JPS6365081A - Surface coating method - Google Patents

Abstract

PURPOSE:To form a high hardness film on the surface of a base material by a simple means by pretreating the surface of the base material and forming a BN film on the pretreated surface by vapor deposition. CONSTITUTION:When a BN film is formed on the surface of a base material by vapor deposition, the surface is pretreated by polishing with cubic boron nitride (C-BN), coating with copper or formation of boron phosphonitride [B(PN)] by vapor deposition. Such method may be adopted in combination. Carbon tool steel, alloy tool steel, alumina or zirconia may be used as the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a surface wave and method for forming a highly hard coating on the surface of metal materials, ceramic materials, etc.

[Background of the invention]

Cubic boron nitride (C-BN) has a hardness second only to that of diamond, and has excellent properties such as high thermal conductivity, high insulation properties, and chemical stability, so it has recently been used in cutting tools and semiconductor materials. usage is increasing. The above characteristics of C-BN are compared to diamond, and C-BN is used for steel materials and N
i, It is highly useful for cutting tools because it does not suffer from baking due to chemical reactions with Co-based heat-resistant superalloys and is oxidized even at high temperatures.

In this case, if the surface of the base material of the tool can be coated with 0-BN as a thin film, the life of the tool can be significantly extended compared to the conventional method.

[Prior art and its problems]

Traditionally, hexagonal boron nitride (h-
A method of modifying BN') in a C-BNN production region at high temperature and high pressure is generally used. However, the above method does not yield 0-BN powder. So C-B
Vapor deposition methods, especially chemical vapor deposition methods (C
VD method) may be applied. When producing a BN thin film, the CVD method involves making a substance that serves as a B source and a substance that serves as an N source as gases, placing a base material heated to a reaction temperature in the gas, and allowing them to react in the gas phase. This is a method in which BN is vapor-deposited on the surface of a substrate, and a thin film with good adhesion and uniform thickness can be obtained, but the BN formed is usually h-BN with low hardness or amorphous BN. It is.

[Means for solving problems]

The present invention provides the following three methods as means for solving the above problems.

The first method is to polish the surface of the base material with C-BNP, and apply -BNl! The second method is to coat the surface of the base material with copper, and then deposit 1c on top of it.
The eighth method is a method of forming a BN film by vapor deposition.
In this method, a boron phosphorus nitride (B(PN)) film is first formed on the surface of the substrate by vapor deposition, and then BNM is formed on top of the film by vapor deposition.

In the third method of the present invention, more preferably B (P
N) Boron phosphide (BP) on the base material surface as a base for the film.
A film is formed, and then a B(PN) film is formed. Matasara R
- Preferably, the above three methods are combined, first coating the substrate surface with Cu, then polishing with C-BN,
On top of that, B(PN) and a BN pattern are formed by steaming 51#.

The base material used in the present invention is carbon tool steel.

Metals such as alloy tool steel, high speed tool steel, cemented carbide, alumina, zirconia, titania, silicon nitride.

This includes ceramics such as silicon carbide.

The present invention--herein, the above-mentioned BP film and B(PN) film.

Physical vapor deposition or chemical vapor deposition is applied to deposit the BN film. Gases used in chemical vapor deposition include:

B source: nczs, B2H6 B source: PCl3. P horse N source: N2. As a carrier for the above-mentioned gas, Ar IN2. As a reducing agent such as H, there is N2.

In the case of chemical vapor deposition, the substrate is placed in the above gas and 5 to 2
Under reduced pressure of about 0'IN)rr, plasma is generated and heated to 300 to 800°C to cause the above gas to react.

An example of the reaction mode of the above gas is shown below.

1. BCl3. When using PCjl, , NH3, N2 a, BCJ, +PCe3 8H2-BP+6HC
1b, BCI +PCl+(1-X)NU, +1H2
-B (P:tN t -z')+3 (1+x)
HCJiC, BOJ, +NI(8-BN+8FI(:A
'2, BOA'8. PCl, , N2. When using N2 a, BC? PCI, +3)r2-BP+6HCl
b, BOJ173+xPC/, +-4-(l-X)N
2-! 7(1+x)N2-B (Px Ntx)
+8 (1+x ”)HCIIo, BO13+ ”-
N2+4H2-BN+8H (J8, BCl3.PH,
, N2. When using L[2, a, fl(J'3+PH
8-BP+8HC1b, BOj? 3+XPH3++(
1-z) N2+8(1-x") N2→B(PxNl-E')+ 5Hcl C, BCl34-+N2+ 4-N2-BN+8HC1
4, B2H6, PHI3. When using N2 a, +B
2H6+PH8-BI'+aH2b, TB2H6+X
PH8+ 2 (I X)N2=B(PXN,-,)+
7(1±X')H.

0, +B2■6+ +N2→BN++H2 Above reaction 1
, 2, 8, 4) where a is a BP17) production reaction, b is a B(PN) production reaction, and C is a BN production reaction. 2nd method) Here, BN film deposition on the Cu surface and 1st method 1: BN film after C-BN polishing
For film deposition, C at 1°2.4 in the above reaction formula is used. In addition, in the eighth method, BP-I3 (1'N
> When forming a BN ball and a W film, each reaction formula 1, 2, 8, 41 (initially the gas composition shown on the left side of a, then the gas composition shown on the left side of b) , and finally the gas composition shown on the left side of ICC.

BP film formed in the above chemical vapor deposition, B(PN')
The thickness of the film, the BN film, is influenced by the reaction temperature and the molar ratio of the raw material gases. FIG. 1 shows the relationship between reaction temperature and film thickness in the case of chemical vapor deposition under reduced pressure. In this case 1
-C reaction was carried out for 20 minutes. As shown in FIG. 1, as the reaction temperature increases, the film thickness increases at an accelerated rate. Also N2/B
Figure 2 shows the relationship between o13 and film thickness? This is shown. In this case 2
-C reaction was carried out for 20 minutes. Looking at Figure 2, N2/B
The largest film thickness is observed when CIg is in the range of 10 to 20.

The membrane in the third method of the present invention is not necessarily BP-B (
I'N)-BN, but not limited to the 3N film of U
A two-layer film of (PN)-BN may be formed, and in addition to chemical vapor deposition, physical vapor deposition is applicable, in which a BP source, a B(PN) source, and a BN source are heated in a vacuum and vapor deposited on the substrate surface. may be done.

[For production]

Polishing the base material surface with 0-BN means polishing the base material surface with 0-BN.
It is effective in increasing the number of BN crystal nuclei and promoting the formation of a C-BN film.Cu has a lattice constant that almost matches that of C-BN and has a cubic crystal structure, so BN can be deposited directly on Cu. If allowed to do so, the BN film will have the same crystal structure as the underlying layer, that is, a cubic structure, due to the induced precipitation effect.

Further, the BP and B(PN) films deposited on the substrate surface also have a cubic crystal structure, and when a CBN film is formed on the B(PN') film by vapor deposition, the structure becomes a cubic crystal structure due to the induced precipitation effect. B.P.
Since B (PN) is a ceramic of the ■-V group compound like BN, the above-mentioned induced precipitation is easy and the adhesion between the films is good.

〔Effect of the invention〕

In the present invention, the force applied to the base material surface can be easily applied by simple means.
This makes it possible to form a highly hard coating.

Example 1. (Apparatus) FIG. 8 shows an apparatus system used in the present invention. In the figure, (1) is a gas passageway communicating with the N2 or NH8 source, (2) is a gas passageway communicating with a BCl3 or B2H6 source, (3) is a gas passageway communicating with an H2 source, and ( 4) is a gas passage that connects to the PH1 source; (5) is a gas passage that connects to the Ar source; gas passages (1), (2>, (8), and (4)) are provided with Pressure gauge (1)A, (2)A, (a)A,
(41A and flowmeter (1)B, (2)B, (8
)B, (41B are provided, and the gas passage (5
) is provided with a pressure gauge (5)A. The gas passage (5) has a gas passage (6) having a flow meter [6) A, a flow meter (7) A, and a PCl3 saturator (7) at the rear end.
)B, a pressure gauge (7)C and a gas passageway (7) having a pulp (7)D are arranged in parallel.

The gas transmission passages (1), (2), (8), (
4), (6), and (7) are merged at the rear end by a merging path (8) that branches from the gas feed passage (1) via a three-way valve (1)C, and the merging path (8) A reaction path system having an inductively coupled reaction tube (9)A is provided from the reaction path C9), and a pressure gauge 04A and a liquid N
A suction path GO having two traps αOB and a vacuum pump QOC is arranged. In addition, the latter part of the feed passage (1) is connected to the reaction tube (9) Ac N via the three-way pulp (1) C.
A conveyance path (1) is provided which is used only when conveying H.

FIG. 4 shows details of the inductively coupled reaction tube [9]. 0])A in the figure is a tube, with a thermocouple inside)A
is inserted, and the corresponding V! A heating medium HA made of graphite 1 is inserted at the tip of the couple HA, a coil A is placed on the outside, and the base material W to be processed is connected to the heating medium inside the tube 811◇. ) is set on A.

Example 2. , (First method) In the apparatus shown in Example 1, the inside of the reaction tube (9) A was vacuum bonded (QOC) to 5 to 20 T via the suction path αO.
Set the pressure to orr, and set the frequency to coil A to 1.1.
Plasma is generated by applying a high frequency wave of 1.56 MH2 and an output of 100 to 600 W, heating the exothermic medium A and setting the temperature inside the reaction tube (9) A at 800 to 800°C.

The temperature inside the reaction tube (9) A is detected as the temperature of the heating medium 41A by the thermocouple A, and as a result, the temperature inside the reaction tube (9) A is detected as the temperature of the heating medium 41A.
C) Adjust the output of high frequency applied to A to react to the reaction tube (9) A.
Keep the internal temperature constant.

In this example, the surface of the base material is polished with C-BN, and various gases are passed through the reaction tube (9) under the following conditions to form a BN film.

BC,l, :N2:N2:Ar=1:10:
8:6 (volume ratio) flow rate = 0.4 ax/see Reaction time = 20 minutes Reaction temperature 520°C Reaction pressure 5 TOrr High frequency output = 500W Example 8. (Second method) Substrate surface topography Cu is coated by electrolytic plating under the following conditions, and a BN film is formed thereon using the same conditions as in Example 2.

Electrolytic plating condition bath composition CCuS04-5N20=100/lH2So
4=100g/l Temperature 80°C Current density 4 A/dm2 Example 4. (Eighth Method) In this example, the reaction 2 described above is applied. PCj28 is connected to the PCI 8 saturator (7) B kept at 0°C in the gas passageway (7). Ir is delivered as a carrier from a CAr source in 8 solution. Then, various gases are passed through the reaction tube (9)A through the following steps, and the base material surface)n B P
-B (PN)-BN film is formed.

a, BCI, :PCI3:N2:Ar=2: 1:8:
6 (volume ratio) b, further adding N to the above gas mixture PO2”N
Add so that z=1:20.

c. Stop the supply of PCA'6 and change BCl3:N2:N
2:Adjust Ar=1:10:8:6.

Reaction time = 20 minutes Flow rate = 9.4 (11/9eC Reaction temperature = 5
20° C. Reaction pressure = 5'porr High frequency power = 500 W In this way, a coating similar to that shown in FIG. 5 is formed on the base material W.

In the BNgll obtained as described above, a C-BN structure was recognized by Xfi1m analysis, and a micro-Vickers hardness of 4000/1nI2 or more was obtained.

[Brief explanation of drawings]

Figure 1 is a graph with reaction temperature (°C) on the horizontal axis and film thickness (μm) on the vertical axis, and Figure 2 shows N2/BC1 on the horizontal axis.
3 (molar ratio) and the film thickness (μm) is plotted on the vertical axis. Figure 3 is a schematic diagram of an embodiment of the apparatus system used in the present invention, and Figure 4 is a diagram of a reaction tube of the rust-conducting type reaction tube. The detailed illustration, FIG. 5, is a schematic side sectional view of the coated substrate. In the figure, W...Base material, F...BP film, F2...
...B (PN) membrane, F3...BN membrane patent applicant Daido Steel Co., Ltd. Figure 1: 1 degree (°C) ~'BCfLs

Claims (5)

[Claims] (1) A surface coating method characterized by subjecting the surface of a substrate to a preliminary treatment and forming a boron nitride film on the treated surface by vapor deposition. (2) The surface coating method according to claim (1), wherein the pretreatment is polishing the surface of the substrate with cubic boron nitride. (3) The surface coating method according to claim (1), wherein the pretreatment is a process of coating the surface of the substrate with copper. (4) Claim No. (1) in which the preliminary treatment is a treatment of forming a phosphorus boron nitride film on the surface of the substrate by vapor deposition.
The surface coating method described in Section 1. (5) The pretreatment is a process that performs two or three processes: polishing with cubic boron nitride, coating with copper, and forming a phosphorus boron nitride film by vapor deposition. The surface coating method described in item (1).