JPS5822375A - Superhard coating metal material and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain the titled material having high adherent property and not generating crack or peeling, in depositing a carbide coating on the surface of a base material based on C containing iron by chemical vapor deposition, by preliminarily forming an intermediate layer preventing the decarburization of the base material. CONSTITUTION:For example, when the titled material is used in a fixing ring of a mechanical seal, an intermediate layer 11 comprising Ni or Co is formed on a base material 10 made of cast iron processed into a predetermined shape by electrolytic plating. In the next process, to the surface of the intermediate layer 11 on the base material 10, a superhard coating 12 comprising carbide such as titanium carbide is formed by a chemical vapor deposition method. In this case, the base material 10 is not decarburized because the layer 11 is present and the formation of a decarburized layer is prevented. Therefore, the coating 12 is formed on the base material 10 densely and uniformly as well as adherent force thereof can be made high and crack or peeling of the coating can be prevented in a cooling process after the coating 12 is formed. In addition, the intermediate layer 12 can be formed from titanium nitride according to chemical vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal material having an ultra-hard coating formed on its surface and a method for manufacturing the same.

For sliding materials such as mechanical seals, cutting tools, etc., rounded, ultra-hard metal, shellac materials, etc., which require strong wear resistance, are widely used. However, from Kei's point of view, it is the mechanical properties of the material that are involved in wear resistance, so even if you do not add up the wear resistance of the entire material,
This function can be fulfilled by strengthening only the surface to make it more wear resistant.

For this reason, nine sliding parts #, etc., have been developed in which an ultra-hard coating is formed on the surface of a relatively soft material.

Conventionally, a chemical vapor deposition method (hereinafter referred to as CVD method) has been developed as one of the methods for forming an INK carbide coating on surfaces such as cast and iron. This CVD method uses titanium carbide (TIC) on the surface of a base material such as cast iron.

A coating with excellent wear resistance such as silicon carbide (Sic),
This is a means of coating by a chemical reaction shown in the following formula (1) or (2).

+11 'rtcz4 + 2H2→Ti + 4H
C1T50CH4→TiC+ 2Hz (21CHs81CLj+ Hz→S Fish C+ 3HCt
+H The CVD method described above has the advantage of being able to densely and uniformly coat even complex-shaped substrates with a highly pure carbide hard film, and its practical use is progressing.

However, in such a CVD method, when an iron-based material or an iron alloy material containing carbon is used as a base material and a carbide film typified by silicon carbide in titanium carbide is to be coated on the surface Ki[* of the base material] However, there is a problem in that a part of the carbon component on the surface of the base material is vertically removed during the chemical vapor deposition process, resulting in a decarburized layer. The occurrence of such a decarburized layer impedes the desired dense and uniform coating of the carbide film, weakens the adhesion of the film to the base material, and causes drawbacks such as a decrease in strength and toughness. Due to the difference in thermal expansion coefficient between the coating material and the coating material, cracks were generated on the surface of the coating during the cooling process after the coating was formed], and a portion of the coating was peeled off from the base material, causing weight.

The present invention was developed based on the above circumstances, and its purpose is to prevent decarburization of the base material, coat the base material with a carbide film densely and uniformly, and improve adhesiveness. This is part of an attempt to provide a carbide-coated metal material that does not cause cracks or peeling, and a method for manufacturing the same.

That is, one aspect of the present invention is a carbide coated metal material characterized by forming an intermediate layer between a base material and a carbide coat made of carbide to prevent decarburization of the base material. Release vi4
E) 01 uses titanium nitride as the intermediate layer,
The titanium nitride intermediate layer is formed by chemical vapor deposition, and
This is a method for producing a carbide coated metal material, characterized in that a carbide carbide coat is formed on the surface of an O intermediate layer by chemical vapor deposition.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 114.

Figure 1 shows an example in which the carbide-coated metal material according to the present invention is used in a fixed ring of a mechanical seal, where l is a casing, and 2 is a casing.
is a rotating shaft that passes through the opening J of the casing 1. Inside the casing 1, the above opening aK faces and is fixed @4
is arranged, and this fixing 1i4 maintains a seal with the inner surface of the casing 1 via an O-ring 5. A rotating iig is closely connected to the fixed ring 4. This rotating IC is made of a soft material such as a molded car, for example, and the zero rotating ring σ, which is trapped so as to be slid and rotated by the fixed i14 and its contact surface, is connected to the rotating shaft 2 through the hole /-1. Rotates as one,・
The fixed ring 6FC is pressed by the spring aK. Note that the rotation iag is between K and the rotation axis 2.
Sealing performance is maintained through O-ring I.

Therefore, as the rotating shaft rotates 20 times, the rotation *g is rotated integrally, and the rotation mg of H and the meeting surface of the fixed ring 4 are relatively slid and rotated, but these meeting surfaces are in close contact with each other. This prevents liquid or gas leakage.

For the fixing H14, the cemented carbide coated metal material of the present invention is used, and an intermediate layer 11 is formed on the surface of a base material 10 made of, for example, cast iron.
A cemented carbide coating 12 is formed on the surface of 1. middle layer 11
is formed by plating nickel or cobalt, and the layer thickness is approximately 5 to 50 μm. Further, the carbide coating 11 is formed of titanium carbide or #i silicon oxide by the CVD method, and its film thickness is limited, but is preferably about 10 to 50 #.

A method of manufacturing a cemented carbide coated metal material by fixing 3j4 and changing the shape will be described.

Figure 2 shows a schematic configuration of a CVN device in which a nickel or cobalt plating layer is formed as the intermediate layer 11 and silicon carbide is coated as the carbide coating 12. 2# is a hydrogen I pump], which has a flow control valve Jja and a flow meter Jja in the middle of the piping 21 to connect the vaporizer 24.
It is connected to the. The hydrogen pump Xa of the octopus is connected to another pipe 25], and a flow control valve xxb and a flow meter xsb are provided in the middle of this pipe 25. The vaporizer 24 has a temperature control device fzg with heating means. The vaporizer 24 contains methyltricholsilane (CH381C
j3) is stored. A pipe 21 led out from the vaporizer 24 is joined to a pipe 25 into which the hydrogen is led directly from the pump 20. The valve 28 is made of an inert fX-temperature such as helium, and is provided with a flow control valve 22 and a flow needle 23 in the middle of the pipe 2#. This pipe 2# is connected to the confluence pipe 10 together with each of the above-mentioned pipes 15 and 2r. The confluence pipe 7o is the reactor JJ
The O-reactor J1 that has been introduced has a cylindrical reaction vessel S2 with excellent heat resistance and is made of porcelain or the like with both ends sealed, and a temperature change control device J1 with a heating means (with The reactor J1 is equipped with a trap device xsy for absorbing gas generated by a chemical reaction via a pipe J4.
c is connected. The trap device 111flC is connected to an external discharge pipe 3ε.

A method for producing a superhard coated metal material using a CVD apparatus having such a configuration will be described.

First, a base material 10 made of cast iron or the like is processed into a predetermined shape.
Intermediate layer 11 consisting of , , =-methyl or :IA ruto
form. In this case, the nickel or copper layer is formed by a known electrolytic plating method, and the layer thickness may be approximately 9, for example, 15 tones.

The base material 10 on which such an intermediate layer 11 has been formed in advance by plating is housed in the container J2 of the reaction device 11. First, inert gas is poured into reactor J1 from pump 28! An inert gas such as helium is supplied to the inert gas W, l! i Heating the base material 1- in air at a predetermined temperature (for example, 1200° C. 1 degree) t. As a result, impurities and impurity gas on the surface of the layer are released, and the intermediate layer 11
Clean the surface.

On the other hand, the methyl trisilane in the vaporizer 24 is heated to a predetermined temperature (for example, 20 to 3(1) K), and the vapor pressure of the methyl trisilane is raised to a constant value (for example, 180--).
To this, hydrogen is supplied from the hydrogen pump 20 at a constant flow rate (for example, 0.847 ml/m).

Such a vaporizer 24 is connected to the vessel 5xPc pipe 2r of the reactor J1, which has completed the purification process, and at the same time, the pipes xtsp and 29 are also connected, so that the vapor of methyltrichlorosilane - hydrogen and inert gas can be stored. l5JjK
supply In this way, by allowing the chemical reaction of formula (2) described above to occur in the container 32 for about one hour), the superhard coating 12 of silicon carbide can be formed on the surface of the intermediate layer 11.

After the coating 12 is formed, the pipes xr and zs are closed, and only the inert +jkf gas is supplied into the container S2, and the reactor J1 is slowly cooled in an active gas atmosphere for several years. After cooling, the product is
Take out the ILn and polish the sliding surface of the @ZX as necessary to make it function as the national standard 1 of the mechanical seal. By this polishing), for example, the surface roughness is 0.05, Ra e II ridges are 0.3, 1
Finish 1mK.

When the cross-sectional structure of the carbide-coated metal material produced as described above was subjected to line analysis using an X-ray microphone quadrimeter, a schematic diagram as shown in FIG. 3 O was obtained. That is, cast iron (r
A nickel-plated intermediate layer 11 having a thickness of about 15 μm is formed on the surface of a base material 10 consisting of . It was recognized that there was. In this case, no decarburized layer was observed on the surface of the base material 10.

When forming the carbide coating 12 by chemical vapor deposition, such a carbide coating metal material is not decarburized because the surface of the base material 10 is covered with the intermediate layer 11 in advance.
] Generation of a de-envy layer is prevented. Therefore, the coating 1[12 is formed densely and uniformly on the base material 10, and
The bonding force to the base material 101IC also increases. In addition, during the cooling process of the coating xl (D formation 11), the coating 1
2. No peeling occurred during cracks.

In addition, when such a carbide-coated metal material is used as the fixed ring 4 in the mechanical seal shown in Fig. 18g1, it has good adhesion with the rotating ring 5 and effectively prevents oil and gas leaks. Moreover, the coating 12 has a small coefficient of friction and is extremely excellent in wear resistance. This improves durability.

Fig. 4 shows the results of an experiment regarding the wear characteristics of the fixed ring 4 of the present invention according to the above embodiment and another fixed ring manufactured from a conventionally known material. That is, the samples used were cast iron without surface treatment, T-Met, Arunna, a silicon carbide sintered body as a whole, and a 0-turn Ill with a silicon carbide carbide coating according to the present invention. A molding carn J10 was used as the molding carn, and the number of revolutions was 2.
00Or', p, wa, surface pressure of 10 kP/cnhc, and the amount of wear on the sliding surface after 10 hours of rotation and sliding vk#c was measured. As can be seen from FIG. 4, it can be seen that the cemented carbide coated metal material of the present invention has excellent wear resistance and improved durability characteristics.

In the above embodiment, an example in which a nickel or =PAL) O plating layer was used as the intermediate layer 11 was described in detail, but titanium nitride may also be used as the intermediate layer 11, and a manufacturing method for the case where titanium nitride is used. will be explained based on FIG.

Fig. 5 shows a device in which a means for forming titanium nitride on the surface of the base material by cvn#& has been added to the apparatus shown in Fig. 2.
4), and has a temperature control device 51 with heating means. The vaporizer 5”□O has a pipe 52 having a flow control valve 2241 and a flow meter JJd in the middle.
Hydrogen is connected to the pump 20 through the pipe 53, and is connected to the confluence pipe xoK@@ via another pipe 53.

Further, 54 is a nitrogen inlet, which is connected to the confluence pipe 111 via the pipe 15. This piping 55 is also provided with a flow control valve 22 and a flow meter 2S.

A procedure for manufacturing a cemented carbide coated metal material using such an apparatus will be explained.

The base material 10 processed into a predetermined shape is placed in a reactor 110 volume BaX.
to be contained within. Then, an inert gas is supplied from the inert gas pump 28 into the container S2 of the reaction apparatus, and the base material 10 is heated in this inert gas atmosphere H to perform a degassing treatment.

On the other hand, hydrogen is introduced from the hydrogen tank 20 into the vaporizer 50 containing titanium tetrachloride to vaporize the titanium tetrachloride. Titanium tetrachloride vapor from the vaporizer 10, hydrogen from the hydrogen tank 20, and nitrogen from the ii1 element tank 54 are supplied into the reactor vessel 12. In this case, titanium tetrachloride and nitrogen are supplied. Select the ratio appropriately (for example, N2/T
I CL4 = 6 to 10) l, and base material 10 to 100
Heating to a temperature of 0°C m & water volume and supply are also suitable #! AlIC
Control.

As a result, (3) 2〒ICL4+'N2+4M yi → 2T breath N+8H
A chemical reaction of CA occurs, and titanium nitride (TiN) becomes the base material 1.
Formed on the surface of 0.

Subsequently, the f-sulfur supply to the reactor J1 is switched and the temperature is controlled to form a silicon carbide film on the surface of the titanium nitride by the chemical vapor deposition method of depositing silicon carbide as shown in FIG.

The cemented carbide coated metal material manufactured in this way has a titanium nitride coating as the intermediate layer II, but this material is different from the one using nickel plating or part plating as the intermediate layer 11, and the one using nickel plating or part plating as the intermediate layer 11. There is no difference in properties, and it has excellent wear resistance.

According to the above manufacturing method, by simply adding a device for forming an intermediate layer of titanium nitride to the chemical vapor deposition device for forming the film shown in Fig. 3, the intermediate layer and the film can be continuously formed. Since the manufacturing equipment is simple, there is no need to transfer the base material 1# on which the intermediate layer is formed from the reaction chamber Tll, and therefore the manufacturing labor can be significantly reduced. . In particular, when the reactor 31 is transferred, impurities and impurity gas adhere to the surface of the intermediate layer 11, which requires purification such as degassing again before forming the coating 12. If the coating film 12 is subsequently formed in the same reaction device 31 after the formation of the coating film 11, there is an advantage that such troublesome effort is not required.

Note that the first aspect of the present invention is not limited to each embodiment. That is, as for the intermediate layer 11, nickel plating, cobalt plating, and titanium nitride are exemplified in the embodiments, but in short, this intermediate layer 11 is used to decarburize the base material 10 when the carbide coating 12 is chemically vapor deposited. Therefore, as the intermediate layer 11, any material can be used as long as it has heat resistance higher than the reaction temperature in chemical vapor deposition (SC) and covers the surface of the base material to prevent decarburization. Bye. and the intermediate layer 1 in terms of mechanical properties.
1 has a bonding force to both the base material 10 and the coating 120, has a certain degree of toughness, and has a coefficient of thermal expansion between the tensile coefficient of the base material 10 and the coating 1205. Therefore, as the intermediate layer 11, materials such as nickel, cobalt, and titanium nitride, such as niobium nitride (NbN), can also be used.

Further, the carbide coating 12 is not limited to titanium carbide or silicon carbide, but may also be made of boron carbide (11
It is also possible to use carbides containing 4C) and the like.

Furthermore, the chemical vapor deposition method of silicon KNide does not require the adoption of the above-mentioned equation (2); for example, 81Cj+CHn+
Hz→81 C+ 4 HCj + 11! It is also possible to use a reaction formula such as

Furthermore, regarding the reactor JJK shown in FIG. 2 and FIG.
The container can be constructed of J24 Persian type.

As described in detail above, the first aspect of the present invention is to provide an intermediate layer having heat resistance and preventing decarburization of the wrinkled base material on the surface of a base material mainly made of iron containing carbon and made of a round material. A superhard carbide coating is formed on the surface of this intermediate layer by chemical vapor deposition. Therefore, since the intermediate layer prevents decarburization of the base material, the adhesion of the carbide coating is improved and a uniform coating is formed in several places. Moreover, the carbide coating has little peeling during cracks, maintains wear resistance, and has excellent durability and is round. Since a steel alloy is used as the base material, the shape of the base material can be processed arbitrarily, making it easy to obtain products with complex shapes, and the base material provides most of the mechanical strength. Since it bears a heavy burden, it can withstand shocks and the like.

The second invention is a method of forming an intermediate layer on the surface of a base material by chemical vapor deposition, and then forming a carbide coating on the surface of this intermediate layer by chemical vapor deposition.
The production of the cemented carbide coated metal material according to the invention can be carried out continuously using the same reaction apparatus, which has the advantage of greatly simplifying the labor and eliminating four steps.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, Figure 1 is a configuration diagram of a mechanical seal, and Figure #I2 is a schematic diagram of an apparatus used in the method for manufacturing a cemented carbide coated metal material used as a fixed ring. FIG. 3 is an X-ray analysis diagram of a product manufactured using the above apparatus, and FIG. 4 is a characteristic diagram showing the wear resistance of the above product and a conventional product. Further, the WXs diagram is a schematic configuration diagram showing an apparatus for use in a manufacturing method according to another embodiment. DESCRIPTION OF SYMBOLS 10... Base material, 11... Intermediate layer, 12... Carbide coating. Applicant's agent Patent attorney Takeshi Suzue Hikoyoko 3 Figure 1! IP4 illustration 5 illustration

Claims (1)

[Scope of Claims] Cυ An intermediate layer having heat resistance and preventing decarburization of the base material is formed on 0!1 side of a base material made of a large material mainly composed of iron containing carbon, and this intermediate layer is A cemented carbide coated metallic material characterized in that a carbide coating made of chemically vapor-deposited carbide is formed on the surface of the layer.(2) A patent claim characterized in that the above 1iiWl coating Ili is expanded titanium or silicon carbide. Paragraph (1) of aS Building 0 Carbide metal material $i! . (31) The cemented carbide coated metal material according to Clause (1) or (2) of Subsection S of the patent claim, characterized in that the intermediate layer is a nickel or co/gold plated layer. (4) The above-mentioned The cemented carbide coated metal material according to claim 1 or 2, wherein the intermediate layer is made of titanium nitride. (5) Made of a material mainly composed of iron containing carbon. The surface of the base material (111tI, characterized in that an intermediate layer made of titanium nitride is formed by a chemical vapor deposition method, and a carbide coating made of carbide is formed by a chemical vapor deposition method on the surface of the intermediate layer)
Method for producing coated metal material.