JPH10310878A - Cutting tool made of surface-coated cemented carbide having hard coating layer excellent in wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provided a cutting tool made of a surface-coated cemented carbide in which a hard coating layer shows excellent wear resistance. SOLUTION: This coated-cemented carbide is the one in which, on the surface of a WC base cemented carbide base material, a hard coating layer consisting of a Ti compound layer composed of one or >= two kinds among a Tic layer, a TiN layer, a TiCN layer, a TiCO layer, a TiNO layer and a TiCNO layer and an Al2 O3 layer is applied by chemical vapor deposition and/or physical vapor deposition. In this case, the average layer thickness of the hard coating layer is thickened to 30 to 300 μm, and an excised face in which >= three cross- sectional layers among the structural layers of the hard coating layer are exposed is formed on the side of the cutting face of the ridgeline part of the cutting edge, along which the cutting face crosses flank of the cutting edge or from the side of the cutting face of the ridgeline part of the cutting edge to the side of the flank.

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
iC) layer, titanium nitride (hereinafter also indicated as TiN) layer, titanium carbonitride (hereinafter indicated as TiCN) layer, titanium carbonate (hereinafter indicated as TiCO) layer, titanium oxynitride (hereinafter referred to as TiNO) shown) layer, and titanium oxycarbonitride (hereinafter, 3 to 20 [mu] m and Ti compound layer comprising one or two or more of the illustrated) layer TiCNO, the hard coating layer consisting of the the Al ₂ O ₃ layer It is also known that coated carbide tools obtained by chemical vapor deposition and / or physical vapor deposition with an average layer thickness of, for example, are used for continuous or interrupted cutting of steel, for example. ing.

[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 To form a cut surface in which three or more cross-sectional layers of the constituent layers of the hard coating layer are exposed, and when cutting is performed in this state, the three or more exposed cross-sectional layers are simultaneously formed from the start of cutting. These three are involved in cutting.
The properties of each of the more than two layers are fully exhibited from the start of cutting.As a result, coated carbide tools can be used for high-speed cutting of heat-resistant alloys such as Inconel and Hastelloy, as well as difficult-to-cut materials such as stainless steel. Even if it did, the progress of wear was remarkably suppressed, especially the growth of boundary wear was extremely small, and excellent wear resistance was exhibited.

The present invention has been made on the basis of the above research results, and a TiC layer and a T
Ti comprising one or more of an iN layer, a TiCN layer, a TiCO layer, a TiNO layer, and a TiCNO layer
In a coated cemented carbide tool formed by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of a compound layer and an Al ₂ O ₃ layer, the hard coating layer has an average layer thickness of 30 to 300 μm.
m and the thickness of the hard coating layer from the rake face side of the cutting edge ridge portion where the rake face and the flank face of the cutting edge intersect, or from the rake face side of the cutting edge ridge portion to the flank face. The present invention is characterized by a coated carbide tool having a hard coating layer having excellent wear resistance, wherein a cut surface where three or more cross-sectional layers of the layers are exposed is formed.

[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 (the same in weight ratio, hereinafter, TiC / WC = 30/70) powder,
1.2 μm (Ti, W) CN (TiC / TiN / W
C = 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, wet-mixed in a ball mill for 72 hours, and dried. After that, ISO ・ CNMG12040
The compacts were press-molded into compacts having the shape specified in No. 8, and the compacts were vacuum-sintered under the conditions shown in Table 1 to produce super hard substrates A to E, respectively. Further, with respect to the super-hard substrate B, in a 100 Torr CH ₄ gas atmosphere,
Temperature: maintained at 1400 ° C. for 1 hour, then subjected to a slow cooling carburizing treatment, and after the treatment, carbon and Co adhering to the surface of the cemented carbide substrate were removed from the surface by acid and barrel polishing.
At a position of 1 μm, a Co-enriched zone having a maximum Co content of 15.9% by weight and a depth of 42 μm was formed on the surface of the substrate.
In addition, the sintered body A is still sintered,
Maximum Co content at a position 17 μm from the surface on the surface:
9.1% by weight, a Co-enriched zone having a depth of 23 μm, and a super-hard substrate D having a maximum Co at a position 17 μm from the surface.
A Co-enriched zone having a content of 10.9% by weight and a depth of 25 μm was formed, and the remaining cemented carbide substrates C and E did not have the Co-enriched zone and were generally homogeneous. Had a strong organization. Table 1 shows the internal hardness (Rockwell hardness A scale) of each of the superhard substrates A to E.
Are shown respectively.

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 a hard coating layer composed of a Ti compound layer and an Al ₂ O ₃ layer as shown in FIG. 2, comparative coated carbide tools 1 to 9 were respectively manufactured. In addition,
In comparative coated carbide tools 1 to 9, the thickness of the hard coating layer was made relatively thicker than that of the conventional coated carbide tool.

Next, for each of the comparative coated carbide tools 1 to 9 obtained as a result, as shown in FIG. 1, the rake face side of the cutting edge ridge line 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 of the cutting edge ridge portion with a rake face side width, a flank face width, and an R (radius) value as shown in Table 4, and the hard coating is formed. The coated carbide tools 1 to 9 of the present invention were produced by exposing three or more cross-sectional layers among the constituent layers of the layers. 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 9 of the present invention and comparative coated carbide tools 1 to 9, 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]

According to the results shown in Tables 3 to 5, the coated carbide tool of the present invention 1 in which the cut surface exposing three or more cross-sectional layers of the constituent layers of the hard coating layer is formed at the cutting edge ridge portion. 9
In any case, since the three or more cross-sectional layers exposed on the cut surface are simultaneously involved in the cutting, the comparative coated carbide tool 1 having no cut surface even in high-speed cutting of inconel or stainless steel which is a difficult-to-cut material. It is apparent that the progress of wear of the flank wear is relatively slower than that of Nos. 9 to 9, 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 vertical 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.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C23C 14/08 C23C 14/08 A 16/30 16/30

Claims (1)

[Claims] 1. One of a titanium carbide layer, a titanium nitride layer, a titanium carbonitride layer, a titanium carbonate layer, a titanium oxynitride layer, and a titanium carbonitride oxide layer on a surface of a tungsten carbide-based cemented carbide substrate. Alternatively, 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 a Ti compound layer composed of two or more kinds and an aluminum oxide layer, After increasing the thickness to 30 to 300 μm, the rake face of the cutting edge ridge line where the rake face of the cutting edge and the flank face intersect, or from the rake face side of the cutting edge ridge to the flank face, A cutting tool made of a surface-coated cemented carbide, in which a hard coating layer exhibits excellent wear resistance, wherein a cut surface exposing three or more cross-sectional layers of the constituent layers of the coating layer is formed.