JP2797612B2 - Artificial diamond coated hard sintering tool member with high adhesion strength - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an artificial diamond-coated hard sintered tool member having an extremely high adhesion strength of an artificial diamond coating layer to a substrate surface.

[Conventional technology]

In general, as a typical method of depositing and forming an artificial diamond coating layer on the surface of a substrate made of various materials, for example, (1) a method using a thermionic emitting material described in JP-A-58-91100, 2) A method using plasma discharge by high frequency described in JP-A-58-13511, (3) A method using plasma discharge by a micro-group described in JP-A-58-110494, and the like. Are known.

In the above method (1), as shown in a schematic cross-sectional view in FIG. 1, hydrocarbon and hydrogen introduced through a reaction mixture gas introduction pipe 2 opened at an upper position in a vertical reaction vessel 1 made of quartz are removed. A reaction mixture gas as a main component is placed at a position below the reaction mixture gas, for example, a metal tungsten filament 3 as a thermionic emission material, and a substrate 5 supported on a base plate 4.
, And during this time, the atmospheric pressure in the reaction
Hold at 30 Torr and filament 3 1500-2500
By heating the reaction mixture gas and activating the substrate disposed below at a predetermined interval, setting the substrate surface temperature to 600 to 1000 ° C., and performing a reaction for a predetermined time in this state. This is a method of depositing and forming an artificial diamond coating layer on the surface of the substrate 5.

Further, in the above method (2), as shown in a schematic sectional view in FIG. 2, a substrate 5 is placed in a central portion of a quartz horizontal reaction vessel 1 and a reaction provided on one side of the reaction vessel 1. A reaction mixture gas containing hydrocarbons and hydrogen as main components is introduced from the mixture gas introduction pipe 2 and exhausted from the other side of the reaction vessel 1 while maintaining the atmospheric pressure in the reaction vessel 1 at 3 to 25 Torr. At the same time, conditions such as a frequency of 13.56 MHz and an output of 500 W are added to the high-frequency coil 6 provided on the outer periphery of the central portion of the reaction vessel 1 to induce plasma discharge around the substrate 5 in the reaction vessel 1. A method of forming an artificial diamond coating layer on the surface of a substrate by causing the reaction mixture gas to be heated and activated by discharge and raising the surface temperature of the substrate, and allowing the reaction to proceed for a predetermined time at a substrate surface temperature of 600 to 1000 ° C. It is.

Further, in the above-mentioned method (3), as shown in a schematic sectional view in FIG. 3, a substrate 5 is placed at a central position in a vertical reaction vessel 1 made of quartz and provided on the upper part of the reaction vessel 1. A reaction mixture gas containing hydrocarbons and hydrogen as main components is introduced from the reaction mixture gas introduction pipe 2, and exhausted from the lower part of the reaction vessel 1 while maintaining the atmospheric pressure in the reaction vessel at 15 to 50 Torr. A waveguide 7 provided on the outer periphery of the central portion of the reaction vessel 1
The microwave supplied, for example, at 2450 MHz is adjusted by the plasma adjusting plunger 8 to generate a plasma discharge around the substrate 5 in the reaction vessel 1, and the plasma discharge activates the heating of the reaction mixture gas and the substrate In this method, an artificial diamond coating layer is formed on the surface of the substrate by increasing the surface temperature and allowing the reaction to proceed for a predetermined time while maintaining the substrate surface temperature at 600 to 1000 ° C.

The artificial diamond coating layer formed on the substrate surface by these methods has an average layer thickness of 1 to 10 μm, and 0.1 to 3 μm.
m.

Further, when an artificial diamond coating layer is formed on the surface of various cutting tool members or wear-resistant tool members by using the above-described method, in order to improve the adhesion strength, Japanese Patent Laid-Open No.
As described in, for example, JP-A-166402 and JP-A-58-122692, as an intermediate layer, a metal carbide layer such as titanium nitride formed using a chemical vapor deposition method or a physical vapor deposition method, or an amorphous layer. A method of interposing a high quality carbon layer has also been proposed.

[Problems to be Solved by the Invention] On the other hand, in recent years, various machines have been improved in speed and performance,
In addition to the labor saving, cutting tool members used for this, and wear-resistant tool parts such as dies and dies are required to exhibit even more excellent wear resistance over a long period of time. Not only the artificial diamond coating layer formed by the above methods (1) to (3) but also the artificial diamond coating layer formed via the above-mentioned intermediate layer has insufficient adhesion strength to the substrate surface. At present, it is impossible to satisfy these demands.

[Means for solving the problem]

In view of the above, the present inventors have conducted research to improve the adhesion strength of the artificial diamond coating layer to the surface of the substrate, and as a result, have determined that the material of the substrate tool member is tungsten carbide (hereinafter, referred to as WC). ) Base cemented carbide and titanium carbonitride (hereinafter referred to as TiCN) based cermet, and on the surface thereof, the above-mentioned methods (1) to (3) are used, and the average layer thickness as an intermediate layer is as follows: 0.01 to 1 μm, and an average particle size: 0.005 to 0.046 μm to form a fine-grained artificial diamond coating layer, then the average layer thickness: 1 to 10 μm,
When an ordinary artificial diamond layer having an average particle diameter of 0.1 to 3 μm is formed, the adhesion strength of the intermediate artificial diamond coating layer to the substrate surface and the ordinary surface diamond coating layer is extremely high, and as a result, under severe conditions, In practical use, the artificial diamond coating layer is free from peeling and the like, and has been shown to exhibit excellent wear resistance over a long period of time.

The present invention has been made based on the above research results, and has an average layer thickness of 0.01 to 1 μm on the surface of a hard sintered alloy substrate made of a WC-based cemented carbide or a TiCN-based cermet, and 0.00 in particle size
Through an intermediate artificial diamond layer composed of fine grains of 5 to 0.046 μm, having an average layer thickness of 1 to 10 μm and an average particle size of 0.1 to
The present invention is characterized by an artificial diamond-coated hard sintered alloy member having a high adhesion strength, which is obtained by coating a surface artificial diamond layer composed of ordinary grains of 3 μm.

In the artificial diamond-coated hard sintered member of the present invention, the above-mentioned intermediate artificial diamond layer is formed when the above-mentioned normal grain surface artificial diamond layer is formed using the above-mentioned methods (1) to (3). On the other hand, it can be formed under the conditions that the pressure of the hydrocarbon in the reaction mixture gas and the substrate surface temperature are increased while the atmospheric pressure is relatively lowered.

Next, the reason why the average layer thickness and the average particle size of the intermediate and surface artificial diamond layers are limited as described above in the artificial diamond-coated hard sintered tool member of the present invention will be described.

(A) Intermediate artificial diamond layer (i) Average layer thickness If the layer thickness is less than 0.1 μm, it is not possible to secure a desired strong adhesion strength, while if the layer thickness exceeds 1 μm, fine grains are formed. Therefore, the accumulation of thermal stress generated at the crystal grain boundaries mainly due to the difference in the coefficient of thermal expansion between the substrate and the substrate becomes large and the layer easily breaks due to this. Therefore, the average layer thickness is set to 0.01 to 1 μm. .

(Ii) Average particle size When the particle size is less than 0.005 μm, the layer tends to be amorphous without a crystal grain boundary, so that not only the strength of the layer itself significantly decreases, but also the adhesion strength decreases. Become
On the other hand, even if the particle size exceeds 0.046 μm, the adhesion strength particularly to the surface of the substrate is reduced. Therefore, the average particle size is set to 0.005 to 0.046 μm.

(B) Surface artificial diamond layer (i) Average layer thickness If the layer thickness is less than 1 μm, the desired wear resistance cannot be secured, while if the layer thickness exceeds 10 μm, chipping or chipping occurs in the coating layer. Therefore, the average layer thickness is also set to 1 to 10 μm.

(Ii) Average particle size When the particle size is less than 0.1 μm, the abrasion resistance decreases, while when the particle size exceeds 3 μm, the adhesion strength to the intermediate artificial diamond layer decreases. For this reason, the average particle size was determined to be 0.1 to 3 μm.

〔Example〕

Next, the artificial diamond-coated hard sintered tool member of the present invention will be specifically described with reference to examples.

As a hard sintered tool substrate, a throw-away insert having the composition shown in Table 1 and the shape of CIS / SPP422 was prepared, and the surface of the insert was subjected to a scratching treatment using diamond powder having an average particle diameter of 10 μm. In this state, this was charged into an apparatus for thermionic emission material, an apparatus for high-frequency plasma discharge, and an apparatus for microwave plasma discharge, which are apparatuses for carrying out the above methods (1) to (3). Under the conditions shown in Table ₂ (the reaction mixture gas is composed of CH ₄ and H ₂ ), the intermediate and surface artificial diamond layers are formed to form an artificial diamond coated hard layer having an average layer thickness and an average particle diameter also shown in Table 1. Diamond coated cutting tips 1 to 6 of the present invention and comparative diamond coated cutting tips 1 to 6 as sintered tool members were produced, respectively.

In the comparative diamond-coated cutting tips 1 to 6, whether or not an intermediate artificial diamond layer is formed, and if any, at least one of the average layer thickness and the average particle size of the surface artificial diamond layer is determined by the present invention. Is out of the range.

Next, for the various diamond-coated cutting tips obtained as a result, Work material: Al-12% Si alloy, Cutting speed: 1000m / min, Feed: 0.1mm / tooth, Depth of cut: 1mm Perform wet milling test of Al alloy under the conditions of The time was measured. Table 1 shows the results of these measurements.

〔The invention's effect〕

From the results shown in Table 1, all of the diamond-coated cutting tips 1 to 6 of the present invention have extremely high adhesion strength of the artificial diamond layer to the substrate surface, and thus have a very long service life without peeling. hand,
In each of the comparative diamond-coated cutting tips 1 to 6, it is clear that the diamond layer is peeled off in a relatively short time, and the service life is extended.

As described above, the artificial diamond-coated hard sintered tool member of the present invention has a remarkably high adhesion strength of the artificial diamond layer constituting the tool member to the substrate surface, so that it can be peeled off even in practical use under severe conditions. Therefore, when this is applied, for example, as a cutting tool member or a wear-resistant tool member, it has industrially useful characteristics such as exhibiting excellent performance over a long period of time.

[Brief description of the drawings]

1, 2 and 3 are schematic sectional views showing an apparatus for forming an artificial diamond layer. DESCRIPTION OF SYMBOLS 1 ... Reaction container, 2 ... Reaction mixed gas introduction pipe, 3 ... Filament as a thermionic emission material, 4 ... Base plate, 5 ... Base.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Eto 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Metals Central Research Laboratory (72) Inventor Hironori Yoshimura 1-27-20 Nishishinagawa, Shinagawa-ku, Tokyo Mitsubishi (56) References JP-A-3-197677 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 16/00-16/56 C04B 41 / 87

Claims (1)

(57) [Claims] 1. A hard sintered tool base comprising a tungsten carbide-based cemented carbide or a titanium carbonitride-based cermet, having an average layer thickness of 0.01 to 1 μm and an average particle size of 0.005
Having an average layer thickness of 1 to 10 μm and an average particle size of 0.1 to 3 via an intermediate artificial diamond layer composed of fine particles of 0.046 μm.
An artificial diamond-coated hard sintering tool member having a high adhesion strength and coated with a surface artificial diamond layer composed of normal grains of μm.