JPH1190737A - Endmill made of surface coated super-hard alloy with hard coating layer excellent in adhesion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endmill made of surface coated super-hard alloy with a hard coating layer excellent in adhesion. SOLUTION: This endmill made of surface coating super-hard alloy is formed by forming a hard covering layer composed of a Ti compound layer formed of one kind or more than one kind among a TiC layer, a TiN layer, a TiCN layer, a TiNO layer, a TiCO layer, and a TiCNO layer, and an Al2 O3 layer in an average layer thickness of 0.5 to 4.5 μm by means of chemical vapor deposition and/or physical vapor deposition on a cutting edge part of a WC group super-hard alloy base body comprising the cutting edge part and a shank part. In this case, the Ti compound layer comprising the hard covering layer is formed being gradually reducing its thickness from the cutting edge part to the shank part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hard coating layer having excellent adhesion to a tungsten carbide-based cemented carbide substrate (hereinafter simply referred to as a substrate) and excellent wear resistance over a long period of time. The present invention relates to an end mill made of a surface-coated cemented carbide (hereinafter referred to as a coated cemented carbide end mill) exhibiting the following.

[0002]

2. Description of the Related Art Conventionally, a coated carbide end mill generally comprises a cutting edge portion and a shank portion as shown in FIG. Layers, nitride layers, carbonitride layers, carbonate layers, nitride layers,
And a carbonitride layer (hereinafter referred to as TiC layer and TiN layer, respectively)
Layer, TiCN layer, TiCO layer, TiNO layer, and Ti
A CNO layer) and an aluminum oxide layer (hereinafter referred to as Al ₂ O).
The hard coating layer composed of a indicated by ₃ layers) 0.5 to 4.5
It is well known to have chemical and / or physical vapor deposited structures with an average layer thickness of μm. Further, as shown in the schematic front view of the coated carbide end mill, a part of which is notched in FIG. Inserted into a through hole having the same diameter as the outer diameter of the shank, and supported upright in a state where the cutting edge is exposed, and inserted into a chemical vapor deposition device or a physical vapor deposition device in this state, to the cutting edge of the base. It is also known to be manufactured by forming a hard coating layer.

[0003]

On the other hand, cutting in recent years tends to be highly precise in combination with the high performance of cutting equipment, and accordingly, coated carbide end mills have been reduced in diameter and length. However, as the diameter and length of the coated carbide end mill become thinner and longer, the "deflection" at the time of cutting becomes larger, and as a result, the hard coating layer is more likely to peel off. At present, the service life is reached in a relatively short time due to the delamination of the layer.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the viewpoints described above, as a result of conducting research to improve the adhesion of the hard coating layer, upon deposition of the hard coating layer on the substrate surface, as shown in a partially cutaway schematic front view in FIG. When the base is supported in a state where the diameter of the through hole formed on the upper surface of the support box is larger than the diameter of the shank portion, and the hard coating layer is formed on the cutting edge portion in this state, a partial cutout is shown in FIG. As shown in the front view, a hard coating layer whose thickness gradually decreases from the cutting edge portion to the shank portion is formed. In this case, the shank portion of the hard coating layer is adjusted by adjusting the diameter of the through hole. However, the formation of the hard coating layer on the shank portion is possible only for the Ti compound layer, and the formation of the Al ₂ O ₃ layer on the shank portion in this state is impossible. Thus, the hard coating layer The coated carbide end mill in which the thickness of the Ti compound layer formed gradually decreases from the cutting edge portion to the shank portion, since the hard coating layer has excellent adhesion, the hard coating layer does not peel off and is excellent. The research results showed that the cutting performance would be remarkably exhibited over a long period of time.

The present invention has been made on the basis of the above-mentioned research results, and a TiC layer, a TiN layer, a TiCN layer, a TiC layer,
A hard coating layer composed of a Ti compound layer composed of one or more of an O layer, a TiNO layer, and a TiCNO layer and an Al ₂ O ₃ layer with an average layer thickness of 0.5 to 4.5 μm. In a coated cemented carbide end mill formed by chemical vapor deposition and / or physical vapor deposition, the Ti compound layer constituting the hard coating layer is formed by gradually decreasing the thickness from the cutting edge to the shank to form a close contact with the hard coating layer. It is characterized by a coated carbide end mill with improved properties.

[0006] In the coated carbide end mill of the present invention, the average thickness of the hard coating layer at the cutting edge is 0.5 to 0.5.
The reason why the thickness is limited to 4.5 μm is that if the thickness is less than 0.5 μm, the desired effect of improving the wear resistance by the hard coating layer cannot be obtained, while if the thickness exceeds 4.5 μm, the cutting edge This is because chipping (minute chipping) easily occurs, and the use life is shortened due to the chipping.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide end mill of the present invention will be specifically described with reference to examples. As the raw material powder, WC powder, TiC powder, ZrC powder, Ta, and the like each having a predetermined average particle size in the range of 0.1 to 1.5 μm.
C powder, NbC powder, VC powder, Cr ₃ C ₂ powder, and Co powder were prepared, and these raw material powders were blended in the composition shown in Table 1, wet-mixed with a ball mill for 24 hours, dried, and dried to 1 ton. / Cm ^{2 at} a pressure of 0.1 torr.
Vacuum sintering is carried out at a predetermined temperature in the range of 0 to 1500 ° C. for one hour, and the resulting sintered body is machined by
Cutting edge length: 20 mm x shank length: 130 mm x
Shank diameter: 6mm × Surface radius of cutting edge: 3mm
Substrates A to J were manufactured by finishing a long straight shank two-flute ball end mill having the following dimensions.

Next, as shown in FIG. 2, each of the substrates A to J is supported by a support box having variously different through-hole diameters. A hard coating layer having the composition and the average thickness shown in Table 2 was formed on the cutting edge surfaces of the substrates A to J (in this case, an Al ₂ O ₃ layer) using an arc ion plating apparatus which is one type of the apparatus. Other Ti compound layers are also formed on the shank portion in accordance with the diameter of the through hole of the support box) to thereby form the coated carbide end mill (hereinafter referred to as the coated end mill of the present invention) 1 to 10 of the present invention. Each was manufactured. In addition, for the purpose of comparison, as shown in FIG. 4, except that a support box having the same diameter of the through hole as the diameter of the shank portion was used, the cutting edge portion of the base was the same under the same conditions as shown in Table 2. By forming a hard coating layer on the substrate, conventional coated carbide end mills (hereinafter referred to as conventional coated end mills) 1 to 10 were respectively manufactured.

As described above, with respect to the various coated end mills obtained as described above, a position of 10 mm from the end face of the shank portion having a length of 130 mm as described above (hereinafter referred to as an end) and a position of 70 mm from the end face (hereinafter referred to as a center). And the average thickness of the hard coating layer at a position 125 mm from the end face (hereinafter, referred to as a portion adjacent to the cutting edge). Table 3 shows the results.

Further, using the above various coated end mills, work material: SKD11 (hardness: HR C48), cutting speed: 377 m / min, feed: 4000 mm / min, axial cut: 0.5 mm, cutting form : Dry cutting of alloy steel was performed under the following conditions: and cutting groove length until the flank wear width of the cutting edge reached 0.3 mm was measured. The measurement results are shown in Table 3.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

[0014]

From the results shown in Table 3, all of the coated end mills 1 to 10 of the present invention show no abrasion in the hard coating layer, show normal wear, and exhibit excellent cutting performance.
It is clear that the conventional coated end mills 1 to 10 all show a relatively short processing groove length, while the conventional coated end mills 1 to 10 all exhibit peeling of the hard coating layer, while exhibiting a long processing groove length. . As described above, the coated carbide end mill of the present invention significantly improves the adhesion of the hard coating layer, and therefore can sufficiently cope with the reduction in the diameter and length of the hard coating layer. It contributes to the conversion.

[Brief description of the drawings]

FIG. 1 is a partially cutaway schematic front view of a coated carbide end mill of the present invention.

FIG. 2 is a partially cutaway schematic front view showing a form of forming a hard coating layer of the coated carbide end mill of the present invention.

FIG. 3 is a partially cutaway front view of a conventional coated carbide end mill.

FIG. 4 is a partially cutaway schematic front view showing a hard coating layer forming mode of a conventional coated carbide end mill.

Claims (1)

[Claims] 1. A carbide layer, a nitride layer, a carbonitride layer, a nitrided oxide layer, a carbonated oxide layer of Ti, a titanium carbide layer, a nitride layer, a carbonitride layer,
And a hard coating layer composed of an aluminum oxide layer and a Ti compound layer composed of one or more of carbon oxynitride layers, and a chemical vapor deposition and / or an average layer thickness of 0.5 to 4.5 μm. In a surface-coated cemented carbide end mill formed by physical vapor deposition, a hard coating layer characterized by being formed by gradually reducing the thickness of the Ti compound layer constituting the hard coating layer from the cutting edge portion to the shank portion. Surface-coated cemented carbide end mill with excellent adhesion.