JPS6016395B2 - Cutting blade for cutting tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting blade for a cutting tool that has excellent plowability and heat and wear resistance, and is particularly suitable for use as a cutting blade when cutting difficult-to-cut materials. be.

For cutting difficult-to-cut materials such as high-hardness steel and Ni-based or Co-based superalloys, CBN-based materials containing 80 to 9% by weight of cubic boron nitride (hereinafter referred to as CBN) can be used. A laminated composite grand silk body consisting of a cutting edge layer made of a bonding material and a holding layer made of a tungsten carbide (hereinafter referred to as WC)-based cemented carbide for the purpose of imparting toughness to the cutting edge layer is used as the cutting edge.

However, the cutting edge for the above-mentioned conventional cutting tool usually has a pressure of 5 to 5.
Although it is manufactured under ultra-high pressure coagulation conditions of 6 atmospheric pressure and temperature: 1350 to 1500 qC, abnormally elongated growth of WC grains is observed in the retaining layer, and there are especially pores at the interface between the retaining layer and the cutting edge layer. It was impossible to avoid the formation of

The abnormally elongated grain growth of these WC grains is due to the fact that during ultra-high pressure competitive silking (naturally resulting in liquid phase brazing), a considerable amount of WC is dissolved in the liquid phase (usually composed of Co), while this This is thought to be due to the fact that the precipitation of WC becomes proportionally more active during solidification, and the formation of pores at the interface between both layers is also caused by the formation of CBN, which is the main component constituting the cutting edge layer, during ultra-high pressure sintering.
Because the B inside causes a diffusion reaction with other constituents (such as Co, titanium nitride, and aluminum oxide), nitrogen decomposition occurs easily, and this decomposed nitrogen is not only inside the cutting edge layer but also inside the cutting edge layer. In addition, WC, which also exists at the interface between the cutting edge layer and the holding shoulder and causes pore formation, forms the holding layer.
Since the base cemented carbide is a material with extremely low nitrogen absorption capacity, this is thought to be due to nitrogen remaining particularly at the interface between both layers. If there is abnormal grain growth in the WC grains that make up the retention layer or formation of pores at the interface between both layers,
The interfacial bonding strength between both layers will be significantly reduced, and if the cutting tool blade in this state is used for cutting, the minute vibrations generated during cutting will be amplified, resulting in faster wear of the cutting blade. In addition, chipping and damage were more likely to occur. From the above-mentioned viewpoint, the present inventors have determined that CB constituting the cutting edge layer with respect to cutting edges for cutting tools.
As a result of conducting research to obtain a retaining layer forming material that has high interfacial bonding strength with a CBN-based sintered material containing N: 80 to 9% by weight, and has excellent grade properties and heat and wear resistance, 'a
) The main component of the dispersed phase forming component in the retention layer is composed of titanium carbide (hereinafter referred to as TIC), while the remaining base material is composed of titanium carbide (hereinafter referred to as TIC).
When composed of metallic tungsten (W) having high thermal conductivity and excellent heat resistance strength in a proportion of 0 to 9% by weight, this retaining layer is made of nitrogen decomposed from the CBN constituting the cutting edge layer during ultra-high pressure aging. is easily absorbed and forms titanium carbonitride especially at the interface, so there is no formation of pores, and the retaining layer is solid-phase bonded due to its composition.
It has a fine structure with a theoretical density ratio of 100% and has a microstructure with extremely small grain growth of TIC grains. Therefore, the resulting retaining layer has extremely high interfacial bonding strength to the cutting edge layer, and has high-grade properties and high heat resistance. Because it has high conductivity and high thermoplastic deformability, it exhibits excellent wear resistance and chipping resistance during cutting.

'b- In the above retaining layer, T is used as a dispersed phase forming component.
In addition to IC, one or more carbides of umbrella, soft, and candy group metals in the periodic table excluding Ti (hereinafter collectively referred to as metal carbides) may be used alone or in combination with TIC. When either or both of the solid solutions are contained, not only the grain growth of TIC during competitive bonding is further suppressed, but also the hardness and rutting properties of TIC itself are improved, and the binding phase and The bonding strength of the parts will also be further improved. The findings shown in 'a} and 'b} have been obtained above.

This invention was made based on the above knowledge, and the cutting edge for a cutting tool is made of a cutting edge layer made of a CBN-based scale-stripe material containing 80 to 90% by weight of CBN, and a cutting edge layer made of a CBN-based scale-stripe material containing 80 to 90% by weight of CBN. It is composed of a laminated composite body with a holding layer of a TIC-based carbide-dispersed W-based sintered alloy whose matrix is W, and the TIC-based carbide is {11 TIC, ■ TIC
and one or more metal carbides, '3'T
A composite solid solution of IC and one or more metal carbides, ■ TIC and one or more metal carbides, and TIC and one or more metal carbides. The composite solid solution is characterized by being composed of any one of the above [1-'41].

In addition, in the case where the W content in the holding layer of the cutting edge for a cutting tool of the present invention is limited to 50 to 9% by weight, if the content is less than 5% by weight, the content of carbides will be relatively large. If the content exceeds 9% by weight, the content of carbides becomes relatively too small and it is difficult to ensure the desired heat resistance strength and nitrogen absorption effect. This is because it is not possible.

Next, the cutting blade for a cutting tool according to the present invention will be specifically explained with reference to Examples.

Example 1 TI with an average particle size of 1.5 mm was placed in a thin cylindrical container made of Zr.
A homogeneous mixed powder consisting of 4% by weight of C powder and 60% by weight of W powder of 0.6mm was charged, and then 200% of the average particle size was added on top of it. An average mixed powder consisting of 〃m of CBN powder: 9% by weight and 1.2m of TaN powder: 1% by weight was charged and filled, and then the entire container filled with the mixed powder was charged. was charged into a normal ultra-high pressure and ultra-high temperature generator, pressure: 5 melons, temperature: 1400q.
After being held under the conditions of 1
The shape shown in schematic perspective view in the figure, i.e. the planar shape:
Center angle 90o and radius 3. The fan shape of the cape, the thickness of the cutting edge layer la: 0.5 sail, the thickness of the retaining layer lb: 2. A cutting blade 1 for a cutting tool of the present invention having a rib (overall thickness: 2.5 ribs) was manufactured.

When the resulting cutting edge 1 for a cutting tool of the present invention was polished with a diamond wheel and its structure was observed, both the upper cutting edge layer la and the lower retaining layer lb showed a theoretical density ratio of 100%. It was something.

Further, the cross section exhibited an irregular surface, and no pores were observed in the interior as well as at the interface between the two layers, confirming that the two layers were firmly adhered to each other. Furthermore, the above-mentioned retaining layer exhibited a Vickers hardness of 1400k9/Iso. On the other hand, for comparison purposes, the retention layer was
A cutting blade 1' for a conventional cutting tool was manufactured under the same manufacturing conditions as the cutting blade 1 for a cutting tool of the present invention, except that it was made of a cemented carbide having a composition of 6% Co by weight. As shown in the plan view in Fig. 2 and the front view in Fig. 3, the cutting blades for both cutting tools have planar dimensions: 12.7 holes,
Thickness: 4.8 mm WC-based cemented carbide cutting tip (throw-away tip) 2 is attached to the cutting edge of the first floor of the four corners by brazing, and then attached to the cutting tool, and then Cutting material: Carburized and quenched steel (〇Cwell hardness HRC:
62), cutting speed: 100 m/min, feed: 0.1 rib/rev. , depth of cut: 1. A cutting test was conducted under conditions of a mountain surface, and the cutting time until the flank wear reached 0.3 skin was measured. As a result, the cutting tip using the cutting blade for the cutting tool of the present invention reached the end of its life due to normal wear after 118 minutes, whereas the cutting tip using the cutting blade for the conventional cutting tool suffered from chipping and reached the end of its life after 118 minutes. It lasted until the end of its lifespan.

Example 2 The same procedure as in Example 1 in which the cutting blade 1 for a cutting tool of the present invention was manufactured, except that the mixing ratio of the mixed powder for forming the cutting edge layer and the retaining layer was as shown in Table 1. Under the following conditions, cutting blades a to n for cutting tools of the present invention and cutting blades a and b for conventional cutting tools having substantially the same final component composition as the blended composition were manufactured, respectively.

When the structures of the interface portion between the cutting edge layer and the retaining layer of the cutting edges a to n for the cutting tool of the present invention and the cutting edges a and b for the conventional cutting tool obtained as a result were observed, it was found that the cutting edge for the cutting tool of the present invention a~n
In both cases, no pores are observed at all, and the structure is fine and uniform.However, in conventional cutting tool cutting edges a and b, pores are present at the interface between both layers. observed.

Table 1 also shows the Vickers hardness of the retention layer. Next, each of the cutting edges a to n for the cutting tool of the present invention and the cutting edges a and b for the conventional cutting tool were attached to a cutting tip in a divided state in the same manner as in Table 1 of Example 1, and further attached to a cutting tool. , Work material: Inconel 718
Cutting speed: 120m/min, feed: 0.15 side/re
v. , depth of cut: 1. A cutting test was carried out under the following conditions: flank abrasion, side edge angle: 450, cutting oil: water-based cutting fluid, and the cutting time until flank wear reached the 0.3 side was measured.

The measurement results are shown in Table 2. Table 2 also shows the state of the cutting edge. As shown in Table 2, the cutting edges a to n for cutting tools of the present invention all show normal wear, so it can be easily understood that the bonding strength between the cutting edge layer and the retaining layer is extremely high. It is clear that the cutting life is much better than that of the composite composite piece, which suffers from chibbing during cutting due to the low interfacial bonding strength of both layers.

In addition, in the above embodiment, a case was described in which the cutting blade for a cutting tool is used in a divided state and attached to the cutting edge portion of a cutting tip made of cemented carbide, but the cutting blade for a cutting tool may be used without being divided or Of course, Table 2 may be used even if the tip is made into a large size and appropriately shaped and used as a cutting tip as it is.

As described above, the cutting edge for a cutting tool of the present invention has excellent toughness and heat and wear resistance by forming the retaining layer from a tungsten-based alloy containing TIC, and has excellent toughness and heat and wear resistance. Since the bonding strength is also extremely high, it has industrially useful properties, such as being able to further extend the cutting life, especially when cutting hammered materials.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a cutting blade for a cutting tool;
FIG. 2 is a plan view showing the state in which the cutting blade for the cutting tool is attached to the cutting edge portion of the cutting tip, and FIG. 3 is a front view of the same. In the drawings, 1, 1'... Cutting blade for cutting tool, la...
Cutting edge layer, lb...holding layer, 2...cutting tip. Chong' Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A cutting edge layer of a cubic boron nitride-based sintered material containing 80 to 90% by weight of cubic boron nitride, and a carbide whose base material accounts for 50 to 90% by weight of metallic tungsten. A cutting blade for a cutting tool characterized by being made of a laminated composite sintered body including a holding layer of a titanium-based carbide-dispersed tungsten-based sintered alloy. 2. The cutting blade for a cutting tool according to claim 1, wherein the carbide mainly composed of titanium carbide is made of titanium carbide. 3 The carbide mainly composed of titanium carbide is composed of titanium carbide and T
The cutting edge for a cutting tool according to claim 1, characterized in that it is made of one or more carbides of metals of groups 4a, 5a, and 6a of the periodic table, excluding metals i. 4 The carbide mainly composed of titanium carbide is composed of titanium carbide and T
The cutting tool according to claim 1, characterized in that it is made of a composite solid-liquid with one or more carbides of metals of groups 4a, 5a, and 6a of the periodic table excluding i. Cutting blade for use. 5. The above titanium carbide-based carbide is composed of titanium carbide, one or more carbides of metals in groups 4a, 5a, and 6a of the periodic table excluding Ti, and a solid-liquid composite thereof. A cutting blade for a cutting tool according to claim 1.