KR20030085870A - method of manufacture of insert for cutter tool - Google Patents

Abstract

PURPOSE: A method for manufacturing an insert for a cutting tool is provided to reduce manufacturing cost by forming a plurality of cutting blades simultaneously in only one sintering process, and to prevent sintered diamond and sintered CBN from being peeled from a cemented material. CONSTITUTION: A method for manufacturing an insert comprises the steps of: forming a plurality of circular spaces on a cemented material(3); filling the spaces with diamond powder and Cubic Boron Nitride(CBN) powder; sintering the cemented material under high temperature and ultrahigh pressure; and joining sintered diamond(5a) and sintered CBN(5b) to the cemented material, and forming a plurality of cutting blades, simultaneously.

Description

Method of manufacture of insert for cutter tool

The present invention relates to an insert used in a cutting tool, and more particularly, to inserting a plurality of diamond powder or CBN (Cubic Boron Nitride) powder into a cemented carbide forming a cutting insert. By sintering under pressure at high temperature and high pressure to obtain the sintered body of the cutting edge, it is possible to prevent the sintering of the diamond sintered body or CBN sintered body from the cemented carbide according to the strong bonding strength of the cemented carbide and the diamond sintered body or CBC sintered body. The present invention relates to a cutting insert suitable for having a low manufacturing cost since a cutting edge having a plurality of diamond sintered bodies or CBN sintered bodies can be simultaneously obtained by the sintering process.

In milling metals such as steel and cast iron, cutting operations are performed by attaching inserts to various rotary cutting tools such as face milling cutters, boring cutters, and seed cutters. Such cutting inserts are welded (brazing) diamond sintered body or CBN sintered body (2) manufactured by separately sintering to the outside of the corner of the cemented carbide (1), such as sintered in a rhombus, square or triangle shape as shown in Figs. Weld by the method to obtain an insert with unit pieces.

The diamond sintered body or CBN sintered body produced by the above method (2) The cutting tip is inevitably heated in the welding process to the diamond sintered body or CBN sintered body used at the cutting edge to a high temperature of 700 ~ 900 ℃, in this process The welding stress remains between the diamond sintered body or the CBN sintered body (2) and the cemented carbide material (1), and the deterioration problem of the sintered body due to high temperature oxidation of the diamond sintered body or CBN sintered body during the heating process occurs. do.

In order to prevent the high temperature oxidation, a method such as vacuum welding has been attempted, but the problem of residual thermal stress due to welding still exists even though the operation is not easy due to the high cost, so that the diamond sintered body or CBN sintered body and the cemented carbide material during the welding operation are still present. It provides a cause of the peeling phenomenon between the layers.

Therefore, commercially welding the diamond sintered or CBN sintered body (2) pieces and the cemented carbide material (1) is performed in 100% of the land. In this process, the sintered cutting edge damaged by high temperature oxidation is processed during the cutting edge. As a result of the above problem, the problem of the heating welding method is that the sintered body peeling phenomenon is caused by thermal stress as mentioned above, which is the diamond sintered body or the CBN sintered body and the cemented carbide layer. Due to the nature of this bonded double bond material, the diamond sintered body or CBN sintered body is often formed by the thermal stress generated at the support of the cemented carbide base material 1 having high thermal expansion and the diamond sintered body or CBN sintered body 2 when the welding heating process is performed. There is a problem such as causing the phenomenon that the cemented carbide material is peeled off, and also As the method has become a cause of increase of manufacturing cost because it can produce a multiple of the insert at the same time.

The present invention is to solve the above problems, by inserting the diamond powder or CBN powder in a plurality of spaces formed on the cemented carbide having a large diameter size by pressing and sintering to be synthesized in the ultra-high temperature and ultra-high pressure state, Inserts suitable for preventing peeling of diamond sintered body or CBN sintered body from cemented carbide according to the high bonding strength between diamond sintered body or CBN sintered body and cemented carbide based on cutting edge with multiple unit pieces in sintering process The purpose is to provide.

1 and 2 are cutting insert shape diagrams in which a conventional diamond sintered body or C.B.N sintered body pieces are joined by a brazing method

Figure 3 is a cross-sectional view showing the manufacturing state of the cemented carbide of the present invention

4 and 5 are state diagrams obtained by synthetically sintering a plurality of diamond sintered body or C.B.N sintered body according to the present invention with a cemented carbide material

FIG. 6 and FIG. 7 are shape views of cutting inserts cut into insert unit pieces required in FIGS. 4 and 5.

Explanation of symbols for main parts of the drawings

3: cemented carbide material 4. 4b: space part

5a, 5b: diamond sintered body or C.B.N sintered body

In the present invention for achieving the above object, in the insert having a diamond sintered body or CBN sintered body in the cemented carbide, a plurality of circular or semicircular spaces are secured to the cemented carbide, so that diamond powder or CBN powder is filled in the space. The powder-filled cemented carbide is synthetically sintered to a synthetic press under high temperature and high pressure to bond the cemented carbide and the diamond sintered or CBN sintered body to form a plurality of cutting edges at the same time. It consists of a method of manufacturing inserts for cutting tools characterized in that.

As conditions for the synthetic sintering, sintering is preferably performed at a high temperature of 1,300 to 1,600 ° C and 30,000 to 60,000 atmospheres (Pa).

According to the present invention, it is also possible to simultaneously attach various cutting edges of different sintered bodies having different physical properties to the space of the cemented carbide to be embedded with the diamond sintered body or CBN sintered body, so that the upper and lower surfaces of the same insert, which cannot be manufactured by the conventional welding method, are different. Sintering is possible by filling raw materials having physical properties.

Figure 3 shows the manufacturing state of the cemented carbide material according to the present invention, Figures 4 and 5 shows a structural diagram for forming a plurality of diamond sintered body or CBN sintered body (5a) (5b) in the space of the cemented carbide material (3). .

As shown in FIG. 3, the cemented carbide material 3 having a larger diameter than the conventional one is prepared by sintering separately. At this time, the cemented carbide material 3 is formed by providing the required number of spaces 4 and 4a of a predetermined size in which a plurality of diamond powders or C.B.N powders can be filled.

The spaces 4 and 4a may be formed in a circular or semi-circular shape according to the required shape of the diamond sintered body or the C.B.N sintered body, and the spaces may be formed on the upper surface or both the upper and lower surfaces.

Filling the diamond powder or CBN powder in the space portion (4) (4a) of the formed cemented carbide material, put it in a synthetic press (Press), ultra high temperature and ultra-high pressure state, that is 1300 ~ 1600 ℃ and 30,000 ~ 60,000 atmosphere (Pa) By pressing and sintering so as to be synthesized in the state of, the diamond sintered body or the CBN sintered body 5a, 5b is strongly bonded to the cemented carbide material 3 and bonded.

The raw material prepared as described above is cut and separated in the form of the insert unit pieces required as shown in FIGS. 6 and 7 by means of electric discharge machining or laser cutting to obtain a plurality of cutting inserts.

The spaces 4 and 4a of the cemented carbide base 3 are filled with various kinds of raw materials having different physical properties depending on the degree of use, and sintered as described above, or in the form of space. Both can be filled with the same raw material or raw materials having different physical properties, and can be sintered as described above.

For example, the upper space portion 4 is filled with diamond powder, and the lower space portion 4a is filled with C.B.N powder and sintered to form cutting edges of various combinations. In addition, the diamond sintered body and the C.B.N sintered body may be formed in a mixture of various spaces on the same upper surface or the lower surface.

The following is described according to the embodiment.

Example 1

Application: Outer diameter machining of tool steel

Synthesis conditions;

Temperature: 1,450 ℃, Pressure: 50,000Pa

Processing condition:

Workpiece: SKD11 (HRc 60 ~ 65)

Cutting Speed: 150m / min

feed rate: 0.10mm / rev

Depth Cut: 0.3mm

Condition: Dry

The C.B.N sintered body obtained under the above conditions was cut into a T8050 shape and cut test resulted in the results as shown in Table 1 below.

In the conventional case compared to the embodiment of the present invention, the cutting conditions are manufactured by cutting into a T8050 shape and welding the adhesive to a rhombus-shaped cemented carbide material at a temperature of 650 to 700 ° C., and then polishing and cutting the cutting condition. It was cut and tested.

Frank Wear (Vb max measurement) Conventional (welding tip) Example (High Temperature, High Pressure Sintering Tip) Elapsed time (min) 3 0.10 0.06 6 0.18 0.15 12 0.30 0.23 15 × 0.35

Example 2

Application: cast iron processing

Synthesis conditions;

Temperature: 1,400 ℃, Pressure: 55,000Pa

Processing condition:

Work material: Gray cast iron GG25 (HB 200 ~ 219)

Cutting Speed: 600m / min

feed rate: 0.20mm / rev

Depth Cut: 0.5mm

Condition: Dry

The C.B.N sintered body obtained under the above conditions was cut into a T8050 shape and cut test resulted in the results as shown in Table 2. The conventional case compared with this is tested on the same conditions as the conventional sample in Example 1.

Frank wear (Vb max measurement) Conventional (welding tip) Example (High Temperature, High Pressure Sintering Tip) Elapsed time (min) 10 0.12 0.11 20 0.52 0.25 30 × 0.60

Example 3

Application: Stone Processing

Synthesis conditions;

Temperature: 1,500 ℃, Pressure: 60,000Pa

Processing condition:

Cutting tip material: diamond sintered medium

Work material: granite (yellow class) Φ150 × 200ℓ

Cuting Speed: 150m / min

feed rate: 0.25mm / rev

Depth Cut: 0.5mm

Condition: Wet

The diamond sintered body obtained under the above conditions was manufactured in the form of a circular cutting tip having a diameter of 13 mm and manufactured by a high temperature and high pressure sintering method and a welding method (conventional). The results are shown in (Table 3).

Frank wear (Vb max measurement) Conventional (welding tip) Example (High Temperature, High Pressure Sintering Tip) Elapsed time (min) 10 0.12 0.11 20 0.52 0.25 30 × 0.60

As described above, in the conventional case, the diamond sintered body or CBN sintered body is peeled off due to thermal stress by adopting the method of joining the diamond sintered body or CBN sintered body prepared separately to the cemented carbide material of the unit piece by welding method, and also the cemented carbide material. In addition, the diamond sintered body or CBN sintered body cutting edges are produced in separate unit pieces, one by one, so that each unit piece has a problem such as having a high manufacturing cost, but the present invention has a diamond for forming a plurality of cutting edges By filling powder or CBN powder into the space of cemented carbide and synthetic sintering under presses of ultra-high temperature and ultra-high pressure, the PCD or PCBN sintered body tip manufactured by the present invention can be compared with the tool tip bonded by conventional welding to the insert insert which is the base material. Too high The bonding strength does not cause a phenomenon of peeling the cutting edge from the cemented carbide material.

In addition, according to the present invention, since several cutting edges are simultaneously obtained on one cemented carbide, an insert having a low manufacturing cost can be obtained by simplifying a process and reducing labor costs by a welding process.

Claims (4)

In an insert having a cutting edge of diamond sintered body or CBN (cubic boron nitride) sintered body in a cemented carbide material, a plurality of circular or semi-circular spaces are secured in the cemented carbide material, so that diamond powder or Filling the CBN powder, and put the powder-filled cemented carbide in a synthetic press and sintered under high temperature and ultra-high pressure to bond the diamond sintered body or CBN sintered body to the cemented carbide to form a plurality of cutting edges at the same time, this is necessary A method for producing an insert for cutting tools, characterized by cutting into insert-shaped pieces of inserts. The method of claim 1, A method of manufacturing an insert for cutting tools, wherein a diamond sintered body or C.B.N sintered body is formed on the upper surface or the upper and lower spaces of the cemented carbide material. The method of claim 2, Diamond sintered body or C.B.N sintered body formed on the upper surface or the upper and lower spaces of the cemented carbide base material is formed by mixing a plurality of spaces with different materials, respectively. The method according to any one of claims 1 to 3, And the high temperature and pressure sintering are performed at 1,300 to 1,600 캜 and 30,000 to 60,000 atmospheres (Pa).