JPH05116006A - Carbon-nitride titanium group cermet cutting tool excellent in heat resistant plastic deformability - Google Patents

Abstract

(57) [Abstract] [Purpose] To develop a cutting tool made of TiCN-based cermet that exhibits excellent heat plastic deformation properties in cutting under severe conditions with heat generation. A cutting tool, in wt%, one or two of Co and Ni as a binder phase forming component: 0.2 to
8%, ZrO ₂ as a dispersed phase forming component and stabilized Z
One or two kinds of rO ₂ : 5 to 30%, ZrCN as a disperse phase forming component: 1 to 44%, and the balance is 50% or more of TiCN as a disperse phase forming component and inevitable impurities. And a TiCN-based cermet having the following composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent resistance to thermal plastic deformation, and therefore does not undergo thermal deformation even during cutting under severe conditions with high heat generation, and has excellent long-term resistance. The present invention relates to a titanium oxynitride (hereinafter referred to as TiCN) -based cermet cutting tool that exhibits wear resistance.

[0002]

2. Description of the Related Art Conventionally, for cutting steel or ductile cast iron, for example, as described in Japanese Patent Laid-Open No. 52-94814, Ni is a main component in% by weight (hereinafter,% indicates% by weight). It is well known that a TiCN-based cermet cutting tool composed of a TiCN-based cermet having a composition of a binder phase of 10 to 49% and a dispersed phase of TiCN: the rest is used.

[0003]

On the other hand, in recent years, demands for labor saving and speeding up of cutting work are severe, and accordingly, high speed cutting and heavy cutting such as high feed and high depth of cut are inevitable. Since cutting under extremely severe conditions is accompanied by extremely high heat generation, it is necessary for the cutting tool to have excellent heat plastic deformation, but the above-mentioned conventional TiCN-based cermet cutting Tools, and many other TiCN-based cermet cutting tools,
At present, all of them are liable to be thermally deformed due to the relatively high content ratio of the binder phase, and cannot satisfy these requirements sufficiently.

[0004]

Therefore, the present inventors have
From the above viewpoints, as a result of conducting research to develop a cutting tool made of TiCN-based cermet which exhibits excellent heat plastic deformation property even for cutting under severe conditions, as a result, (a) the above conventional cutting tool is constituted. In the TiCN-based cermet, the content of the binder phase is 10 to 10.
If 49% is reduced to 8% or less, the heat plastic deformation property is improved, but with such a low content of the binder phase, good sinterability cannot be ensured and the strength is reduced. Remarkable thing.

(B) However, in a TiCN-based cermet cutting tool, the TiCN-based cermet constituting the cutting tool contains either 5% to 30% of zirconia (hereinafter referred to as ZrO ₂ ) or stabilized ZrO ₂ . If contained in a ratio, even if the binder phase content is 8% or less, excellent sinterability is exhibited, so that sufficient strength can be secured, and further zirconium carbonitride (hereinafter referred to as ZrCN).
When ZrCN is contained in a proportion of 1 to 44%, it has excellent thermal conductivity due to the action of ZrCN, and as a result, it is possible to reduce the binder phase content to 8% or less. It becomes deformable, and exhibits excellent wear resistance for a long period of time without being thermally deformed even when cutting under severe conditions that generate high heat as a cutting tool. The research results shown in (a) and (b) above were obtained.

The present invention has been made based on the above-mentioned research results, and one or two kinds of Co and Ni as binder phase forming components: 0.2 to 8%, dispersed phase forming component Or 2 kinds of ZrO ₂ as a stabilizer and stabilized ZrO ₂ : 5 to 30%, ZrCN as a dispersed phase forming component: 1 to 44%, and the remaining 50% as a dispersed phase forming component The cutting tool made of TiCN-based cermet, which is composed of the TiCN-based cermet having the composition of TiCN and unavoidable impurities, is characterized.

Next, the reason why the component composition of the TiCN-based cermet constituting the cutting tool of the present invention is limited as described above will be explained. (A) Co and Ni These components have the effects of improving sinterability and forming a binder phase after sintering to improve strength, but if the content is less than 0.2%, The desired effect is not obtained on the other hand, and if the content exceeds 8%, the heat-resistant plastic deformability will decrease, so the content should be 0.2-8.
Defined as%.

[0008] (b) ZrO ₂ and ZrO ₂ which stabilized ZrO ₂ referred to here means pure ZrO _2, also stabilized ZrO ₂ is, Y, Ca, Mg, and one of the oxides of rare earth elements Zr in which the above is dissolved in a proportion of 1 to 10%
It means O ₂ , and these components have the effect of remarkably improving the sinterability as described above. Therefore, even if the content of the binder phase is reduced to 8% or less, excellent sinterability is obtained. Since it can be ensured, sufficient strength can be obtained, and the heat-resistant plastic deformability of the cutting tool can be improved by reducing the content of the binder phase, but if the content is less than 5%, the above-mentioned action is desired. The improvement effect cannot be obtained, and on the other hand, if the content exceeds 30%, the wear resistance will decrease, so the content was set to 5 to 30%.

(C) ZrCN The ZrCN component has a function of further improving the thermal conductivity, whereby the heat generated by cutting is quickly released, and the thermal deformation of the cutting tool is suppressed. However, if the content is less than 1%, the desired effect cannot be obtained, and if the content exceeds 44%, the wear resistance decreases, so that the content should be 1 to 44%. Defined as%.

(D) TiCN TiCN is extremely hard, and therefore, if the content of TiCN is less than 50%, the desired excellent wear resistance cannot be ensured. Therefore, the content thereof is defined as 50% or more.

Ti constituting the cutting tool of the present invention
In the CN-based cermet, the C / N atomic ratio of TiCN and ZrCN, which are the constituents, is preferably 2/8 to 8/2.

[0012]

EXAMPLES Next, the cutting tool of the present invention will be specifically described by way of examples. As raw material powder, 0.5-
Various TiCx with average particle size in the range of 1.5 μm
Ny and ZrCxNy powder, ZrO ₂ powder, Y
₂ O ₃ : 3% solid solution stabilized ZrO ₂ powder, CaO: 8%
Solid solution stabilized ZrO ₂ powder, MgO: 10% solid solution stabilized ZrO ₂ powder, CeO ₂ : 10% solid solution stabilized ZrO
₂ powders, La ₂ O ₃ : 10% solid solution stabilized ZrO ₂ powder, Co powder, and Ni powder, Mo powder, and carbon powder were prepared, and these raw material powders were blended to the blending composition shown in Table 1. After wet-mixing for 72 hours in a ball mill and drying, the green compact is press-molded at a pressure of 1 ton / cm ² , and the green compact is heated to a predetermined temperature within a range of 1400 to 1600 ° C. in a nitrogen atmosphere. Sintering chips of SNGN120408, which have substantially the same composition as the compounded composition, are obtained by normally sintering under the condition of holding for a time, and subsequently by HIPing under the conditions of pressure: 1500 atm and temperature: 1400 ° C. The present invention TiCN-based cermet cutting tool (hereinafter referred to as the present invention cutting tool) 1 to 8 and the conventional TiCN-based cermet cutting tool (hereinafter referred to as the conventional cutting tool) 1 to 3 having a shape Re respectively were produced.

[0013]

[Table 1]

Next, regarding the various cutting tools obtained as a result, the work material: SCM440, cutting speed: 340 m / min, feed: 0.3 mm / rev., Depth of cut: 1.5 mm, cutting time: 20 min, The wet high speed continuous cutting test of steel was carried out under the conditions described above, and the flank wear width of the cutting edge was measured. These results are shown in Table 1 together with the anti-segregation force measured for the purpose of evaluating strength.

[0015]

From the results shown in Table 1, the cutting tools 1 to 8 of the present invention have ZrO ₂ and ZrO _{2 in} spite of the relatively low content of the binder phase in the TiCN-based cermet constituting them. By the action of the stabilized ZrO ₂ , excellent sinterability is ensured, so that it has the same strength as the conventional cutting tools 1 to 3 in which the content of the binder phase is relatively high, and the binder phase is Due to the action of ZrCN, which has a low content and has the effect of improving thermal conductivity, it has excellent heat-resistant plastic deformability, so it exhibits excellent wear resistance even in high-speed cutting accompanied by high temperature generation. In contrast, conventional cutting tools 1-
It is clear that No. 3 is plastically deformed immediately after the start of cutting due to the high content of the binder phase, resulting in uncutability.

As described above, since the TiCN-based cermet cutting tool of the present invention has excellent heat-resistant plastic deformability, it is particularly suitable for cutting under severe conditions such as high-speed cutting or heavy cutting accompanied by heat generation. It exhibits excellent wear resistance and exhibits excellent cutting performance over a long period of time.

[Procedure amendment]

[Submission date] April 3, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

EXAMPLES Next, the cutting tool of the present invention will be specifically described by way of examples. As raw material powder, 0.5-
Various TiCx with average particle size in the range of 1.5 μm
Ny and ZrCxNy powder, ZrO ₂ powder, Y
₂ O ₃ : 3% solid solution stabilized ZrO ₂ powder, CaO: 8%
Solid solution stabilized ZrO ₂ powder, MgO: 10% solid solution stabilized ZrO ₂ powder, CeO ₂ : 10% solid solution stabilized ZrO
₂ powders, La ₂ O ₃ : 10% solid solution stabilized ZrO ₂ powder, Co powder, Ni powder, Mo powder, and carbon powder are prepared, and these raw material powders are used as cutting tools 1 to 1 of the present invention.
3, 5, 7, and 8 and conventional cutting tools 1-3
In addition, it was added to the mixing composition shown in Table 1 and mixed with a mixing ball.
And using a sintered ZrO ₂ ball with a particle size of 1 mm
Wet-mix for 72 hours in a mill.
For 6 and 6, Co powder and Ni were used as raw material powders.
Instead of powder, instead of this, particle size: 1 mm
Composition with: TiC _0.5 N _0.5 -30% Co and Ti
With ceramic balls of C _0.5 N _0.5 -40% Ni,
The wet mixing time in the ball mill is related to the cutting tool 4 of the present invention.
60 hours, 12 hours for the cutting tool 6 of the present invention
Due to wear during mixing of the ceramic balls
And Ni to supply the compounding composition shown in Table 1,
After the deviation is also dried, the green compact is press-molded with a pressure of 1 ton / cm ² , and the green compact is placed in a nitrogen atmosphere at 1400 to 160
Normally sintered at a predetermined temperature within the range of 0 ° C. for 1 hour, and then pressure: 1500 atm, temperature: 140
By HIPing at 0 ° C., the composition of the composition is substantially the same as that of the composition, and SNGN120408
Cutting tool made of TiCN-based cermet of the present invention having a throw-away tip shape (hereinafter referred to as the cutting tool of the present invention)
1 to 8 and conventional TiCN-based cermet cutting tools (hereinafter referred to as conventional cutting tools) 1 to 3 were manufactured.
In the case of the above embodiment, Co powder and
CoO powder in the coexistence with carbon powder in addition to Ni powder and Ni powder.
Powder, NiO powder, Co ₃ Ti powder and Ni ₃ T
By using i powder, the decomposition reaction during sintering of these powders
Bonding phase by generating a predetermined amount of Co and / or Ni
May be formed.

Claims (1)

[Claims] 1. By weight, one or two of Co and Ni as binder phase forming component: 0.2-8%, one of zirconia and stabilized zirconia as disperse phase forming component. Or 2 kinds: 5 to 30%, zirconium carbonitride as a dispersed phase forming component: 1 to 44
%, And the remainder is composed of a titanium carbonitride-based cermet having a composition of 50% or more of titanium carbonitride as a dispersed phase forming component and unavoidable impurities, which is excellent in heat plastic deformation characteristics. Cutting tool made of titanium nitride based cermet.