JP3360565B2 - Surface coated cemented carbide cutting tool with a hard coating layer exhibiting excellent wear resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is, for example, heat-resistant alloys such as Inconel and Hastelloy, when further used in high-speed cutting of difficult-to-cut materials such as stainless steel, the Ti compound layer of aluminum oxide (hereinafter, Al ₂ O ₃ The present invention relates to a cutting tool made of a surface-coated cemented carbide (hereinafter referred to as a coated cemented carbide tool) in which a hard coating layer composed of a layer exhibits excellent wear resistance.

[0002]

2. Description of the Related Art Conventionally, as shown in a schematic vertical sectional view of a main part in FIG. 2, a surface of a tungsten carbide-based cemented carbide substrate (hereinafter, referred to as a cemented carbide substrate) is coated with titanium carbide (hereinafter, referred to as T).
of a Ti compound layer including an iC layer, a titanium nitride (hereinafter also indicated as TiN) layer, a titanium carbonate (hereinafter indicated as TiCO) layer, and a titanium carbonitride (hereinafter indicated as TiCNO) layer A hard coating layer composed of at least one of the following, a titanium carbonitride (hereinafter, referred to as TiCN) layer, and an Al ₂ O ₃ layer by chemical vapor deposition and / or physical vapor deposition with an average layer thickness of 3 to 20 μm. Is known, and it is also known that the coated carbide tool is used for continuous cutting or intermittent cutting of steel, for example.

[0003]

On the other hand, in recent years, high performance and high output of a cutting device have been remarkable, and there is a strong demand for labor saving. With this, cutting tends to be performed at a high speed. In the conventional coated cemented carbide tool, when this is used for high-speed cutting of a heat-resistant alloy such as Inconel and Hastelloy, and further, a difficult-to-cut material such as stainless steel, a flank surface as shown in FIG. In addition to the relatively rapid progress of wear in the wear width, the progress of boundary wear, particularly on the flank, is remarkable, so that at present the service life can be reached in a relatively short time.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoint, as a result of conducting research to develop a coated carbide tool having excellent wear resistance, the average thickness of the hard coating layer constituting the coated carbide tool was increased to 30 to 300 μm. As shown in the main part schematic vertical sectional view of FIG. 1, the rake face side of the cutting edge ridge portion where the rake face and the flank face of the cutting edge intersect, or the flank side from the rake face side of the cutting edge ridge line portion , One or more of the Ti compound layers constituting the hard coating layer, a TiCN layer, and an Al ₂ O ₃ layer.
Forming a cut surface in which more than one layer of the cross-section layer is exposed, and performing cutting in this state, the three or more cross-section layers exposed from the start of cutting will be involved in the cutting at the same time,
The properties of each of these three or more cross-sectional layers are fully exhibited from the start of cutting, and as a result, the coated carbide tool is
For example, high-speed cutting of heat-resistant alloys such as Inconel and Hastelloy, as well as difficult-to-cut materials such as stainless steel, significantly suppresses the progress of wear, and particularly, the growth of boundary wear is extremely small, exhibiting excellent wear resistance. The research results show that life can be significantly extended.

The present invention has been made on the basis of the above research results, and a TiC layer and a T
Ti consisting of an iN layer, a TiCO layer, and a TiCNO layer
One or more of the compound layers, a TiCN layer, and Al ₂ O
_In a coated cemented carbide tool obtained by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of _three layers, after increasing the average thickness of the hard coating layer to 30 to 300 μm,
From the rake face side of the cutting edge ridge portion where the rake face and flank face of the cutting edge intersect, or from the rake face side of the cutting edge ridge portion to the flank face, of the Ti compound layer which is a constituent layer of the hard coating layer And a hard coating layer having excellent wear resistance, wherein a cut surface exposing three or more cross-sectional layers of a TiCN layer and an Al ₂ O ₃ layer is exposed. It has features.

[0006] In the coated carbide tool of the present invention,
The reason for having three or more exposed cross-sectional layers in the hard coating layer is as follows.
As described above, in order to exhibit excellent wear resistance from the start of cutting, simultaneous involvement of three or more constituent layers having different characteristics is indispensable. Therefore, it is desirable when the number of exposed cross-sectional layers is two or less. This is because excellent wear resistance cannot be exhibited from the start of cutting, and as a result, it becomes difficult to suppress the progress of wear. The reason why the average thickness of the hard coating layer is set to 30 to 300 μm is that when the thickness is 30 μm, the thickness of the hard coating layer on the cut surface becomes relatively thin and the excellent wear resistance is obtained over a long period of time. When the thickness exceeds 300 μm,
This is because chipping or chipping (micro chipping) is likely to occur in the cutting blade.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide tool of the present invention will be specifically described with reference to examples. Medium-sized WC powder having an average particle diameter of 2.8 μm, 4.9 μm as the raw material powder
m of coarse WC powder, 1.5 μm of (Ti, W) C [weight ratio (mass ratio), same hereafter, TiC / WC = 30/7
0] powder, (Ti, W) CN (TiC /
TiN / WC = 24/20/56) powder, 1.2 μm
(Ta, Nb) C (TaC / NbC = 90/10) powder and Co powder of 1.1 μm were prepared, and these raw material powders were blended in the composition shown in Table 1, and wet-processed in a ball mill for 72 hours. After mixing and drying, ISO ・ CNMG
The compact was pressed into a compact having the shape defined by 120408, and the compact was vacuum-sintered under the same conditions as shown in Table 1 to produce super hard substrates A to E, respectively. further,
The above-mentioned super-hard substrate B is kept in a 100 Torr CH ₄ gas atmosphere at a temperature of 1400 ° C. for 1 hour, and then subjected to a slow cooling carburizing treatment. After the treatment, carbon and Co adhering to the super-hard substrate surface are removed. By removing with acid and barrel polishing,
A Co-enriched zone having a maximum Co content of 15.9% by weight and a depth of 42 μm was formed on the substrate surface at a position 11 μm from the surface. In addition, with the sintered body A still being sintered, the superhard substrate A had a Co-enriched zone having a maximum Co content of 9.1% by weight and a depth of 23 μm at a position of 17 μm from the surface on the surface.
The super-hard substrate D has a maximum Co content of 10.9% by weight and a depth of 25 μm at a position 17 μm from the surface.
Each enriched zone is formed and the remaining cemented carbide substrate C
The samples E and E did not have the Co-enriched zone and had an overall homogeneous structure. Table 1 shows the internal hardness (Rockwell hardness A scale) of each of the carbide substrates A to E.

Then, the surfaces of these super-hard substrates A to E are honed, and a conventional chemical vapor deposition apparatus is used. Table 1 (1-TiCN in the table corresponds to JP-A-6-8010
Under the conditions shown in Table 3, the composition and the average layer thickness shown in Table 3. By forming one or more of the above-mentioned Ti compound layers, a TiCN layer, and a hard coating layer composed of an Al ₂ O ₃ layer as shown in FIG. Was manufactured respectively. The comparative coated carbide tools 1 to 6 have hard coating layers which are relatively thicker than those of the conventional coated carbide tools.

Next, for each of the comparative coated carbide tools 1 to 6 obtained as a result, as shown in FIG. 1, the rake face side of the cutting edge ridge portion where the rake face and the flank face of the cutting edge intersect. Alternatively, a cut surface is formed from the rake face side to the flank face side of the cutting edge ridge line portion with the rake face side width, the flank face width, and the R (radius) value as shown in Table 4, and the hard surface is formed. By exposing three or more cross-sectional layers of a Ti compound layer, a TiCN layer, and an Al ₂ O ₃ layer, which are one of the constituent layers of the coating layer, each of the coated carbide tools 1 to 6 of the present invention is exposed. Manufactured. The number of exposed cross-section layers on the rake face and flank side in Table 4 are the results of observation of the coated carbide tool by plane observation on the rake side and front observation on the flank side, respectively.

Next, for the above-mentioned coated carbide tools 1 to 6 of the present invention and comparative coated carbide tools 1 to 6, a work material: a round bar of Inconel 718, a cutting speed: 100 m / min. , Depth of cut: 1 mm, feed: 0.3 mm / rev. Cutting time: 10 minutes, wet high-speed continuous cutting test of heat-resistant alloy under the following conditions: Work material: JIS SUS304 round bar, Cutting speed: 300 m / min. Infeed: 1.5 mm. Feed: 0.3 mm / rev. Wet high-speed continuous cutting tests were performed on stainless steel under the following conditions: cutting time: 10 minutes, and the maximum flank wear width and boundary wear width of the cutting edge were measured in each cutting test. Table 5 shows the results of these measurements.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

[0014]

[Table 4]

[0015]

[Table 5]

[0016]

As can be seen from the results shown in Tables 3 to 5, one or more of the above-mentioned Ti compound layers, which are constituent layers of the hard coating layer, a TiCN layer, and an Al ₂ O ₃ layer have three or more layers. The coated carbide tools 1 to 6 of the present invention in which the cut surface where the cross-sectional layer is exposed are formed in the cutting edge ridge portion are all the above-mentioned 3 exposed to the cut surface.
Since more than one layer is involved in cutting at the same time, even compared to comparative coated carbide tools 1-9 where the cut surface does not exist even in high-speed cutting of inconel or stainless steel, which is a difficult-to-cut material,
It is evident that the wear progress of the flank wear is relatively slow, and especially the growth of the boundary wear on the flank is extremely small, indicating excellent wear resistance. As described above, the coated cemented carbide tool of the present invention is not limited to continuous cutting or interrupted cutting under ordinary conditions such as heat-resistant alloys such as Inconel or stainless steel, and particularly, these cutting conditions are particularly severe. Even at high speeds, excellent wear resistance is exhibited over a long period of time, so that it can sufficiently cope with high-speed cutting and contributes to labor saving.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a main part of a coated carbide tool of the present invention.

FIG. 2 is a schematic longitudinal sectional view of a main part of a conventional coated carbide tool.

FIG. 3 is a schematic perspective view of a main part of a conventional coated carbide tool.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ identification code FI C23C 14/08 C23C 14/08 A 16/30 16/30 (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 28/04 B23B 27/14 B23P 15/28 C23C 14/06 C23C 14/08 C23C 16/30

Claims (1)

(57) [Claims] 1. A titanium compound layer comprising a titanium carbide layer, a titanium nitride layer, a titanium carbonate layer, and a titanium carbonitride layer on a surface of a tungsten carbide-based cemented carbide substrate.
In a surface-coated cemented carbide cutting tool obtained by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of at least one species, a titanium carbonitride layer, and an aluminum oxide layer, the average thickness of the hard coating layer After the thickness of the cutting edge is increased to 30 to 300 μm, the rake face of the cutting edge ridge portion where the rake face and the flank face of the cutting edge intersect, or the rake face side of the cutting edge ridge portion to the flank side, One or more Ti compound layers that are constituent layers of the coating layer, a titanium carbonitride layer,
A surface-coated cemented carbide cutting tool in which a hard coating layer exhibits excellent wear resistance, characterized in that a cut surface where three or more cross-sectional layers of an aluminum oxide layer are exposed is formed.