JPS6031999B2 - Composite tip for cutting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting composite tip that has good conductivity for heat generated during cutting.

Conventionally, one or two of carbides, nitrides, and carbonitrides of metals in the umbrella, &, and group of the periodic table are conventionally used.
A highly hard and extremely chemically stable cubic crystal structure is mounted on a support chip made of sintered super-alloy whose main components are ferrous metals and one or more iron group metals. Cutting tips made of carbon nitride (hereinafter abbreviated as CBN) or diamond-based sintered bodies may be simultaneously bonded during sintering of the cutting tips under ultra-high pressure and high temperature, or each may be bonded using a material such as Co. Composite cutting tips bonded or made using bonding metals are well known. The sintered support chip and sintered cutting chip in this composite chip are:
The ballability of the supporting tip provides excellent wear resistance, but it compensates for the lack of toughness of the sintered cutting tip. Usually, this composite tip is made of tungsten carbide-based cemented carbide. Alternatively, it is put into practical use by being attached to a predetermined position of a cutting tool alloy such as an Fe-based alloy by brazing or the like. However, in the above-mentioned conventional cutting composite tip, although the cutting tip constituting it has relatively good thermal conductivity, the supporting tip has relatively poor thermal conductivity. When used for cutting hardened steel, the supporting tip prevents conduction of the high heat generated in the cutting tip to the alloy, which not only softens the cutting tip due to the accumulated heat but also reduces the ballability of the supporting tip. This caused deterioration and shortened chip life.

The present invention provides a composite tip that solves the problems of the conventional composite cutting tips mentioned above, in which a cutting tip made of a CBN-based heating element or a cutting tip made of a diamond-based sintered body is supported by a cemented carbide alloy. In a composite chip for cutting which is bonded onto a chip, the support chip is provided with one or more through holes filled with a material with good thermal conductivity, so that the heat generated in the cutting chip during cutting can be reduced. A composite tip that achieves heat transfer and dissipation to the alloy through a material with good thermal conductivity in the supporting tip, which enables application to high-load cutting that involves high heat generation, and significantly extends the service life. It has the following characteristics.

Next, the composite chip of the present invention will be specifically explained using examples.

Example 1 8% by volume of CBN powder with a particle size distribution in the particle size range of 2-6 degrees and 15% by volume of Co powder with an average grain size of 3 degrees are mixed with hexane in a ball mill. After wet-mixing for 6 hours using as a solvent and heating and drying in vacuum, this mixed powder has the outer diameter shown in the perspective view in Fig. 1:
A powder compact A' of a disc-shaped cutting tip material having dimensions of 10 ribs x height: 1.5 legs was molded by stamping.

On the other hand, as shown in the perspective view in Fig. 2, it has dimensions of 1 x 3 x height, and Co: 8.
Volume %, WC: A disc-shaped support chip material B made of cemented carbide having a composition consisting of the remainder is provided with 12 through holes b with a diameter of 0.9 on the upper and lower surfaces thereof, This through hole b is made of a CBN-based firing body having a composition of CBN: 93% by volume and Cu: 5% by volume, and approximately 0% by volume. A rod-shaped highly thermally conductive material a having the outer diameter of the shoe rib was inserted to fill the through hole b. Next, the powder compact A' prepared in this way and the support chip material B are placed in a superimposed state in a capsule made of a high melting point metal, and placed in a girdle type ultra-high pressure container under a pressure of 5 arc b. , heating temperature: 1350o0,
Holding time: ultra-high pressure and high temperature treatment under conditions of 20 minutes,
A CBN-based scale cutting tip material A is placed on a WC-based cemented carbide supporting tip material B shown in a longitudinal cross-sectional view in FIG.
On the other hand, as shown in FIG. 4 in a vertical cross-sectional view, for comparison purposes, the supporting chip material B' was filled with a material with good thermal conductivity. A conventional composite chip material la' was manufactured under the same manufacturing conditions as the composite chip material la of the present invention described above, except that no through holes were provided.

Subsequently, both the resulting composite chip materials la, l
The composite chip of the present invention and the conventional composite chip, each of which has a triangular shape, are obtained by cutting a' along the dashed line and dividing it into four pieces, as shown in the bottom view of FIGS. 5a and 5, respectively. 1' were produced respectively.

Next, as shown in the perspective view in FIG.
The above-mentioned composite tip of the present invention and conventional composite tip 1' are each applied with silver solder to a triangular notch step at one of the four corners of the upper surface of the WC-based sintered cemented carbide cutting tool alloy C having a dimension of 5 ribs. After brazing and polishing, work material: die steel (hardness: HRC60), cutting speed: 12
0/min, Feed: 0.1 rib'rev to cutting depth: 0.3 rib, Cutting oil: Not used, Conditions (hereinafter referred to as cutting test 1), and Work material: S
NCM-8 (hardness: HRC52), cutting speed: 150 skin/min, feed: 0.2 willow/rev cutting depth: 0.8 fence, cutting oil: not used, conditions (hereinafter referred to as cutting test 2) A cutting test was carried out on each of the composite inserts, and the cutting time until the wear on the rake face of the composite tip reached 0.2 sails (hereinafter, life standard: VB = 0.2
The ribs) were measured.

The measurement results are shown in Table 1. -71- From the results shown in Table 1, it is clear that the cutting life can be extended by about twice as much by providing the support chip with a through hole filled with a material with good thermal conductivity.

In addition, when the temperature of the composite tip of both composite chips was measured at a point one yam away from the cutting edge by embedding a thermal haze pair, it was 72,000 for the composite chip of the present invention and 90,000 for the conventional composite chip 1'. It can be seen that the composite chip 1' has a much better thermal conductivity than the conventional composite chip 1'. Example 2 The material with good thermal conductivity filled in the through hole of the support chip was C
The composite chip of the present invention was produced under the same conditions as in Example 1 above, except that a CBN-based aggregate having a composition of BN: 95% by volume and Ag: 5% by volume was obtained.

2 and conventional composite chip 2 were manufactured, respectively.

Next, cutting tests 1 and 2 were conducted on both of the resulting composite chips under the same conditions as in Example 1, and the results shown in Table 2 were obtained.

As shown in Table 2, Example 2 also showed similar results to Example 1, and the composite chip of the present invention
It is clear that the cutting life is approximately twice as long as that of the secondary composite tip 2. M21 Example 3 After ultra-high pressure and high temperature treatment, a disc-shaped powder compact that becomes a cutting chip of a CBN-based sintered body was prepared using CBN powder having a particle size distribution in the particle size range of 2 to 4 grains: 70% by volume. , average particle size: TIN powder with 1 shake: 29% by volume, AI powder with the same particle size: 1% by volume
Composite chip 3 of the present invention was manufactured under the same conditions as in Example 1, except that the composition was composed of:

For comparison purposes, the support chip material was not provided with a through hole filled with a material with good thermal conductivity, and when subjected to ultra-high pressure and high temperature treatment, the above-mentioned green compact and the support chip material made of WC-based sintered cemented carbide were used. The conventional composite chip 3 was manufactured under the same manufacturing conditions as the above-described composite chip 3 of the present invention, except that a Co disk having a thickness of 0.3 skin was inserted between the overlapping surfaces of the composite chip 3.

Next, for both of the composite tips obtained as a result, work material: SNCM-8 (hardness: HRC54), cutting speed: 1
00/mjn, feed: 0.4 Yanagi/rev. , depth of cut: 0.6 willow, cutting oil: not used, life standard: VB=0.
Conditions on the second side (hereinafter referred to as cutting test 3) and work material:
Die steel (hardness HRC62), cutting speed: 80 skin/mi
n, feed: 0.12 ribs'rev. A cutting test was conducted under the following conditions: depth of cut: 0.3 ribs, cutting oil: not used, life standard: VB = 0.2 ribs (hereinafter referred to as cutting test 4), and the time required to reach the life standard was measured. .

The measurement results are shown in Table 3. As shown in Table 3, it is clear that the composite tip 3 of the present invention has a longer cutting life than the conventional composite tip 3.

3. In the above example, a case was described in which the cutting tip was made of a CBN-based composite, but the same results could be obtained even if the cutting tip was made of a diamond-based composite. The case has been described in which a C8N-based heat conductive material is used as the material with good thermal conductivity, but the material is not limited to this, and any material with good thermal conductivity may be used, such as diamond. Kikyo-kei, Ag, Cu
, Au, and W, or alloys thereof, can be used.

In addition, 1 part of the green compact that becomes the cutting chip after ultra-high pressure and high temperature treatment.
The bonding strength between the two chips may be improved by stacking the two chips in a state that they are inserted into the through hole of the support chip material and performing ultra-high temperature pressure and high temperature treatment. As mentioned above, according to the composite tip of the present invention, the heat generated in the cutting tip during cutting is not accumulated and is immediately transferred to the cutting tool alloy through the good thermal conductive material that fills the through hole of the support. Since the heat is dissipated from this, the hardness of the cutting tip will not decrease due to heat, and the ballability of the supporting tip will not deteriorate, so the cutting life can be significantly extended without being affected by cutting conditions. This brings about industrially useful effects such as measurement.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a green compact of the cutting tip material, Fig. 2 is a perspective view showing the supporting tip material, Fig. 3 is a longitudinal cross-sectional view showing the composite chip material of the present invention, and Fig. 4 is a conventional composite chip. 5A and 5B are bottom views showing how the composite chip material is cut, and FIG. 6 is a perspective view showing how the composite chip is attached to the alloy. A'... Green compact of cutting tip material, A... Cutting tip material, B, B'... Supporting tip material, b
...Through hole, a... Rod-shaped material with good thermal conductivity, la, la... Composite chip material, 1, 1'... Composite chip, C... Cutting Tool alloy. Hair' figure Tsutomu 2 figure *3 figure inferior 4 figure Tsutomu 5 figure 6 figure

Claims (1)

[Claims] 1. A cutting composite chip formed by bonding a cutting chip made of a cubic boron nitride-based sintered body or a cutting chip made of a diamond-based sintered body onto a support chip made of a cemented carbide, in which the support chip is provided with a thermally conductive material. A composite tip for cutting, which is provided with one or more through holes filled with a good material to facilitate the transfer and dissipation of heat generated in the cutting tip during cutting to the base metal through the supporting tip.