JPS6326346A - Tin coated work, and method and device for producing said work - Google Patents

Abstract

PURPOSE:To obtain the titled work which has the good adhesive power and quality of a film and permits production of tools, etc., having excellent characteristics by providing a composite layer consisting of a coating layer by an arc vapor deposition method and a coating layer by a melt vapor deposition method on the surface of a base material. CONSTITUTION:The work 2 consisting of a cutting tool, etc., is mounted and after a Ti raw material 16 is loaded into a hearth 4, the inside of a vacuum vessel 1 is evacuated to a vacuum. The work 2 is then heated 3 and soaked and after holding for the prescribed time, only the surface of the work 2 is allowed to cool down to a prescribed temp. An arc discharge is then generated in a Ti cathode 10 by a trigger 13 and a prescribed voltage is impressed or the work 2 by a DC bias power source 8 so that the work surface is sputter-cleaned by the Ti ions. The bias voltage is lowered after the sputter cleaning and gaseous N2 is introduced 6 into the vessel to execute the arc discharge of the cathode 10. The TiN layer is formed on the work as a 1st layer by such arc evaporation method. The TiN film (2nd layer) is thereafter formed on the work 2 by the operation similar to the above-mentioned operation, by which the TiN coated work is obtd.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to ion brating technology for coating surfaces with hard materials, and more specifically relates to ion brating technology for coating surfaces of workpieces such as tools and molds using arc evaporation. Composite structure of TiN by fused vapor deposition method
The present invention relates to ion blating technology for forming coatings.

(Prior technology) Chemical vapor deposition method (C
Products coated with titanium carbide (TiC), nitride (TiN), or carbonitride to a thickness of several microns using the physical vapor deposition method (PVD method) or physical vapor deposition method (PVD method) have excellent wear resistance and welding resistance, and are suitable for tools. Alternatively, it is known that superior performance can be obtained as a mold.

The conventional chemical vapor deposition method uses titanium tetrachloride (T j, CQ 4) as the source of the metal component titanium, and mainly uses N2, CH, CO1CO2, No.
etc., and further using IT2 as a carrier gas, 9
These raw material gases are dispersed and reacted in a high-temperature atmosphere of 00 to 1100°C to form titanium carbides, nitrides, and titanium on the surface of the base material.
This is a method of forming carbonitrides, etc., but when using metal materials such as high-speed steel and alloy tool steel as the base material, it is difficult to do so because the hardness decreases and thermal deformation is large in such high-temperature atmospheres. , it is not widely used in precision tools.

Therefore, the physical vapor deposition method (PVN method) and the plasma CVD method have been developed as techniques for causing a chemical reaction at a low temperature below the tempering temperature (approximately 550° C.) of these metal materials.

There are various methods for the former PVD method, for example, HC
D method (Hollow Cathode Dischar)
As shown in FIG. 5, in the fused vapor deposition method called geD deposition, a workpiece 2, a heater 3, and a hearth 4 are placed in a vacuum chamber 1, and a low voltage (
The Ti in the hearth is melted by an electron beam with a large current (300-60OA), and a reactive gas such as N2 or 02N2 is introduced from the introduction tube 6 to inject TiN or Ti onto the work surface.
This is a method to generate C (11 Kobe Steel Technical Report “Vol1
132, Ha 3, p. 80-84).

In the figure, 7 is an Ar gas introduction tube, and by applying a bias voltage to the workpiece 2 from a DC bias power supply 8, the workpiece 2 heated by the heater 3 can be bombarded with Ar ions.

Among these PVD methods, there is an arc evaporation type ion blating method that has recently started to be used. In this method, as shown in FIG. 6, a workpiece 2 is placed in a vacuum chamber 1, and a metal (cathode) 10 and the workpiece 2 are evaporated while introducing a reactive gas such as N2, C, H, etc. from an inlet 9. In this method, an arc discharge is generated by the arc DC power supply 11 during this period, and TiN or TiC is generated on the workpiece surface. In the figure, 12 is a bias DC power supply, 13 is a trigger, 14 is an infrared surface thermometer, and 15 is an exhaust port.

However, when these methods described above are applied to TiN coating, they all have advantages and disadvantages, and have the disadvantage that they cannot cope with the increasingly severe characteristics required for tools, molds, etc.

That is, in the HCD method, molten Ti is evaporated, so the TiN film formed on the work surface is very smooth and dense, but the adhesion is unstable due to Ar bombardment. On the other hand, in the arc evaporation method, the adhesion is good due to Ti bombardment, but it is due to arc evaporation.
Ti containing large cluster-like particles of ~5 μm
This method has the disadvantage that an N film is obtained and pinholes are likely to occur, and that the base material is softened and deformed. For this reason, a significant improvement in the service life of TiN-coated tools and the like formed by these methods cannot be expected.

The present invention was made in order to eliminate the drawbacks of the above-mentioned prior art, and the TiN film has good adhesion and film quality, making it possible to manufacture tools, molds, etc. with excellent properties. The purpose is to provide a new ion blating technology.

(Means for Solving the Problems) In order to achieve the above object, the present inventor first developed the conventional H
After examining various new methods that could take advantage of the advantages of the CD method and the arc evaporation method, we found that the good adhesion of the TiN film was achieved by the arc evaporation method, and then the HCD method was implemented to layer the TiN film with good quality. We came up with the idea of a brating method, and hereby we have made the present invention.

That is, the TiN-coated workpiece according to the present invention is characterized in that it has a composite layer on the surface of the base material consisting of a coating layer formed by arc evaporation and a coating layer formed by melt evaporation.

Further, the manufacturing method is characterized in that TiN is coated by arc evaporation and then TiN is coated by fused evaporation to form a composite layer on the surface of the base material.

Furthermore, a device for this purpose includes a work, a heater for heating the work, a hearth for melting Ti, and an electron beam gun for melting in the same device, a shutter between the work and the electron beam gun, and a Ti cathode and a 1-rigger. electrode and N
It is characterized by being equipped with two gas supply pipes.

The present invention will be explained in detail below based on examples.

(Example) FIG. 1 is a diagram showing an example of a continuous ion blating apparatus used for carrying out the method of the present invention.

In the same figure, a workpiece 2 to be coated is placed in a vacuum chamber 1, and a metal T to be evaporated is placed below the workpiece 2.
A hearth 4 for receiving raw material 16 is arranged. hearth 2
An HCD gun 5 for melting and vaporizing the Ti raw material is provided directly above the HCD gun 5, and an Ar gas introduction pipe 7 is connected to this. 6 is an introduction pipe for introducing reaction gas (or cooling gas) N2, 7 is a DC bias power supply for applying a bias voltage to the workpiece 2, 10 is a Ti cathode,
11 is an arc DC power supply, 12 is a spark supply power supply, 13 is a trigger, 15 is an exhaust port, 14 is an infrared surface thermometer, 18
is a thermocouple.

Further, within the vacuum chamber, a heater 3 is provided at a suitable location to heat the workpiece 2, and a movable shutter 17 is provided between the workpiece 2 and the HCD gun 5.

In addition, although the heater 3 is provided at one location in the upper right in the figure, it may be provided at other locations as appropriate, and the shutter 17 moves vertically in the vacuum chamber 1 two times even in the closed state.
It is arranged so that evaporated Ti does not substantially adhere to the workpiece 2, and may be dome-shaped.

An example of the procedure of a continuous ion plating process performed by the apparatus configured as described above is shown.

(1) First, a cutting tool such as a high-speed steel drill is attached as the work 2, and after charging the Ti raw material 16 into the hearth 4,
The inside of the vacuum chamber 1 is evacuated to below I x 10' Torr.

(2) Turn on heater 3 and heat work 2 to 400 to 500
℃ and hold for 30-60 minutes to soak the workpiece. It is important that this heating temperature is substantially lower than the tempering temperature of the workpiece (520 to 570°C, depending on the material, and 550°C in the case of high speed steel mentioned in -).

(3) After holding for a predetermined time, turn off the heater 3 and allow only the surface to cool naturally to about 350°C. Temperature control is performed using a surface thermometer 18.

(4) Next, the trigger 13 generates an arc discharge in the Ti cathode 10. At this time, the DC bias power supply 8
A voltage of -600 to -1° OOv is applied to the workpiece 2, and the surface of the workpiece is sputter-cleaned with Ti ions.

If the bias voltage is about −5° Ov, vapor deposition will occur, so the voltage is set to be higher than the above lower limit. After 30 seconds to 2 minutes, the arc DC power supply 11 is turned off.

The workpiece surface temperature and degree of vacuum in the above process are
The temperature changes as shown in Fig. 3 and Fig. 3. In particular, after the workpiece surface temperature has been cooled once, sputtering b' by Ti ions
Although the temperature is increased from
The degree of vacuum during bombardment increases to about 10"-5 Torr. In contrast, in the conventional HCD method, since Ar ion bombardment is used, the degree of vacuum increases to 0.05 to 0.1 Torr.
The bias voltage is -400 to -600V,
Spatter cleaning effect is small. Because of these differences, according to the present invention, it is possible to prevent the softening of the base material, and the formed Ti bombarded carbon dioxide is mixed with Ti at a depth of about 500 mm below the surface of the base material, according to Auger analysis. It is thought that the mixed Ti traps oxygen on the surface and subsurface of the base material, forming an extremely clean bombarded layer. Therefore, heating control using a heater has a significant effect on film formation.
Stronger and more stable adhesion can be obtained than conventional arc evaporation methods.

In addition, it is also possible to perform Ar bombardment in place of the Ti bombardment described in "-".

(5) After sputter cleaning, reduce the bias voltage to -50
Lower the voltage to ~300v and supply 0.01- of N2 gas through the inlet pipe 6.
0.04. Torr (see Figure 3). Then, the Ti cathode 1o is arc discharged.

By this arc evaporation method, a TiN layer is formed as a first layer with good adhesion. When the TiN layer has a thickness of about 1 to 2 μm, the arc DC power supply 11 is turned off. The reason why the bias voltage is lowered as above is because the hardness of the base material decreases as the temperature of the workpiece surface increases, and the reason why the ultimate vacuum level by introducing N2 gas is set to the above range is to prevent arc discharge. Between work 2 and Ti cathode 1o (usually
This is to confine the distance between 1° and 150mm.

This is because below 0.0.0 Torr, Ti ions show linear propagation and scatter, and on the other hand, below 0.04' Torr, they do not reach the work surface.

According to SEM observation, this TiN layer forms a layer in which cluster particles are mixed on the surface of the workpiece (see FIG. 8(a)).

(6) Next, turn on the heater 3 to maintain the surface temperature of the workpiece at 400 to 450°C (see Figure 2), and start the HCD gun 5 with the one that introduces Ar gas. Melt the Ti raw material and add N2 gas at 1-3 x 1
．． After applying a bias of -50 to -100 to the workpiece 2 and stabilizing the Ti melting spot, the shutter 17 is opened to release the Ti.
A N film (second layer) is formed on the workpiece. As a result, a very dense and smooth TiN layer of ultrafine particles (see FIG. 8(b)) is formed.

(7) After a predetermined time, turn off and cool the workpiece 2.

The thickness of the second layer TiN film is 0.3μ/n at a film formation rate.
It may be determined appropriately using +jn as a guide; for example, the thickness may be the same as that of the first layer. For cooling, N2 gas is introduced when the workpiece temperature reaches 300°C, and if necessary, a fan is used to perform gas cooling to about 150°C.

In the following steps (1) to (7), it is possible to omit some of the workpiece heating and cooling steps when the above arc evaporation method and I (CD method) are performed in batch mode, respectively, and the processing is greatly improved. Since the time is also shortened, there are advantages of energy saving and cost reduction.

Next, the characteristics of the TiN-coated product obtained by the above method will be described.

Figure 4 shows −1,1 obtained by various ion blating methods.
- Shows the cutting test results of a TiN-coated drill (outer diameter 6 mmφ). In the same figure, rHCDmJ is a case where a 2μ TiN film is formed only by the HCD method, and “arc evaporation method (no heater)” is a case where Ti bombardment is performed without using a heater and a 2μ film is formed by arc evaporation.
"Arc evaporation method (with heater)" uses a heater to control the workpiece temperature and performs Ti bombardment to form a 2μ thick film by arc evaporation, while the "method of the present invention" forms a 1μ thick TiN layer using arc evaporation method. Then H
Each figure shows the case where a 1 μm TiN layer is formed by the CD method. The cutting conditions are a cutting speed of 30 m/mj
n, feed rate 0, 1.8 mm/rev, 20 mm penetration, water-soluble cutting oil was used as the cutting oil, and 550C (He207-240) was used as the work material.

As is clear from the figure, the number of holes is significantly increased in the arc evaporation method in which the workpiece temperature is controlled by a heater, compared to the case in which arc evaporation is performed without temperature control by a heater. According to the invention method, it can be seen that the number of holes is significantly increased because the arc evaporation method and the HCD method, which involve controlling the workpiece temperature using a heater, are carried out consecutively.

In the above embodiment, a case was explained in which an apparatus in which the arc evaporation means and the HCD means were arranged vertically as shown in FIG. can.

The apparatus shown in FIG. 7 consists of a vacuum chamber 1 consisting of a plurality of processing chambers, a first chamber 21 for evacuation, a second chamber 22 for heating or Ar gas bombardment, and a Ti bombardment and arc evaporation chamber. It has a configuration in which a third chamber 23 for performing molten vapor deposition, a fourth chamber 24 for performing molten vapor deposition, and a fifth chamber 25 for cooling are successively connected to each other so as to be separable by a valve 26. Exhaust ports 15 are provided in each of the first to fifth chambers. A means that allows the workpiece to be moved, such as a guide rail or rail passing through each chamber, is installed in each chamber, and a workpiece-mounting carriage is run on the guide rail or rail.

The second chamber is provided with an Ar gas introduction pipe 7 and a DC bias power supply 8, and the third chamber is provided with a reaction gas introduction pipe 6 such as N2, an arc DC power supply 11, and a DC bias power supply 8. A cathode 10 is provided. The fourth chamber is provided with a reactant gas introduction pipe 6 such as N2 and a heater 3 inside, a hearth 4 and an electron beam gun 5 are provided in the lower recess, and a shutter 17 is arranged between the work stop position and the electron beam gun. , and further provided with a DC bias power supply 8. The fifth chamber is provided with a cooling N2 gas introduction pipe 27, a cooling fan 28, and a heat exchanger 29, respectively. Note that in order to energize the mobile cart, an energization method such as an auto connector one-way type may be adopted.

With such a horizontal continuous type device, the method of the present invention can be carried out continuously, making it possible to process a large amount in a particularly short period of time, and it is also possible to carry out multi-purpose processing such as carrying out each conventional processing method alone. It is.

Although - in each of the above embodiments, the arc evaporation process was carried out following the bombardment process, depending on the case, it is also possible to carry out only the bombardment process in advance in a batch manner using another device. Furthermore, in each example described in -1-, the second layer of TiN
Although layer formation was carried out by the HCD method, other coating methods such as the ARE method and the hot cathode method may be applied as a method for melting Ti instead of the HCD method.

(Effects of the Invention) As described in detail, according to the present invention, a composite layer of TiN is formed on the surface of the base material by arc evaporation method and evaporation deposition method, so that a TiN film with good film quality can be obtained. The film is used as a tool,
A hard coating that can be formed on the surface of a workpiece such as a mold, increases adhesion or prevents softening of the base material, and has excellent properties such as wear resistance and welding resistance. It becomes possible to manufacture a workpiece having the following characteristics. 1 more
It is also economical because different ion blating methods can be performed continuously in one device.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional view showing an example of a continuous ion brating device used to carry out the method of the present invention, Fig. 2 is a diagram showing the temperature transition of the workpiece surface in an example of the present invention, and Fig. 3 is a similar vacuum FIG. 4 is a diagram showing the cutting test results of the TiN-coated drill obtained by the embodiment of the present invention, and FIG. 5 is an explanatory cross-section showing the device for implementing the conventional I-I CD method. Figure 6 is an explanatory cross-sectional view showing an apparatus for implementing the conventional arc evaporation method, Figure 7 is an explanatory cross-sectional view showing another example of the ion brating apparatus used for implementing the method of the present invention, and Figure 8 is Electron micrographs (X2000) of the surface state of the TiN layer, (a) shows the surface state after arc evaporation, and (b) shows the state after HCD. 1...Vacuum chamber, 2...Work, 3...Heater, 4
... Hearth, 5... HCD gun, 6... Reaction gas (cooling gas) introduction pipe, 7... Ar gas introduction pipe, 8...
・DC bias power supply, 10...Ti cathode, 11...
・Arc DC power supply, 12...Spark supply power supply, 13...
・Trigger, 14... Infrared surface thermometer, 15...
Exhaust port, 16... Molten metal (Ti), 17... Shutter, 18... Thermocouple, 21... First chamber, 22...
・Second chamber, 23...Third chamber, =16- 24...Fourth chamber, 25...Fifth chamber, 26...Valve, 27...N2 gas introduction pipe for cooling, 28 ...Cooling fan, 29...Heat exchanger. Patent Applicant Kobe Steel Co., Ltd. Patent Attorney Takashi Nakamura Figure 1 Figure 2 Patent Application No. 1.69183 Prisoner 2 Name of the invention TiN-coated processed product and its manufacturing method and device 3 Relationship with the person making the amendment Patent applicant address 1-3-18 Wakihama-cho, Chuo-ku, Kobe, Hyogo Prefecture Name (119) Kobe Steel, Ltd. 4 Agent address: 5-35-5, Nishi-Nippori, Arakawa-ku, Tokyo 116-7 Electron micrograph of the surface state of the rTiN layer on page 17, line 10 of the amended statement of contents.” The description has been corrected to ``An electron micrograph showing the particle structure of the surface of the rTiN layer''.

Claims (4)

[Claims] (1) A TiN-coated workpiece whose surface is coated with TiN, which has a composite layer on the surface of the base material consisting of a coating layer formed by an arc evaporation method and a coating layer formed by a melt evaporation method. (2) A method for coating the surface of a base material with TiN, which is characterized in that TiN is coated by arc evaporation and then TiN is coated by fused evaporation to form a composite layer on the surface of the base material. manufacturing method. (3) The method according to claim 2, wherein the arc evaporation and the molten evaporation are performed in the same apparatus. (4) In an apparatus for coating the surface of a base material with TiN, a workpiece, a heater for heating the workpiece, a hearth for melting Ti, and an electron beam gun for melting are arranged in the same apparatus, and
An apparatus for producing a TiN-coated workpiece, characterized in that a shutter is provided between the workpiece and the electron beam gun, and further includes a Ti cathode, a trigger electrode, and an N_2 gas supply pipe.