JP2003342752A - Heat resistant and corrosion resistant member for vacuum use, vacuum apparatus having parts obtained by using the same member and coating method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat resistant and corrosion resistant coating member which is simultaneously provided with heat resistance, heat radiability and corrosion resistance, and is suitable for vacuum use, and to provide a coating method therefor. <P>SOLUTION: In the heat resistant and corrosion resistant coating member for vacuum use, the surface of a metallic base material is provided with plural coating layers, the outermost layer of the coating layers consists of a heat resistant and corrosion resistant material layer, and the intermediate layer in contact with the outermost layer consists of a mixing layer. The heat resistant and corrosion resistant material layer comprises amorphous carbon or nickel or nickel oxide. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant and corrosion-resistant coating member for vacuum, which has good resistance to corrosiveness of strongly oxidizing substances such as halogen and active oxygen, and at the same time has good heat radiation characteristics, and the coating. Regarding the method.

[0002]

2. Description of the Related Art CVD technology, vapor deposition technology, sputtering technology, ion plating technology, plasma application technology,
Physicochemical treatment technologies such as various etching techniques and various distillation separation techniques performed under vacuum or reduced pressure use strong oxidizing corrosive substances such as halogen-based gas and oxygen-based gas, or these substances are by-produced. Often a process. Therefore, the surface of equipment used under vacuum or reduced pressure in these processes, for example, the surfaces of wetted parts and gas contacted parts such as pipes, pump impellers, rotors, valves, process chambers, etc. due to these corrosive substances during the process, Further, it is exposed to a remarkably corrosive atmosphere by being promoted by the corrosion promoting effect by the moisture in the air when the process is interrupted or terminated and the atmosphere is released.

Therefore, it is necessary to manufacture these materials with a corrosion resistant material or to coat the surface with a corrosion resistant material. Since it is costly to make the entire equipment a corrosion resistant material, plating, coating,
A coating method such as vapor deposition has been used.

On the other hand, among these equipments, in equipments having a pump or other movable parts and having parts for generating frictional heat, or equipments having reaction heat or other heat sources requiring heat radiation, deterioration of the equipment due to heat is caused. In order to avoid it, it is also desirable to have a property capable of radiating heat well under vacuum or reduced pressure and keeping the temperature low. Therefore, the surface of these equipments is not only resistant to corrosion, but also has a high thermal emissivity (0.5 or more with an ideal black body being 1 or 0.7 to as much as possible).
It is also necessary to have 0.9).

FIG. 8 shows an example of a conventional nickel-based heat-resistant coating. A NiP coating or a Ni coating, which is a high-temperature corrosion resistant material, is applied on a base material 1, and a 3 "corrosion-resistant inorganic material is formed on the NiP coating or Ni coating. Materials such as SiO ₂ , Al ₂ O ₃ having a high thermal emissivity, or organic polymer materials have been deposited and applied.

However, Ni lacks heat radiation.
, Ni-P has low corrosion resistance, etc.
By the way, it was not always a satisfactory measure. in addition
SiO _TwoAnd Al_TwoO_ThreeThe layers are deposited by vapor deposition
However, it has a complicated shape, such as a turbo molecular pump blade.
In the parts of the above, even the smallest details can be formed uniformly without pinholes.
It was difficult. Especially Al_TwoO_ThreeIs weak to corrosive chemicals
In addition, the polymer film has a limited heat resistance,
Corrosive substances based on hydrogen halides such as hydrogen and hydrogen fluoride
Polymer film surface at the interface between the coating material (polymer) and the base material (metal)
At high temperatures, it diffused and permeated, causing corrosion and peeling.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional problems, and is a heat-resistant and corrosion-resistant coating member and coating suitable for vacuum use, which has heat resistance, thermal radiation and corrosion resistance at the same time. The purpose is to provide a method.

[0008]

A vacuum heat-resistant and corrosion-resistant coating member according to the present invention has a plurality of coating layers on a metal-based substrate, and the outermost layer of the coating layers is a heat-resistant and corrosion-resistant material layer. The intermediate layer in contact with is a vacuum heat-resistant and corrosion-resistant coating member made of a mixing layer, and the outermost heat-resistant and corrosion-resistant material layer is made of amorphous carbon, nickel or nickel oxide.

Since the present invention is intended to achieve the intended effect of the present invention by a plurality of coatings, the metallic base material is not particularly specified, but it has physical properties suitable for the material constituting the parts of the vacuum equipment. A metal or alloy can be selected. Then, the amorphous carbon, nickel or nickel oxide of the present invention was selected so that the outermost coating layer has both heat resistance and corrosion resistance. Then, due to the difference in the expansion coefficient between the outermost layer and the base metal, the mixing layer is formed for the purpose of relaxing the occurrence of thermal stress and the internal stress of the outermost layer coating itself, and avoiding the separation between the outermost layer and the base material surface. The feature is that it was introduced.

The mixing layer mentioned here is an intermediate layer which can be provided by driving the coating material near the surface layer of the base material, and has a gradient in the mixing ratio distribution of the base material and the coating material. Therefore, it has the effect of increasing the adhesion between the base material and the coating layer.

The amorphous carbon film is a dense film having a crystal structure in which a diamond crystal structure and a graphite crystal structure are mixed and containing carbon-hydrogen bonds. The film has a high resistance to corrosive substances and can withstand high temperatures. It has the property. The hardness can be adjusted by the hydrogen content, and the thermal emissivity can also be adjusted by adjusting the crystal structure and the hydrogen content.

The other outermost layer, nickel or nickel oxide layer, is a well-known material that does not require any special explanation, but is important as an outermost layer component that can simultaneously satisfy the heat and corrosion resistance, which is the object of the present invention. It is a good choice. But,
The heat radiation property is one of the elements of the constitution of the present invention, because a high degree of characteristics can be obtained by further taking the measures described later.

Further, the vacuum heat-resistant and corrosion-resistant coating member of the present invention further has a second intermediate layer between the mixing layer and the surface of the substrate, and the second intermediate layer is a semiconductor-based, ceramic-based or metal-based material. It is characterized by comprising a Ni or Ni-P film.

The semiconductor type means an intermediate substance such as TiO ₂ and Fe ₂ O _{3 which} has a heat and electric conductivity smaller than that of metal and larger than an insulator, and the ceramic type means Al.
_It refers to a substance such as ₂ O ₃ or SiO ₂ which is a derivative having a relatively small heat and electric conductivity.

Since the coating material and the base material are thermally insulated by the presence of the semiconductor-based or ceramic-based layer having a good heat radiation property by itself, the effect of diffusing heat into the base material is suppressed, and the present invention is realized. It is possible to improve the heat radiation characteristics of the member.

Furthermore, in the heat-resistant and corrosion-resistant coating member for vacuum of the present invention, the surface of the heat-resistant and corrosion-resistant coating member for vacuum has a rough surface having a height and period of unevenness in a substantially defined range at least on the surface of the coating surface. The height of the unevenness of the surface and the half of the period of the unevenness are 0.1 to 10
It is characterized in that it is in the range of 00 μm.

Since emissivity is zero for a perfect specular reflector, surface roughness affects emissivity. According to the Wien's displacement law, the light emitted by a black body (thermal radiation) has a wavelength λmax = 2897 / T μm which is inversely proportional to the absolute temperature of the black body.
Has a maximum intensity, and the distribution is expressed by Planck's distribution formula. Therefore, the wavelength included in the wavelength distribution corresponding to the temperature of the present invention and the size of the unevenness of the roughness of the heat radiation surface are included. By making sure that
Emissivity can be increased.

Furthermore, the present invention is also a vacuum apparatus characterized by having a component using the above-mentioned heat-resistant and corrosion-resistant coating member for vacuum.

As described above, in the semiconductor field such as an etching system utilizing a corrosive gas, the process is carried out while flowing the gas under a reduced pressure, so that the corrosion of the material of the apparatus used causes the corrosion of the product manufactured in the process. It has a great impact on quality. At the same time, shortening the life of the used equipment (parts, members) due to corrosion is reflected in the equipment cost and equipment operation rate,
It becomes a factor of product cost push. In particular, parts that are in contact with corrosive substances in vacuum equipment and that are exposed to high temperatures and subject to thermal mechanical stress are subject to deterioration, such as impellers and rotors for pumps, especially turbo molecular pumps. In addition, other movable parts that rotate and slide such as scrolls and valve parts require high corrosion resistance and heat dissipation.
Further, when used under severe conditions, it can be used for non-movable parts such as the inner wall of the duct and the inner wall of the container under vacuum to extend the life of the device.

In such a case, the present invention makes it possible to provide a vacuum device which is chemically and thermally protected and is extremely reliable and has a long life.

In the vacuum heat-resistant and corrosion-resistant coating method of the present invention, a plurality of coating layers are formed on a metallic base material, a heat-resistant and corrosion-resistant material layer is formed on the outermost layer of the coating layer, and an intermediate layer in contact with the outermost layer is formed. A heat resistant and corrosion resistant coating method for vacuum for forming a mixing layer, characterized in that the outermost heat resistant and corrosion resistant material layer is formed of amorphous carbon, nickel or nickel oxide.

Further, in the vacuum heat-resistant and corrosion-resistant coating method of the present invention, a second intermediate layer is further formed between the mixing layer and the surface of the base material, and the second intermediate layer is made of semiconductor, ceramic or metallic Ni. Alternatively, it is characterized in that a Ni-P film is applied.

Further, in the heat-resistant and corrosion-resistant coating method for vacuum of the present invention, the surface of the heat-resistant and corrosion-resistant coating member for vacuum is roughened at least on the surface of the coating surface with a cycle and amplitude in a substantially defined range, and the roughness of the roughened surface is high. And the half of the period of the unevenness is set in the range of 0.1 to 1000 μm.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, shapes, materials, relative positions, etc. of the products described in the present embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified, and are merely illustrative examples. Absent.

(Embodiment 1) FIG. 1 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 1 of the present invention.
The mixing layer 2 in which the base material component element and the outermost layer component element are mixed is formed on the metal-based material 1 by the ion implantation method or the plasma ion implantation method. The thin film 3 is amorphous carbon containing hydrogen bonds and is formed by the plasma ion implantation method described later. The hardness of the thin film 3 can be adjusted by the amount of hydrogen. Amorphous carbon that constitutes the thin film 3 is a film that has a crystal structure in which a diamond crystal structure and a graphite crystal structure are mixed and that contains carbon-hydrogen bonds. The thin film 3 is resistant to corrosion by a halogen-based substance, has a dense film, and has little erosion. The emissivity can be increased by adjusting the ratio of the graphite diamond structure and the amount of hydrogen.

(Embodiment 2) FIG. 2 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 2 of the present invention.
In this example, the surface of the substrate 1 is provided with irregularities of 0.1 to 1000 μm in advance, and the mixing layer 2 is provided on the irregular surface of Example 1.
Then, an amorphous carbon film is formed as a thin film 3 on the outer side of the film. The unevenness can be imparted to the surface of the base material by a usual method such as sandblasting, etching, vapor deposition, laser ablation, heat treatment, and oxidation. According to this example, it is possible to further increase the emissivity of the carbon film.

Amorphous carbon can be uniformly deposited on the surface of the base material 1 or the surface of the mixing layer 2 by a plasma ion implantation method in combination with plasma CVD and ion implantation even in a complicated shape. FIG. 7 shows a conceptual diagram of an apparatus for forming the amorphous carbon film of the present invention on a substrate. Substrate 1 installed in vacuum container 8
Then, a high frequency and a pulse voltage are applied by the high frequency power supply 11 and the pulse power supply 10 or 10 '. The gas g is introduced into the vacuum container 8 from the outside. Due to this voltage, plasma is generated around the substrate 1 and the target placed on the substrate 1, and at the same time, ions are applied by a negative pulse electric field. Pulse power supply is bipolar type 10 and negative pulse type 10 '
Either is acceptable. Further, the high frequency power supply 11 can be omitted.

(Embodiment 3) FIG. 3 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 3 of the present invention.
In this example, an example of a film in which unevenness is formed only on the surface of the amorphous carbon film (thin film 3) is shown. The unevenness has a height and a half-wavelength size in the range of approximately 0.1 to 1000 μm, and is formed by forming island-shaped bumps or forming depressions. The bump can be formed by depositing carbon by CVD of a hydrocarbon-based gas of 1 Pa or more. Further, the depression can be formed by shaving by etching with oxygen, hydrogen, a rare gas, or the like.

(Embodiment 4) FIG. 4 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 4 of the present invention.
In FIG. 4, in order to increase the emissivity of the amorphous carbon film of the thin film 3, ceramics Al ₂ O ₃ or SiO ₂ , or semiconductor TiO ₂ or Fe ₂ O ₃ , is previously formed as the second intermediate layer 5 on the substrate 1. Alternatively, a heat-resistant and corrosion-resistant metal Ni or Ni-p is formed in advance, and a carbon thin film 3 is formed therethrough for protection through the mixing layer 2.
This multilayer structure ensures high emissivity and at the same time high corrosion resistance. When the base material 1 is Al, Al ₂ O ₃ can be obtained by implanting oxygen ions into the surface of the base material 1 using the apparatus shown in FIG. Incidentally, nickel or nickel oxide may be formed by a sputtering method in vacuum other than the plating method. The amorphous carbon film can be uniformly formed by the plasma ion implantation method.

(Embodiment 5) FIG. 5 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 5 of the present invention.
In FIG. 5, the carbon thin film 3 in the multilayer film shown in FIG. 4 is doped with a plurality of other elements 6 and 7 (P, B, N, etc.) to increase the emissivity. In this case, the second intermediate layer 5 can be omitted.

(Embodiment 6) FIG. 6 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Embodiment 5 of the present invention.
FIG. 6 shows an example in which Ni or Ni oxide is used for the outermost thin film. That is, after forming the second intermediate layer 5 on the substrate 1,
A thin film 3'is formed together with the mixing layer 2. It is also possible to form unevenness by forming NiOx on the outermost layer and then reducing it with hydrogen or the like to obtain metallic nickel. Also in this case, the intermediate layer 5 can be omitted.

(Comparative Test) The effects of the members in each of the above-mentioned examples were compared by the following tests in comparison with the conventional members. For the corrosion test, a method of bringing the treated surface into contact with deliquescent aluminum chloride for a long time was used. Further, the heat radiation characteristic is obtained by comparing the temperature change after the electromagnetic wave is radiated for a certain time at room temperature with the characteristic of the black body under the same condition.
In the conventional method, in a corrosion test, 24 hours to 20 hours after the start of contact
In most cases, pinholes are generated within 0 hours, and the thermal radiation characteristics are also emissivity of 0.5 or less. In the method according to the present invention, the surface condition does not change in the corrosion test for 200 hours or more. The emissivity can be 0.5 to 0.9.

[0032]

As described above, according to the present invention, it is possible to provide a heat-resistant and corrosion-resistant coating member and a coating method having heat resistance, heat radiation and corrosion resistance, which are suitable for vacuum applications.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a heat resistant and corrosion resistant coating member for vacuum according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a heat resistant and corrosion resistant coating member for vacuum according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Example 3 of the present invention.

FIG. 4 is a cross-sectional view of a heat resistant and corrosion resistant coating member for vacuum according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view of a heat resistant and corrosion resistant coating member for vacuum according to a fifth embodiment of the present invention.

FIG. 6 is a cross-sectional view of a vacuum heat-resistant and corrosion-resistant coating member according to Example 6 of the present invention.

FIG. 7 is a conceptual diagram of an apparatus for forming a film of amorphous carbon of the present invention on a substrate.

FIG. 8 is a cross-sectional view of a heat-resistant and corrosion-resistant coating member for vacuum according to a conventional technique.

[Explanation of symbols]

1 substrate 2 mixing layers 3 thin film 3'thin film (Ni type) 5 Second middle layer 6 One of multiple elements 7 One of multiple elements 8 vacuum vessels 10 pulse power supply 1 10 'pulse power supply 2 11 High frequency power supply Half wave length of W unevenness H height of unevenness P vacuum pump g gas

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuji Asahara             4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Mitsubishi             Heavy Industry Co., Ltd. Hiroshima Laboratory (72) Inventor Toru Funada             4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Mitsubishi             Heavy Industry Co., Ltd. Hiroshima Laboratory (72) Inventor Takeshi Tanaka             Hiro, 2-1-1, Miyake, Saiki-ku, Hiroshima-shi, Hiroshima             Shima Institute of Technology (72) Inventor Toshinori Takagi             Hiro, 2-1-1, Miyake, Saiki-ku, Hiroshima-shi, Hiroshima             Shima Institute of Technology F term (reference) 4K029 DA01                 4K030 KA46 KA47                 4K044 AA01 BA06 BA12 BA18 BB03                       BB04 BB14 BC02 BC11 CA13                       CA14                 5F045 EC05 EM09

Claims (7)

[Claims] 1. A heat-resistant and corrosion-resistant coating member for vacuum having a plurality of coating layers on a metal-based substrate, the outermost layer of the coating layer being a heat-resistant and corrosion-resistant material layer, and an intermediate layer in contact with the outermost layer being a mixing layer. The heat-resistant and corrosion-resistant coating member for vacuum, wherein the outermost heat-resistant and corrosion-resistant material layer is made of amorphous carbon, nickel, or nickel oxide. 2. A second intermediate layer is further provided between the mixing layer and the surface of the base material, and the second intermediate layer comprises a semiconductor-based, ceramic-based or metallic Ni or Ni-P coating. The heat-resistant and corrosion-resistant coating member for vacuum according to claim 1, which is characterized in that. 3. The surface of the heat-resistant and corrosion-resistant coating member for vacuum forms a rough surface having a height and period of unevenness in a substantially specified range at least on the surface of the coating surface, and the height of the unevenness of the rough surface and the period of the unevenness are 1/2 size is 0.1
The heat-resistant and corrosion-resistant coating member for vacuum according to claim 1 or 2, wherein the thickness is in the range of 1000 µm. 4. A vacuum device comprising a component using the vacuum heat-resistant and corrosion-resistant coating member according to claim 1. Description: 5. A heat-resistant corrosion-resistant material for vacuum, wherein a plurality of coating layers are formed on a metal-based substrate, a heat-resistant corrosion-resistant material layer is formed on the outermost layer of the coating layer, and an intermediate layer in contact with the outermost layer forms a mixing layer. A coating method,
A heat-resistant and corrosion-resistant coating method for vacuum, characterized in that the outermost heat-resistant and corrosion-resistant material layer is formed of amorphous carbon, nickel or nickel oxide. 6. A second intermediate layer is further formed between the mixing layer and the surface of the base material, and a semiconductor system is formed on the second intermediate layer.
The heat-resistant and corrosion-resistant coating method for vacuum according to claim 5, wherein a ceramic-based or metallic Ni or Ni-P coating is applied. 7. The surface of the heat-resistant and corrosion-resistant coating member for vacuum is a rough surface having a height and a period of unevenness in a substantially specified range at least on the surface of the coating surface, and the height of the unevenness of the rough surface and the period of the unevenness are 1 The size of / 2 is 0.1-1
The heat-resistant and corrosion-resistant coating method for vacuum according to claim 5 or 6, characterized in that the thickness is in the range of 000 µm.