JPS6151034B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a surface-coated cermet member which has excellent impact resistance and is particularly suitable for use as a cutting tool for high-speed cutting of steel. Conventionally, as hard phase forming components, Ti, W,
4a, 5a, and 6a of the periodic table of elements excluding Ti and W
Composite metal carbonitride solid solution with one or more group metals (hereinafter referred to as (Ti, M, W) CN): Contains 60 to 90%, and if necessary,
Mo as a bonding phase forming component: 1 to 20%, W: 1
~20%, and Al: 0.1 to 2%, for the purpose of improving heat resistance, and the remainder consists of one or two of Ni and Co and unavoidable impurities. On the surface of a cermet member with (the above weight %, below % shows weight %)
Carbides, nitrides, carbonitrides, carbonates, and carbonitrides of Ti, and oxides of Al (hereinafter, these are referred to as TiC, TiN, TiCN, TiCO,
A surface coating layer consisting of a single layer or a multilayer of two or more of TiCNO, and Al ₂ O ₃ ).
Surface-coated cermet members formed with an average layer thickness of 0.5 to 10 μm are used as cutting tools. However, this conventional surface-coated cermet member
For example, when used for high-speed cutting of steel at a cutting speed exceeding 250 m/min, the cutting edge tends to chip due to insufficient impact resistance, resulting in an extremely short tool life. On the other hand, in recent years, there has been a strong demand for improved machining efficiency, and the current situation is that there is a strong desire to develop cutting tools capable of high-speed cutting at a cutting speed of 250 to 300 m/min. Therefore, from the above-mentioned viewpoint, the present inventors
In order to develop cutting tools that can withstand high-speed cutting at cutting speeds of 250 m/min or higher, we conducted research focusing on the conventional surface-coated cermet parts mentioned above, and found that the relationship between the surface of the cermet parts and the surface coating layer When a layer consisting of a binder phase forming component of the cermet member diffused in the TiC coating layer is interposed as an intermediate layer between the two, this intermediate layer has excellent resistance due to the diffused binder phase forming component. It has impact resistance and bonds with extremely high adhesion strength to both the surface of the cermet component and the surface coating layer, so it will not chip on the cutting edge during high-speed cutting at cutting speeds of 250 m/min or more. We have obtained the knowledge that this method does not cause such problems and exhibits excellent cutting performance. Therefore, this invention was made based on the above knowledge, and includes (Ti, M, W) CN:60 as a hard phase forming component.
~95%, and if necessary, as a binder phase forming component, Mo: 1~20%, W:
1 to 20%, and one or two of Al: 0.1 to 2%, and the remainder consists of one or two of Ni and Co as bonding phase forming components and unavoidable impurities. TiN, TiCN, TiCO, TiCNO, and Al are applied to the surface of a cermet member having a composition of A surface-coated cermet member for a cutting tool is characterized by forming a surface coating layer consisting of a single layer or a multilayer of two or more of ₂ O ₃ with an average layer thickness of 0.5 to 10 μm. be. Next, in the surface-coated cermet member of the present invention, the reason why the component composition of the cermet member and the average layer thickness of the intermediate layer and the surface coating layer are limited as described above will be explained. A Composition of cermet members (a) (Ti, M, W) CN These components have the effect of forming a skeleton, improving the hardness of the cermet member itself, and improving its plastic deformation resistance. If the content is less than 60%, the desired effect cannot be obtained, while if the content is 95%, the toughness of the cermet member will deteriorate. Established. (b) Mo, W, and Al These components have the effect of solid solution or precipitation in the binder phase to strengthen it and improve heat resistance, so when these properties are required. is contained as necessary, but if the content is less than 1% for Mo, less than 1% for W, and less than 0.1% for Al, the desired effect cannot be obtained;
If the content exceeds Mo: 20%, W: 20%, and Al: 2%, the wear resistance will decrease, so the contents should be adjusted to Mo: 1 to 20% and W: 1 to 20%, and Al: 0.1 to 2%. B Average layer thickness of the intermediate layer TiC constituting the intermediate layer is the only component that firmly bonds with the cermet member surface and the surface coating layer and allows the diffusion and inclusion of the binder phase forming component. If the average layer thickness is less than 0.5 μm, it is not possible to secure the desired excellent impact resistance, while if the average layer thickness exceeds 10 μm, it is difficult to substantially diffuse the binder phase-forming component throughout the layer thickness. Coupled with this, the average layer thickness was determined to be 0.5 to 10 .mu.m since the overall impact resistance of the surface-coated cermet member would be degraded. C Average layer thickness of surface coating layer The formation of these surface coating layers significantly improves wear resistance, but if the average layer thickness is less than 0.5 μm, the desired wear resistance cannot be secured. On the other hand, if the average layer thickness exceeds 10 .mu.m, the impact resistance of the surface-coated cermet member itself will decrease due to the surface coating layer, so the average layer thickness was set at 0.5 to 10 .mu.m. Next, the surface-coated cermet member of the present invention will be specifically explained using examples. Examples All of the raw material powders had an average particle size within the range of 1.0 to 2.0 μm, and were completely dissolved in solid solution. (Ti _{0 , 45} Ta ₀ , ₀₅ W _0.50 ) _{C 0.80} N _0.20 powder _{( Ti 0.50 Nb 0.20 Mo 0.10 W 0.20 ) C 0.70} N _{0.30 powder} , ( _{Ti 0.60 Ta 0.10 Mo 0.10 W 0.20) C 0.65 N 0.35 powder , ( Ti 0.65 Ta 0.10} Cr _{0.10 W 0.15} ) _{C 0 . 60} N _0.40 powder _, (Ti _{0.70 Nb 0.10 W 0.20 ) C 0.50 N 0.50} powder, ( _{Ti 0.80 V 0.10 W 0.10 ) C 0.40} N _{0.60 powder ,} ( _{Ti 0.60 Zr 0.05 Ta 0.15 W 0.20 ) C 0.70} N _0.30 powder _, ( _{Ti 0.60 Hf 0.05} Ta _{0.15 W 0.20 ) C0.75 N0.25 powder , ( Ti0.65 V0.05 Ta0.10 W0.20 ) C0.75 N0.25 powder , ( Ti0.60 Cr0.05 W0 _ _ .35 ) C0.70 N0.30 powder , ( Ti0.60 Zr0.05 W0.35 ) C0.70 N0.30 powder , ( Ti0.55 Hf0.05 Ta0.10 _ _} Mo _0.05 W _0.25 ) C _0.65 N _0.35 powder, (values in brackets above _are weight ratios) _{, and} each has an average particle size within the range of 0.6 to 2.5 μm _.
Mo powder, W powder, Al powder, Ni powder, and Co powder were prepared, and these raw material powders were blended into the composition shown in Table 1, wet milled and mixed in a ball mill for 72 hours, and then dried. , press-formed at a pressure of 15 kg/cm ² to form a green compact, and then baked the green compact at a predetermined temperature within the range of 1410 to 1480°C for 1 hour in an N ₂ atmosphere. As a result, cermet members having substantially the same composition as the blended composition are manufactured, and subsequently, these cermet members are charged into a reaction vessel made of a heat-resistant alloy,

【table】

[Table] At a temperature of 1000℃, TiCl ₄ : 2%, CH ₄ : 2%,
A reaction mixture gas having a composition (volume %) consisting of H ₂ :remaining was fed at a flow rate of 10/min to react, and the reaction time was varied to form a TiC layer with the average layer thickness shown in Table 1. It is formed on the surface of the cermet member, and after the reaction is completed, residual gas is removed and 1050
The binder phase forming component in the cermet member is diffused into the TiC layer by heating at a temperature of 100°C for 1 hour to form an intermediate layer. After heating to a temperature of °C, a reaction mixture gas having a gas composition shown in Table 2 is introduced depending on the composition of the surface coating layer to be formed, and heated to the reaction temperature also shown in Table 2. Surface-coated cermet members 1 to 20 of the present invention and Comparative surface-coated cermet members 1 were prepared by holding and forming surface coating layers having the composition, average layer thickness, and number of layers shown in Table 1, respectively.
-6 were produced, respectively. In addition, the comparative surface-coated cermet members 1 to 6 have different compositions of the cermet members,
Which of the intermediate layer and surface coating layer

[Table] Items marked with * in Table 1 are outside the scope of this invention. Next, using these surface-coated cermet members, workpiece material: JIS/SNCM-8 (hardness H _B 240) round bar, cutting speed: 300 m/min, feed: 0.3 mm/rev., depth of cut: 1.5 mm, Cutting time: 10 min, Chip shape: JIS/SNP432, Steel continuous high-speed cutting test under the following conditions, Work material: JIS/SNCM-8 (Hardness _HB 240) square material, Cutting speed: 250 m/ A steel interrupted cutting test was conducted under the following conditions: min, feed: 0.2mm/rev., depth of cut: 2mm, cutting time: 3min, chip shape: JIS/SNP432, and in the former high-speed cutting, the flank wear width of the cutting edge and Measure the rake face wear depth and also perform 10 tests in the latter interrupted cut.

【table】

[Table] The number of broken cutting edges was measured. The results of these cutting tests are shown in Table 3. From the results shown in Table 3, surface-coated cermet members 1 to 20 of the present invention all have excellent plastic deformation resistance, impact resistance, and wear resistance, so they are suitable for both high-speed cutting and interrupted cutting. Although it exhibits excellent cutting performance even in
Comparative surface-coated cermet member 3, which corresponds to the conventional surface-coated cermet member, suffered from chipping on all cutting edges during interrupted cutting due to insufficient impact resistance, and as seen in comparative surface-coated cermet members 1 to 6, cermet It is clear that if any of the component composition, intermediate layer, and surface coating layer of the member deviates from the scope of the present invention, satisfactory cutting performance will not be exhibited. As mentioned above, the surface-coated cermet member of the present invention has particularly excellent impact resistance, and also has excellent plastic deformation resistance and abrasion resistance.
It exhibits excellent cutting performance when used as a cutting tool for high-speed cutting of steel and heavy-duty cutting such as high-cutting and high-feed cutting.

Claims (1)

[Scope of Claims] 1. A composite metal containing Ti, W, and one or more metals from Groups 4a, 5a, and 6a of the Periodic Table of the Elements excluding Ti and W as hard phase forming components. Carbonitride solid solution: 60 to 95%, one or two of Ni and Co as binder phase forming components, and unavoidable impurities: the rest, on the surface of a cermet member having a composition (the above weight %). Average layer thickness consisting of a titanium coating layer in which the binder phase forming component is diffused:
Ti nitrides, carbonitrides, carbonates, and carbonitrides, and
A surface-coated cermet member for a cutting tool, comprising a surface coating layer consisting of a single layer or a multilayer of two or more types of Al oxides, with an average layer thickness of 0.5 to 10 μm. 2. Composite metal carbonitride solid solution containing Ti, W, and one or more metals from groups 4a, 5a, and 6a of the periodic table of the elements excluding Ti and W as hard phase forming components: 60 ~95%, Mo as a bonding phase forming component: 1~20%, W:
1 to 20%, and one or more of Al: 0.1 to 2%, one or two of Ni and Co as binder phase forming components, and the remainder of unavoidable impurities ( average layer thickness consisting of a titanium carbide coating layer in which the binder phase-forming component is diffused on the surface of a cermet member having an average thickness of
Ti nitrides, carbonitrides, carbonates, and carbonitrides, and
A surface-coated cermet member for a cutting tool, which is formed by forming a surface coating layer consisting of a single layer of one type of Al oxide, or indeed a multilayer of two or more types, with an average layer thickness of 0.5 to 10 μm.