JPH09143607A - Cubic boron nitride base sintered compact excellent in high temperature strength - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cubic boron nitride (cBN)-base sintered compact exhibiting superior effects when used as a high speed intermittent cutting tool for hardened steel and excellent in high temp. strength. SOLUTION: This sintered compact is a cBN-base sintered compact having a composition consisting of, by volume, 10-30% of one or >=2 kinds among the carbides, nitrides, and carbonitrides of Ti, Zr, Hf, V, Nb, and Ta, 10-20% of (Ti1-x Vx )(C1-y Ny ) (where x=0.1 to 0.4 and y=0.1 to 0.5 are satisfied), 1-10% of either or both of NbAl intermetallic compound and TaAl intermetallic compound, and the balance cBN, and further, this sintered compact is a cBN-base sintered compact prepared by further incorporating 1-10vol.% of one or >=2 kinds among Al2 O3 , AlN, and AlB2 into the cBN-base sintered compact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cubic boron nitride (hereinafter referred to as "cBN")-based sintered body excellent in high-temperature strength. This cBN-based sintered body is particularly suitable for hardened steel. It has excellent effects when used as a high-speed intermittent cutting tool.

[0002]

2. Description of the Related Art A cBN-based sintered body has a hardness close to that of diamond and has extremely low reactivity with an iron group metal. It can be cut and has been widely used as a cutting tool in recent years.

As the cBN-based sintered body, Ti, Zr,
One or more of Hf, V, Nb, and Ta carbides, nitrides, and carbonitrides are mainly used, and Ti is further added.
And one or two of the intermetallic compounds of Al and
A cBN-based sintered body, the rest of which is cBN, is known (see JP-A-53-77811). Furthermore, Ti
One or two of the following carbides, nitrides, and carbonitrides
Species or higher: 1 to 20% by volume, intermetallic compound of Co and Al:
CBN containing 1 to 10% by volume, the rest consisting of cBN
A base sintered body is also known (see JP-A-60-145351).

[0004]

[Problems to be Solved by the Invention] However, these cB
Since the N-based sintered body lacks high-temperature strength, when the hardened steel is subjected to high-speed intermittent cutting at a cutting speed of 150 m / min or more, the cutting tool is severely damaged and the tool life is short. It was

[0005]

Accordingly, the present inventor has conducted research to obtain a cBN-based sintered body having higher high-temperature strength than conventional ones. As a result, (a) Ti, Zr, Hf, V, Nb, T
One or more of the carbides, nitrides, and carbonitrides of a: 10 to 30% by volume, (Ti _1-x V _x ) (C
_{1-y N y) (x} : 0.1~0.4, y: 0.1~0.
5): 10 to 20% by volume, one or two of Nb and Al intermetallic compound and Ta and Al intermetallic compound:
CB containing 1 to 10% by volume, the rest being cBN
N-based sintered body, (b) Ti, Zr, Hf, V, Nb, Ta
One or two of the following carbides, nitrides, and carbonitrides
Species or higher: 10 to 30% by volume, (Ti _1-x V _x ) (C _{1-y
N y) (x: 0.1~0.4,} y: 0.1~0.5):
10-20% by volume, intermetallic compound of Nb and Al and T
One or two of the intermetallic compounds of a and Al: 1-1
0% by volume, 1 of Al ₂ O ₃ , AlN and AlB ₂
Or 2 or more kinds: 1 to 10% by volume, and a cBN-based sintered body comprising the rest of cBN has higher high-temperature strength than conventional ones. Therefore, using this cBN-based sintered body as a cutting tool The inventors have found that even if high-speed intermittent cutting of hardened steel is performed at a cutting speed of 150 m / min or more, the cutting tool is not damaged.

The present invention has been made on the basis of such findings, and (1) Ti, Zr, Hf, V, Nb,
One or more of Ta carbides, nitrides, and carbonitrides: 10 to 30% by volume, (Ti _1-x V _x ) (C
_{1-y N y) (x} : 0.1~0.4, y: 0.1~0.
5): 10 to 20% by volume, one or two of Nb and Al intermetallic compound and Ta and Al intermetallic compound:
1 to 10% by volume, cBN-based sintered body excellent in high-temperature strength containing the rest of cBN, (2) Ti, Zr, H
One or more of carbides, nitrides, and carbonitrides of f, V, Nb, and Ta: 10 to 30% by volume, (Ti
_1-x V _x ) (C _1-y N _y ) (x: 0.1-0.4, y:
0.1 to 0.5): 10 to 20% by volume, one or two of the intermetallic compound of Nb and Al and the intermetallic compound of Ta and Al: 1 to 10% by volume, and further, Al ₂
This is characterized by a cBN-based sintered body containing one or more of O ₃ , AlN and AlB ₂ or more: 1 to 10% by volume, and the balance being cBN, which is excellent in high temperature strength. .

The cBN-based sintered body according to the above (1) or (2) is used as a cutting tool and hardened steel is cut at a cutting speed of:
The present invention is also characterized by the cBN-based sintered body cutting tool as described in (1) or (2) above, because the cutting tool does not break even after high-speed intermittent cutting at 150 m / min or more. is there.

T constituting the cBN-based sintered body of the present invention
If one or more of i, Zr, Hf, V, Nb, Ta carbides, nitrides, and carbonitrides are less than 10% by volume, high-temperature strength is insufficient, while if more than 30% by volume, It is not preferable because the hardness decreases. Therefore, Ti,
The content of one or more of Zr, Hf, V, Nb, and Ta carbides, nitrides, and carbonitrides is 10 to 3.
It was set to 0% by volume. CBN excellent in high temperature strength of the present invention
Ti, Zr, Hf, V, Nb, Ta contained in the base sintered body
One or two of the following carbides, nitrides, and carbonitrides
A more preferable range of one or more kinds is 15 to 27% by volume.

The cBN-based sintered body of the present invention is constituted (T
i _1-x V _x ) (C _1-y N _y ) (x: 0.1 to 0.4,
y: 0.1 to 0.5), a more preferable range of x is 0.2 to 0.4, and a more preferable range of y is 0.
It is 3 to 0.5, and the content of this component is preferably 10 to 20% by volume, and more preferably 12 to 16.

Further, if less than 1% by volume of one or two of the intermetallic compound of Nb and Al and the intermetallic compound of Ta and Al is contained, there is no effect of improving high temperature strength.
If the content is more than 0% by volume, the high temperature strength will decrease, which is not preferable. Therefore, the content of one or two of the intermetallic compound of Nb and Al and the intermetallic compound of Ta and Al is set to 1 to 10% by volume. Nb and A contained in the cBN-based sintered body cutting tool excellent in high temperature strength of the present invention
A more preferable range of one or two of the intermetallic compound of 1 and the intermetallic compound of Ta and Al is 3 to 8% by volume.

The cBN-based sintered body of the present invention further comprises A
One or more of l ₂ O ₃ , AlN and AlB ₂ are contained, but the content is preferably 1 to 10% by volume, more preferably 2 to 6% by volume.

The cBN-based sintered body according to the present invention has, as raw material powder, cBN powder, Ti, Zr, Hf, V, Nb and Ta.
Carbide powder, nitride powder and carbonitride powder of Ti, V composite carbonitride powder of Ti and V, Nb and Al intermetallic compound powder and Ta and Al intermetallic compound powder, and Al ₂ O
₃ powders, AlN powders and AlB ₂ powders are prepared, these raw material powders are blended in a predetermined ratio, mixed and molded,
Obtained by ultra-high pressure and high temperature sintering.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As a raw material powder, an average particle diameter: 0.
8 μm cBN powder, average particle size: 0.5 μm Ti and V
Composite carbonitride powder, average particle size: 0.5 μm TiC powder, average particle size: 0.5 μm ZrC powder, average particle size:
0.5 μm HfC powder, average particle size: 0.5 μm VC
Powder, average particle size: 0.5 μm NbC powder, average particle size:
0.5 μm TaC powder, average particle size: 0.5 μm Ti
N powder, ZrN powder with an average particle size: 0.5 μm, HfN powder with an average particle size: 0.5 μm, VN powder with an average particle size: 0.5 μm, NbN powder with an average particle size: 0.5 μm, average particle size : 0.5 μm TaN powder, average particle size: 0.5 μm TiCN powder, average particle size: 0.5 μm ZrCN powder,
HfCN powder having an average particle size: 0.5 μm, average particle size: 0.
5 μm VCN powder, average particle size: 0.5 μm NbCN
Powder, TaCN powder having an average particle size of 0.5 μm, intermetallic compound powder of Nb and Al having an average particle size of 0.5 μm, intermetallic compound powder of Ta and Al having an average particle size of 0.5 μm, average particle size : 0.6 μm Al ₂ O ₃ powder, average particle size: 0.
5 μm AlN powder and average particle size: 0.5 μm Al
B ₂ powder is prepared, these raw material powders are blended and mixed,
The obtained mixed powder is pressure: 6 GPa, temperature: 1500
The present invention cB having the composition of the sintered body shown in Tables 1 to 5 by performing high-pressure high-temperature sintering under the condition of 30 ° C. and holding for 30 minutes.
N-based sintered bodies (hereinafter, referred to as the sintered body of the present invention) 1 to 36 were produced, and further, conventional cBN-based sintered bodies (hereinafter, referred to as conventional sintered body) 1 to 3 were produced for comparison. .

Each of the sintered bodies 1 to 36 of the present invention and the conventional sintered bodies 1 to 3 is cut into an equilateral triangle having a side of 5 mm and a thickness of 1 mm, and is brazed to a base of a chip shape: TNGA332, which is then formed into a PTGNL44M16 shape. The cutting tool is fixed to the holder of No. 3, and the work material is SCM415 (HRC65) with 8 grooves, cutting speed: 250 m / min, feed: 0.2 mm / rev, depth of cut: 0. A high-speed wet intermittent cutting test of hardened steel was performed under the conditions of 1 mm, cutting time: 30 min,
The flank wear width of the cutting tool and the time to fracture were measured, and the results are shown in Table 6.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

[Table 4]

[0019]

[Table 5]

[0020]

[Table 6]

[0021]

From the results shown in Tables 1 to 6, even if high speed wet intermittent cutting of hardened steel is carried out using the cutting tools produced from the sintered bodies 1 to 36 of the present invention, the conventional cutting tools 1 to 3 It can be seen that excellent high-temperature strength is exhibited from the fact that no defects occur like the cutting tool produced in 1. As described above, since the cBN-based sintered body of the present invention exhibits excellent high-temperature strength, it is possible to provide a cutting tool capable of cutting hardened steel under more severe conditions than conventional ones. It has an excellent effect.

Claims (3)

[Claims] 1. One or more of carbides, nitrides and carbonitrides of Ti, Zr, Hf, V, Nb and Ta: 10 to 30% by volume, (Ti _1-x V _x ). (C _1-y N _y ) (x: 0.1 to 0.
4, y: 0.1 to 0.5): 10 to 20% by volume, one or two of the intermetallic compounds of Nb and Al and the intermetallic compound of Ta and Al: 1 to 10% by volume. A cBN-based sintered body excellent in high-temperature strength, characterized in that it is contained and the rest is made of cubic boron nitride (hereinafter referred to as cBN). 2. One or more of Ti, Zr, Hf, V, Nb and Ta carbides, nitrides and carbonitrides: 10 to 30% by volume, (Ti _1-x V _x ). (C _1-y N _y ) (x: 0.1 to 0.
4, y: 0.1 to 0.5): 10 to 20% by volume, one or two of the intermetallic compounds of Nb and Al and the intermetallic compound of Ta and Al: 1 to 10% by volume, Al ₂ O _3, 1 or two of the AlN and AlB ₂
A cBN-based sintered body excellent in high-temperature strength, characterized in that it contains 1 to 10% by volume of the seeds and the rest is cBN. 3. A cutting tool made of a cBN-based sintered body, comprising the cBN-based sintered body excellent in high temperature strength according to claim 1 or 2.