JPH09108910A - Composite cutting tip whose cutting edge piece has excellent joining strength - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite cutting tip whose cutting edge piece is brazed to a cutting edge part of a tip main body with high joining strength. SOLUTION: A composite cutting tip contains Ti: 0.5 to 10% and/or Zr: 0.5 to 10% and Cr: 5 to 20 % in weight% in a cutting edge part of a WC group cemented carbide-made tip main body, and also contains one or more kinds: 2 to 10% among P, B and Si according to it necessity, and a residual part is composed of a material by joining a diamond group sintered material-made cutting edge piece by brazing by using an Ni alloy brazing material having the composition composed of Ni and unavoidable impurity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high joining strength of a diamond-based sintered material cutting edge piece to a cutting edge portion of a tungsten carbide (hereinafter referred to as WC) -based cemented carbide chip body, and therefore high-speed cutting. The present invention also relates to a composite cutting tip which exhibits excellent cutting performance over a long period of time without peeling of the cutting edge piece even when used for.

[0002]

2. Description of the Related Art Conventionally, as one of composite cutting tips, as shown in a schematic perspective view in FIG. 1, a cutting edge portion of a WC-based cemented carbide chip body 1 is made of Ag-10 to 30 wt% Cu. There is known a structure in which a cutting edge piece 3 made of a diamond-based sintered material is brazed and joined through a brazing material 2 of an Ag alloy having a composition, which is a non-ferrous material such as a Ti alloy or an aluminum oxide-based ceramics. It is also known to be used for cutting non-metallic materials such as. It is also known that the chip body is manufactured by an ordinary powder metallurgy method, and the cutting blade piece is also manufactured by using an ordinary ultra-high pressure sintering apparatus.

[0003]

On the other hand, in recent years, cutting machines have been remarkably improved in performance, and there is a strong demand for labor saving in cutting. Accordingly, cutting tends to be speeded up. , In the above conventional composite cutting tip,
When this is used for high-speed cutting, since the joining strength of the cutting edge piece to the cutting edge portion of the chip body is insufficient, peeling easily occurs, and it is the current situation that the service life reaches a relatively short time. .

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoint, focusing on the conventional composite cutting tip, in order to improve the bonding strength between the tip body and the cutting blade piece constituting the same, as a result of research on the brazing material used for this, In the brazing joining of the chip body and the cutting blade piece, in% by weight (hereinafter,% indicates% by weight),
Ti: 0.5-10% and / or Zr: 0.5-1
0%, Cr: 5 to 20%, and, if necessary, one or more of P, B, and Si:
When a Ni alloy brazing material containing 2 to 10% and the balance of Ni and unavoidable impurities is used, the resulting composite cutting tip is peeled off to the above cutting edge piece even when it is used for high speed cutting. The result of the research was that there was no occurrence of cutting edge, and excellent cutting performance was exhibited over a long period of time.

The present invention has been made based on the above-mentioned research results, and a cutting edge piece made of a diamond-based sintered material is attached to a cutting edge portion of a WC-based cemented carbide chip body through a brazing material. In a composite cutting tip that is brazed and joined,
The above brazing material is Ti: 0.5 to 10% and / or Z
r: 0.5 to 10%, Cr: 5 to 20%, and, if necessary, one or more of P, B, and Si: 2 to 10%. The present invention is characterized by a composite cutting tip in which the remainder is made of a Ni alloy having a composition of Ni and inevitable impurities to enhance the bonding strength of the cutting edge piece to the tip body.

Next, the reason why the component composition of the Ni alloy brazing material constituting the composite cutting tip of the present invention is limited as described above will be explained. (A) Ti and Zr These components have the effect of further improving the wettability of the brazing material with respect to the chip body and the cutting edge piece, thereby improving the bonding strength, but their contents are each less than 0.5%. However, the desired effect cannot be obtained in the above-mentioned action, and on the other hand, if the content of each exceeds 10%, the strength of the brazed portion will be reduced, so that the content of each of the content is 0.5-0.5%.
It was set to 10%, preferably 5 to 7%.

(B) Cr The Cr component has the effect of improving the hardness of the brazing material, but if the content of Cr is less than 5%, the desired hardness-improving effect cannot be obtained, while the content of Cr is 20. %, The rollability will rapidly decrease, so the content should be 5 to 2
It was set to 0%, preferably 10 to 15%.

(C) P, B, and Si These components have the effect of lowering the melting point of the brazing material, thereby increasing the fluidity, and enabling brazing joining with a smaller amount of brazing material. Therefore, if the content is less than 2%, the desired effect on the above action cannot be obtained. On the other hand, if the content exceeds 10%, the strength of the brazed part decreases. Therefore, the content is defined as 2 to 10%, preferably 3 to 8%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION First, as a raw material powder, diamond powder having an average particle diameter of 5 μm and MgCO ₃ having an average particle diameter of 5 μm are used.
Using powders, these raw material powders were mixed in a predetermined ratio, mixed in a ball mill for 72 hours, and then pressed into a green compact at a pressure of 1 ton / cm ² , and this green compact was subjected to ordinary belt-type ultra high pressure firing. Charge into the binding device, pressure: 8 GPa and temperature: 2
200 ° C. pressure and temperature by sintering under the conditions of holding 30 minutes diameter: 8 mm ^phi × thickness: has a dimension of 1.5 mm, and the diamond-based sintered material made having a composition of diamond -7% MgO A cutting blade piece was manufactured by forming a cutting blade material and processing it into an equilateral triangle having a side length of 5 mm with an ultrasonic cutter to a thickness of 1.4 mm.

As the raw material powder, the average particle diameter is 5 μm.
And WC powder having the same content: 3 μm of Co powder, these raw material powders were blended in a predetermined blending composition, wet-mixed in a ball mill for 72 hours, dried, and then dried at 1 ton / cm ^2.
Press forming into a green compact with pressure of 1 x 1
Sintered in a vacuum of 0 ^-3 torr at 1450 ° C for 1 hour and sintered to have a composition of WC-8% Co and a shape of TPGN332 (thickness: an equilateral triangle with a side length of 16 mm and 3.18 mm). By forming a WC-based cemented carbide chip body material with the following, and forming a regular triangular counterbore with a side length of 5 mm with a depth of 1.4 mm at the cutting edge that occupies one corner of this, the chip body is formed. Manufactured.

Furthermore, a Ni alloy molten metal and an Ag alloy molten metal having the component compositions shown in Tables 1 and 2 were prepared by a usual melting method, and each was cast into an ingot under normal conditions and hot-melted. Ni alloy brazing filler metal for composite cutting tip of the present invention (hereinafter referred to as brazing filler metal of the present invention) a to w having a thickness of 0.35 mm after being subjected to rolling and cold rolling, and conventional composite cutting tip A
A g-alloy brazing material (hereinafter referred to as a conventional brazing material) was manufactured.

Next, the cutting blade pieces are set on the chip body through the brazing filler metals a to w of the present invention and the conventional brazing filler metal, and this is set to 1 kg / cm ² by using a hot press.
After pressurizing at a pressure of 1 × 10 ⁻³ torr in a vacuum of 125
The present invention composite cutting tips (hereinafter referred to as the present invention chips) 1 to 23, and the conventional composite cutting tips (hereinafter referred to as the following) by brazing and joining at 0 to 1350 ° C. for 5 minutes.
Conventional chips) were manufactured respectively.

Next, for each of the various chips obtained as a result, a work material: a Ti alloy round bar having a composition of Ti-6% Al-4% V, a cutting speed: 500 m / min., And a cut: 0 0.25 mm, feed: 0.1 mm / rev., Cutting time: 2.5 minutes, a dry continuous high-speed cutting test of steel was performed, and the flank wear width of the cutting edge piece was measured. The measurement results are shown in Table 3.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

From the results shown in Table 3, all of the chips 1 to 23 of the present invention have extremely high bonding strength to the chip body of the cutting blade, so that the cutting blade can be used for high-speed cutting of Ti alloy, which is a difficult-to-cut material. It is clear that the chip has excellent cutting performance without delamination, whereas the conventional chip has delamination on the cutting edge in a relatively short time after the start of cutting, and thus reaches the end of its service life. As described above, the composite cutting tip of the present invention has extremely high bonding strength to the tip body of the cutting edge piece, so that the cutting edge piece does not peel off even when used for high-speed cutting, and therefore the cutting speed is increased and It is possible to deal with labor saving sufficiently and satisfactorily.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a composite cutting tip.

[Explanation of symbols]

 1 Chip body 2 Brazing material 3 Cutting edge piece

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C04B 35/52 301 C04B 35/52 301B 37/00 37/00 B C22C 19/03 C22C 19/03 G 29/08 29/08

Claims (2)

[Claims] 1. A composite cutting tip comprising a cutting edge portion of a tungsten carbide based cemented carbide tip body brazed to a cutting edge portion of a diamond based sintering material via a brazing material, wherein the brazing material is used. %, Ti: 0.5-10% and / or Zr: 0.5-1
A composite cutting tip having excellent bonding strength with a cutting edge piece, characterized in that it is made of a Ni alloy containing 0%, Cr: 5 to 20%, and the balance being Ni and inevitable impurities. 2. A composite cutting tip obtained by brazing a cutting edge portion made of a diamond-based sintered material to a cutting edge portion of a tungsten carbide-based cemented carbide chip body with a brazing material interposed therebetween. %, Ti: 0.5-10% and / or Zr: 0.5-1
0%, Cr: 5 to 20%, and one or more of P, B, and Si: 2 to
A composite cutting tip having excellent bonding strength with a cutting edge piece, characterized in that it is made of a Ni alloy containing 10% and the balance being Ni and inevitable impurities.