JP2000144380A - Super corrosion resistant alloy and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a super corrosion-resisting alloy composed of amorphous or nano-crystalline alloy having super corrosion resistance capable of resisting even concentrated acids by the use of an inexpensive base material of sputtering target. SOLUTION: This super corrosion-resisting alloy has a composition consisting of, by atom, 7-87% of at least one element among Ta, Nb, Zr, and Ti, 5-87% of at least one element among Cr, Mo, and W, and the balance <=75% Ni or Fe and Ni. The super corrosion-resisting alloy is manufactured by the sputtering method using a target prepared by using a non-magnetic commecial alloy as a base material 4 of target and setting or embedding small pieces 5, 6 of additive elements on or in the base material 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to concentrated hydrochloric acid, concentrated sulfuric acid,
The present invention relates to a super-corrosion-resistant alloy capable of withstanding a severe corrosive environment such as concentrated nitric acid and a method for producing the super-corrosion-resistant alloy by a sputtering method.

[0002]

2. Description of the Related Art As an amorphous alloy capable of withstanding the severe corrosiveness of concentrated acids such as concentrated hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid, Japanese Patent Application Laid-Open No. 61-210143 discloses Ta-Ni, Ta-Ni.
(Fe, Co) -Ni, Ta- (Ti, Nb, W) -N
i, Ta- (Ti, Nb, W)-(Fe, Co) -Ni
Zr-Ni is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 3-72055.
Zr-Nb-Ni, Zr- (Ti, W, Ta) -Ni,
A Zr-Nb- (Ti, W, Ta) -Ni alloy is disclosed in JP-A-5-105996 and JP-A-5-222495, and a (Ta, Nb) -Cr alloy is disclosed in
JP-A-266549 discloses a Ta-Fe-Ni-Cr alloy.

[0003] In these alloys, Ta, Nb, Zr, and Ti, which are collectively referred to as valve metals, are contained as elements responsible for corrosion resistance. Further, as disclosed in JP-A-5-105996 and JP-A-5-222495, by alloying Cr with this valve metal, an order of magnitude larger than that of a single element of any of the elements constituting the alloy is obtained. On the contrary, high corrosion resistance can be realized.

In the past, these alloys were produced by a liquid quenching method. However, as in the case of a Ta—Cr alloy, the melting point of one element constituting the alloy is higher than the boiling point of another alloy element, and the The sputtering method is applied to those which cannot be produced by the method.

[0005]

As described above, an alloy containing valve metal and Cr has remarkably high corrosion resistance. However, both valve metal and Cr have a certain size as a base of a sputtering target. Things are difficult or expensive to make. Therefore, valve metal and Cr
Despite the extremely high corrosion resistance of a corrosion-resistant alloy containing, it is difficult to manufacture, or a very expensive single-metal target base may be used, or a small piece of an alloy element may be placed on this target base. Since it is manufactured by embedding or applying a sputtering method, it is not easy to put it into practical use in terms of cost and the like.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a super-corrosion-resistant alloy which can be easily produced by a sputtering method using an inexpensive target substrate, and a method for producing the same.

[0007]

According to the present invention, there is provided a super-corrosion resistant alloy comprising one or more elements selected from the group consisting of Ta, Nb, Zr and Ti: 7 to 87 atomic%, Cr, M
one or more elements selected from the group consisting of o and W: 5 to 87 atomic%, and the balance is substantially 75 atomic% or less of Ni or a super-corrosion resistant alloy of Fe and Ni, And an amorphous alloy or a nanocrystalline alloy produced by a sputtering method using a nonmagnetic metal or alloy as a target substrate.

This super-corrosion resistant alloy is easily formed by a sputtering method in which a commercially available non-magnetic metal or alloy is used as a target base, and a predetermined additive element is mounted on or embedded in the target and a predetermined alloy structure is formed. Can be manufactured.

That is, the present inventors have studied the properties of amorphous alloys for many years and found that Ta, Nb, Zr, Ti
Amorphous or nanocrystalline alloys composed of at least one kind of valve metal such as, for example, and one or more kinds of Cr, Mo, W can be produced by a sputtering method. Have also been found to exhibit extraordinarily excellent super corrosion resistance in various acids including concentrated hydrochloric acid. However, conventionally, in the production of these super-corrosion-resistant alloys, these expensive single metals are used as target bases, and small pieces of alloy elements are mounted or embedded in the target bases and used as targets. Was.

The inventors of the present invention have conducted repeated studies to produce a super-corrosion-resistant alloy by such a sputtering method at a lower cost and more easily. As a result, Cr and Mo were contained in stainless steel and a corrosion-resistant Ni alloy. There are a large number of such alloys, and even if these are used as components in the target substrate as Cr and Mo sources of the super-corrosion-resistant alloy, it is possible to produce an amorphous or nano-crystalline alloy having super-corrosion resistance. The present inventors have found that the substrate is much cheaper than using a single metal as the target substrate, and have completed the present invention.

The method for producing a super-corrosion-resistant alloy of the present invention is a method for producing such a super-corrosion-resistant alloy of the present invention by a magnetron sputtering method, and includes a nonmagnetic austenitic stainless steel, an iron-based superalloy or Cr. An Ni alloy is used as a target substrate, and a target in which one or two or more required amounts selected from the group consisting of Ta, Nb, Zr and Ti are placed or embedded in a sputter erosion region of the substrate is used. A magnetic austenitic stainless steel, an iron-based superalloy or a Ni alloy is used as a target substrate, and one or two or more selected from the group consisting of Ta, Nb, Zr, and Ti, and Cr, Mo in a sputter erosion region of the substrate. And embedding or embedding the required amount with one or more selected from the group consisting of It is characterized by using as Tsu bets.

[0012]

Embodiments of the present invention will be described below in detail.

The alloy composition of the super-corrosion resistant alloy of the present invention is as shown in Table 1 below.

[0014]

[Table 1]

The reasons for limiting the composition of each component in the super-corrosion resistant alloy of the present invention will be described below.

The alloy having super corrosion resistance must contain at least one of Ta, Nb, Zr, and Ti as valve metals and at least one of Cr, Mo, and W as corrosion metals. If the addition amount of both metals is small, sufficient corrosion resistance cannot be obtained, so one or more of Ta, Nb, Zr, and Ti must be at least 7 atomic%, and one or more of Cr, Mo, and W must be at least one. 5 atomic% or more is required. Further, in order to guarantee corrosion resistance, at least one of Ta, Nb, Zr, Ti and Cr, M
Since the total of at least one of o and W is required to be 25 atomic% or more, the total of the substantially remaining Fe and Ni or Ni is 7%.
Must be 5 atomic% or less. On the other hand, Ta, N
If one or more of b, Zr, and Ti and one or more of Cr, Mo, and W are too large, the alloy does not become an amorphous alloy, and a single metal phase having a crystal grain size of 100 nm or more precipitates. Super corrosion resistance cannot be obtained. Therefore, Ta, N
One or more of b, Zr, and Ti must be 87 atom% or less in total, and one or more of Cr, Mo, and W must be 87 atom% or less in total.
It must be less than atomic%.

Next, a method for producing the super-corrosion-resistant alloy of the present invention for producing such a super-corrosion-resistant alloy by a magnetron sputtering method will be described with reference to FIG.

FIG. 1A is a configuration diagram showing an embodiment of a sputtering apparatus used for producing a super-corrosion resistant alloy according to the present invention, and FIG. 1B is a perspective view showing details of a target holding section. . 1 (a) and 1 (b), 1 is a target assembly, 2 is a substrate, 3 is a vacuum vessel, 4 is a target base, 5 and 6 are small pieces of additive elements, 7 is a copper backing plate, 8, 9 are magnets, Reference numeral 10 denotes a target holder.

Immediately above the magnet 8 is a sputter erosion region of the target, and the additional element small pieces 5 and 6 placed in this region, and the exposed surface of the target base 4 which is not covered by the small pieces and whose surface is exposed. Ions collide with the substrate 2 and sputtered elements accumulate on the rotating and revolving substrate 2 to obtain an alloy. Target substrate 4
Are in close contact with the copper backing plate 7 and are water-cooled via the copper backing plate 7. The substrate 2 is also water-cooled.

In the present invention, when producing an alloy by such a magnetron sputtering method, a nonmagnetic austenitic stainless steel, an iron-based superalloy, or a Ni alloy containing Cu is used as a base, and Ta, Ta is added to its sputter erosion region.
A target in which at least one of Nb, Zr, and Ti is mounted or embedded in a required amount is used as a target. As a result, one or more of Ta, Nb, Zr, Ti and Cr
Can be produced. Alternatively, a nonmagnetic austenitic stainless steel, an iron-based superalloy or a Ni alloy is used as a base, and Ta,
Any one or more of Nb, Zr, Ti and Cr, Mo, W
A target in which at least one of them is loaded or embedded in a required amount is used as a target. Thus, an alloy containing one or more types of Cr and Mo can be produced using the substrate as a Cr and Mo source.

For example, when a sputtering method is applied using 304 stainless steel as the target substrate 4 and using Ta as the additive element small piece 5 and Cr as the additional element small piece 6, Fe-
A Cr-Ni-Ta alloy is obtained. In this case, the concentration of Ni with respect to Fe is the same as that in 304 stainless steel, but the concentration of Cr with respect to Fe is higher than that in 304 stainless steel by the amount of the added element small pieces 6, and the T concentration with respect to Fe is small.
The concentration of a is determined by the area of Ta of the additive element small piece 5. Therefore, the obtained alloy composition is determined by the relative area between the target substrate 4 and the small additional element pieces 5 and 6 in the sputter erosion region. Therefore, the target substrate 4
By changing the type and the number of the additional element pieces 5 and 6, alloys having various compositions can be arbitrarily manufactured.

It should be noted that Co, Si, Al, and Mn naturally mixed from the commercially available alloy used for the target substrate do not interfere with the object of the present invention.

[0023]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1 A commercially available 304 stainless steel having a diameter of 100 mm and a thickness of 6 mm was used as a target substrate, and six pieces of 99.9% pure Ta having a diameter of 20 mm and a thickness of 2 mm and a diameter of 20 mm and a thickness of 2 were used.
An alloy was prepared by applying the magnetron sputtering method shown in FIG. 1 to a target in which two pieces of Cr having a purity of 99.9% and having a thickness of 99.9% were respectively placed on a target substrate in a sputter erosion region.

When the obtained alloy was analyzed by EPMA (electron probe microanalysis), it was found to be Fe-32 atomic% Cr-4 atomic% Ni-40 atomic% Ta alloy.
X-ray diffraction revealed that this alloy was an amorphous single-phase alloy.

The obtained alloy was immersed in 12M hydrochloric acid at 30 ° C. for 1 week, and no decrease in the weight of the alloy due to corrosion was detected by microbalance. In addition, electrochemical measurements revealed that the alloy was self-passive covered with a stable passivation film in 12 M hydrochloric acid at 30 ° C., indicating that the alloy has super-corrosion resistance. Proven.

Example 2, Comparative Example 1 In the same combination as in Example 1, Ta was added without adding small Cr pieces.
When the number of small pieces was changed, and when the number of further small Cr pieces was added (however, in Comparative Example 1, no Cr small piece or Ta small piece was used), an alloy was produced in the same manner as in Example 1. Performed, obtained alloy composition, structure, 30 ℃ 12M
Table 2 shows the results of immersion in hydrochloric acid for one week. Table 2
Thus, it is clear that all of these alloys have super corrosion resistance.

[0028]

[Table 2]

Example 3 and Comparative Example 2 A commercially available 304 stainless steel similar to that used in Example 1 was used as a target substrate, and Nb pieces having a diameter of 20 mm and a thickness of 2 mm and a 99.9% purity were changed. When the Cr pieces added to the above, and the number is added (however,
In Comparative Example 2, neither Cr nor Nb pieces were used. )), An alloy was prepared in the same manner as in Example 1, and the composition and structure of the obtained alloy, and the results when immersed in 6 M hydrochloric acid at 30 ° C. for one week, are shown in Table 3. From Table 3, it is clear that these alloys have super corrosion resistance.

[0030]

[Table 3]

Example 4 Various commercial alloys containing Cr were used as a substrate, and various additional small metal pieces were placed on the substrate.
An alloy was prepared in the same manner as in Example 1 using a target to which r pieces were added, and the composition, structure, and
Tables 4 and 5 show the results of immersion in 6 M or 12 M hydrochloric acid at ℃ for one week. From Tables 4 and 5, it is clear that these alloys have super corrosion resistance.

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

As described in detail above, according to the present invention, a super-corrosion resistant alloy that can withstand a concentrated acid can be easily and inexpensively manufactured by using a commercially available alloy as a target base. be able to.

[Brief description of the drawings]

FIG. 1 (a) is a configuration diagram showing an embodiment of a sputter device used for producing a super-corrosion resistant alloy according to the present invention, and FIG. 1 (b) is a diagram of the sputter device of FIG. 1 (a). FIG. 4 is a perspective view illustrating details of a target holding unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Target assembly 2 Substrate 3 Vacuum container 4 Target base 5, 6 Additional element small piece 7 Copper backing plate 8, 9 Magnet 10 Target holder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C22C 27/02 102 C22C 27/02 102Z 103 103 27/04 27/04 101 101 27/06 27/06 38 / 00 301 38/00 301F 302 302Z 38/50 38/50 45/02 45/02 Z 45/04 45/04 Z 45/10 45/10 C23C 14/35 C23C 14/35 B (72) Inventor Kawashima Asahi 37-17 Hiyoridai, Taihaku-ku, Sendai City, Miyagi Prefecture (72) Inventor Li Koyo 2-3-48-222 Kashiwagi, Aoba-ku, Sendai City, Miyagi Prefecture F term (reference) 4K029 AA02 BA21 BA25 BB07 BB10 BC01 BD00 CA05 DC03 DC04 DC16 DC21 DC39 JA03

Claims (3)

[Claims] 1. One or more elements selected from the group consisting of Ta, Nb, Zr and Ti: 7 to 87 atomic%
And one or more elements selected from the group consisting of Cr, Mo and W: 5 to 87 atomic%, with the balance substantially 75 atomic% or less of Ni or Fe and N
A super-corrosion-resistant alloy consisting of an amorphous alloy or a nanocrystalline alloy produced by a sputtering method using a non-magnetic metal or alloy as a target substrate. 2. A method for producing the super-corrosion-resistant alloy according to claim 1 by magnetron sputtering, wherein the non-magnetic austenitic stainless steel, iron-based superalloy or Cr is used.
Is used as a target substrate, and Ta, Nb, Zr and Ti are added to a sputter erosion region of the target.
A method for producing a super-corrosion-resistant alloy, characterized in that one or two or more kinds selected from the group consisting of a required amount are mounted or embedded as targets. 3. A method for producing the super-corrosion-resistant alloy according to claim 1 by magnetron sputtering, wherein the non-magnetic austenitic stainless steel, iron-based superalloy or Ni is used.
An alloy is used as a target substrate, and one or two or more selected from the group consisting of Ta, Nb, Zr and Ti and one or two selected from the group consisting of Cr, Mo and W are formed in the sputter erosion region of the substrate. A method for producing a super-corrosion-resistant alloy, characterized in that a target in which a required amount of seeds or more is mounted or embedded is used as a target.