes sequentially in reeds from the iron oxide film on the surface to the iron matrix.

In the conventional method, the discharge was unstable because the sample plate was attracted and deformed, and the anode of the glow discharge tube and the sample were short-circuited midway through, making discharge impossible.

Table I: Strength value (m) of a thin cold-rolled steel sheet in the depth direction from the outermost surface of a thin cold-rolled steel sheet based on GDS1: The breaker is activated due to a short circuit, and the discharge stop unit is two counts (Arb, u0). According to the invention,
When analyzing the surface film of a thin metal sample plate using the Darrow discharge emission spectrometer, it is possible to maintain an appropriate electrode spacing without causing short circuits. Therefore, the present invention greatly contributes to the development of metal materials and surface treatment methods.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the GDS gummy discharge tube,
FIG. 2 is an explanatory diagram of the present invention, FIG. 3 is an explanatory diagram of a method for installing a vacuum container section and a metal sample plate, and FIG. 4 is an explanatory diagram showing the relationship between a cooling container section and a glow discharge tube. l... Anode, 2... Anode tube, 3, 9... Vacuum exhaust system, 4... Teflon plate, 5... Sample, 6... Pressing plate, 7... Water cooling Conduit, 8... Cathode, 10.
...Gas inlet, 11...Quartz window, 12...Support, 13...Metal sample plate, 14...Vacuum container, 15...
・・Opening part, 16・0νn closing, 17・Exhaust pipe, 18・3-way valve, J9・Vacuum pump, addition・
...Cooling container, 21...Cooling pipe, 22...2-way valve, n...Fixing tool, Sae...Fixing O-ring, 5.
...Volt, 26...Glow discharge tube. Patent applicant Representative patent attorney Tomoyuki Yafuki (and 1 other person) Procedural amendment (voluntary) August 1980//Japanese Patent Office Commissioner Kazuo Wakasugi 1 Indication of case Patent Application No. 116984 1988 2 , Name of the invention Sample holding method and holder for metal surface analysis 3, Person making the amendment/Relationship with 11 cases Applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name (6
65) Nippon Steel Corporation 4, Agent 5, Claims column 6 of the specification subject to amendment, Contents of the amendment (1) The statement of claims on page 1 of the specification was changed to the following: Correct as expected. (1) When analyzing the surface layer of a metal material by glow discharge emission spectroscopy, on the back side of the metal sample plate to be analyzed,
A container having an opening in the center of a smooth surface is brought into close contact with the container, the inside of the container is evacuated, a metal sample plate is adsorbed to the opening, and the container is fixed to a glow discharge tube and a discharge is caused. A method for holding samples for metal surface analysis.

Claims (2)

[Claims] (1) When analyzing the surface layer of a metal material by glow discharge emission spectroscopy, a container with an opening in the center of the smooth surface is tightly attached to the back side of the metal sample plate to be analyzed, and the inside of the container is A method for holding a sample for metal surface analysis, characterized by vacuum evacuation (a metal sample plate adsorbed to the opening is fixed to a glow discharge tube and discharged). (2) A sample adsorption aperture with a plurality of holes in the medium heat part of the smooth surface, which is used when analyzing the surface layer of a metal material by glow discharge optical emission spectroscopy, and A sample holder for surface analysis of gold scraps, characterized by comprising an exhaust port for creating a vacuum inside during communication and adsorption of a sample, and a cooling section for preventing a rise in temperature of the sample.