JP4711177B2 - Surface coated cemented carbide cutting tool with excellent wear resistance due to lubricity coating layer - Google Patents

Description

  This invention demonstrates excellent wear resistance even when cutting various types of steel and cast iron and other non-ferrous materials such as Al alloys and Cu alloys, especially at high speeds. The present invention relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a coated cemented carbide tool).

  In general, as a coated carbide tool, a throw-away tool that is detachably attached to the tip of a cutting tool for turning and planing of various steel and cast iron and other non-ferrous materials such as Al alloy and Cu alloy. There are drills and miniature drills used for inserts, drilling and cutting, and solid type end mills used for chamfering, grooving, shoulder processing, etc. A slow-away end mill tool that performs a cutting process in the same manner as an end mill is known.

In addition, as the above coated carbide tool,
As a lubricating coating layer on the surface of a cemented carbide substrate made of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) cermet,
(A) Nitriding formed in a sputtering apparatus using a Ti target as a cathode electrode (evaporation source) in a reaction atmosphere consisting of a mixed gas of nitrogen and Ar, or a mixed gas of hydrocarbon decomposition gas and nitrogen and Ar Through a tight junction layer consisting of either or both of a titanium (hereinafter referred to as TiN) layer and a titanium carbonitride (hereinafter referred to as TiCN) layer, and having an average layer thickness of 0.1 to 3 μm,
(B) Using a WC target as a cathode electrode (evaporation source) in a sputtering apparatus, formed in a reaction atmosphere composed of a hydrocarbon decomposition gas and an Ar mixed gas, and measured with an Auger spectrometer
W: 5 to 20 atomic%,
Coated carbide tool comprising a surface lubrication layer comprising an amorphous carbon-based lubrication layer having a composition comprising carbon and the inevitable impurities and having an average layer thickness of 1 to 13 μm. It has been known.

  Further, the conventional coated carbide tool is, for example, a schematic plan view in FIG. 3A and a schematic front view in FIG. 3B, and a sputtering apparatus in which the cathode electrode (evaporation source) is a Ti target, A cathode electrode (evaporation source) is loaded on the rotating table installed at the center of a vapor deposition apparatus equipped with a sputtering apparatus for a WC target so as to rotate freely. For example, under the conditions shown in Table 1, A glow discharge is generated to form a tight bonding layer consisting of one or both of a TiN layer and a TiCN layer on the surface of the cemented carbide substrate, and then under the same conditions as shown in Table 1, It is also known that it is produced by vapor-depositing a surface lubricating layer comprising the above amorphous carbon-based lubricating layer.

Japanese Patent Laid-Open No. 07-164211 Japanese translation of PCT publication No. 2002-513087

  In recent years, the performance of cutting machines has been remarkable. On the other hand, there is a strong demand for labor saving and energy saving and further cost reduction for cutting. With this trend, cutting tends to be faster. In coated carbide tools, there is no problem when used under normal cutting conditions, but especially when used for high-speed cutting, the surface lubricating layer of the lubricating coating layer is configured. The progress of wear of the amorphous carbon-based lubricating layer is extremely fast, and as a result, the service life is reached in a relatively short time.

In view of the above, the inventors of the present invention, therefore, are coated carbides that exhibit excellent wear resistance in the amorphous carbon-based lubricating layer that constitutes the surface lubricating layer of the lubricating coating layer, particularly in high-speed cutting. As a result of research to develop tools,
(A) For example, the vapor deposition apparatus shown in the schematic plan view and schematic front view in FIGS. 2 (a) and 2 (b), that is, the vapor deposition apparatus for forming the lubricating coating layer of the conventional coated carbide tool shown in FIG. In each of the sputtering apparatus, a magnetic field is formed by the electromagnetic coil provided with an electromagnetic coil as a magnetron sputtering apparatus, and a surface lubricating layer (amorphous carbon-based lubrication is performed under the conditions shown in Table 2, for example. Layer) is formed, the surface lubrication layer formed as a result of this is observed on the substrate of the carbon-based amorphous body, as shown in the schematic diagram of FIG. The fine particles of the titanium carbonitride compound (hereinafter referred to as “crystalline Ti (C, N) compound fine particles”) have a distributed structure.

(B) When the surface lubricating layer of (a) is formed, the flow rates of hydrocarbon, nitrogen, and Ar introduced as reaction gases into the vapor deposition apparatus, and the WC target and Ti target of the magnetron sputtering apparatus are applied. The surface lubricating layer is measured with an Auger spectroscopic analyzer,
W: 5-15 atomic%,
Ti: 21-35 atomic%,
Nitrogen: 21-35 atomic%,
As a result, the surface lubrication layer formed as a result has a dispersion distribution effect of crystalline Ti (C, N) -based fine particles and a magnetic field generated by the electromagnetic coil. Hardness is remarkably improved due to the fine graining effect during film formation.

(C) Although the TiN layer and the TiCN layer constituting the adhesion bonding layer of the lubricity coating layer of the conventional coated carbide tool have excellent adhesion to the surface of the carbide substrate, the surface lubrication layer (amorphous carbon-based lubrication) The adhesiveness to the layer) cannot be said to be sufficient, and chipping is likely to occur at the cutting edge due to insufficient adhesion of the surface lubrication layer in high-speed cutting that requires particularly high adhesion.

(D) As a cathode electrode (evaporation source) of the above (a), a magnetron sputtering apparatus provided with a WC target and a Ti target is used. First, under the conditions shown in Table 2, as an adhesion bonding layer, a TiN layer and a TiCN layer are formed. Either or both of them are formed, and this close-bonding layer has an effect of crystal refining by film formation in a magnetic field by an electromagnetic coil, so that the strength is improved. Next, under the conditions shown in Table 2 Film formation in a magnetic field in a reaction atmosphere composed of a hydrocarbon decomposition gas and a mixed gas of nitrogen and Ar, that is, among the above conditions for forming a tight junction layer, N ₂ gas flow rate: 200 to 300 sccm and Ti target output: 8 to 15 kW , the formation conditions of the surface lubricating layer _{N 2} gas flow rate: 100～150Sccm and Ti targets output: continuously 3~8kW Other multi-stepwise reduced, at the same time hydrocarbon gas flow rate, for example _C 2 _{H 2} gas flow rate to 50～120Sccm, WC target output amorphous under conditions continuously or multi-stepwise increased 3~6kW When a carbonaceous lubricating layer (hereinafter referred to as a base lubricating layer) is formed, the base lubricating layer has a Ti, nitrogen, carbon, and W component content ratio along the thickness of the interface portion of the adhesive bonding layer. Since it has a component concentration change structure that changes continuously or in multiple steps from the content ratio in the interface portion of the surface lubrication layer to the adhesion layer and the surface lubrication layer Therefore, a coated carbide tool formed by vapor-depositing a lubricating coating layer comprising the above-mentioned adhesion bonding layer, base lubricating layer, and surface lubricating layer is a W component of the surface lubricating layer. Combined with the effect of improving the strength, the chip has no chipping (small chipping) even in high-speed cutting, and it exhibits excellent wear resistance over a long period of time.
The research results shown in (a) to (d) above were obtained.

This invention was made based on the above research results,
A lubricating coating layer formed by vapor deposition on the surface of a cemented carbide substrate made of a WC-based cemented carbide alloy or TiCN-based cermet is composed of an adhesion bonding layer, a base lubrication layer, and a surface lubrication layer,
(A) The adhesion bonding layer has an average layer thickness of 0.1 to 3 μm, and in a magnetron sputtering apparatus, using a Ti target as a cathode electrode (evaporation source), a mixed gas of nitrogen and Ar, or Either or both of a TiN layer and a TiCN layer formed in a magnetic field in a reaction atmosphere composed of a hydrocarbon decomposition gas and a mixed gas of nitrogen and Ar,
(B) The surface lubricating layer has an average layer thickness of 1 to 10 μm, and in a magnetron sputtering apparatus, using a WC target and a Ti target as a cathode electrode (evaporation source), Films are formed in a magnetic field in a reaction atmosphere consisting of a mixed gas of nitrogen and Ar, and measured with an Auger spectrometer.
W: 5-15 atomic%,
Ti: 21-35 atomic%,
Nitrogen: 21-35 atomic%,
And the remainder of the composition is composed of carbon and inevitable impurities, and the crystalline Ti (C, N) compound fine particles are dispersed and distributed on the base of the carbon-based amorphous body by observation with a transmission electron microscope. An amorphous carbon-based lubricating layer having a structure,
And in addition,
(C) Decomposing hydrocarbons using the WC target and Ti target as the cathode electrode (evaporation source) in the base lubricating layer having an average layer thickness of 0.1 to 3 μm and using a magnetron sputtering apparatus. Films are formed in a magnetic field in a reaction atmosphere composed of a mixed gas of gas, nitrogen, and Ar, and the content ratios of Ti, nitrogen, carbon, and W components are included in the interface portion of the adhesive bonding layer along the layer thickness. An amorphous carbon-based lubricating layer having a component concentration changing structure that continuously or multistagely changes from the proportion to the content proportion at the interface portion of the surface lubricating layer,
The lubricated coating layer is characterized by a coated carbide tool that exhibits excellent wear resistance.

Next, in the coated carbide tool of the present invention, the reason why the adhesion bonding layer, the base lubricating layer, and the surface lubricating layer constituting the lubricating coating layer are numerically limited as described above will be described.
(A) Average layer thickness of tight junction layer The tight junction layer consisting of either or both of the TiN layer and TiCN layer has improved strength due to the effect of crystal grain refinement by film formation in a magnetic field, and the surface of the carbide substrate. In addition, since the content ratio of Ti and nitrogen at the interface between the base lubricating layer and the adhesive bonding layer is the highest, the adhesive layer and the base lubricating layer Excellent adhesion is ensured in the middle, and adhesion to the cemented carbide substrate surface and the base lubricating layer is further improved by film formation in a magnetic field, but when the average layer thickness is less than 0.1 μm, The desired excellent adhesive bondability cannot be ensured. On the other hand, when the average layer thickness exceeds 3 μm, it becomes easy to cause thermoplastic deformation particularly at high speed cutting, which is a cause of occurrence of chipping in the lubricating coating layer. From becoming an average layer thickness is defined as 0.1 to 3 m.

(B) W content of surface lubrication layer W component has the effect | action which forms the base material of a surface lubrication layer, and improves the intensity | strength of this, However, If the content is less than 5 atomic%, desired intensity | strength improvement effect is carried out. On the other hand, when the content exceeds 15 atomic%, the lubricity is drastically lowered. Therefore, the content is determined to be 5 to 15 atomic%.

(C) Ti and N contents of surface lubrication layer Ti component, N component, and C (carbon) component are combined under film formation of magnetic field, and crystalline Ti (C, N) is present as a compound compound fine particle, and has the effect of remarkably improving the hardness of the surface lubricating layer. However, when the content of any of Ti and N components is less than 21 atomic%, Ti (C , N) the proportion present as system-based fine particles becomes too small to ensure the desired high hardness, while if the content of any of the Ti and N components exceeds 35 atomic%, the strength and Since the lubricity is abruptly lowered, the contents are determined to be Ti: 21 to 35 atomic% and N: 21 to 35 atomic%, respectively.

(D) Average layer thickness of surface lubricating layer If the average layer thickness is less than 1 μm, the desired lubricity and wear resistance improvement effect cannot be ensured, while if the average layer thickness exceeds 10 μm, the cutting edge Since the chipping is likely to occur in the part, the average layer thickness is set to 1 to 10 μm.

(E) Average layer thickness of the base lubricating layer The base lubricating layer has the highest Ti and nitrogen content at the interface with the adhesive bonding layer, and the highest W component content at the interface of the surface lubricating layer. Crystalline Ti (C, N) having a component concentration changing structure having substantially the same component composition as that of the surface lubricant layer, and dispersed and distributed in the base of the carbon-based amorphous body. ) System compound fine particles are continuously or multistagely reduced from the interface with the adhesive layer to the interface of the surface lubricant layer, and as a result, both the adhesive layer and the surface lubricant layer are firmly There is an effect of tightly bonding and contributing to a further improvement in the adhesion of the lubricating coating layer to the surface of the carbide substrate, but if the average layer thickness is less than 0.1 μm, a desired improvement effect can be obtained in the above function. While the average layer thickness is 3 μm Exceeds the, since the easily chipping occurs in the cutting edge, defining the average layer thickness and 0.1 to 3 m.

  In the coated carbide tool of the present invention, the surface lubrication layer constituting the lubricity coating layer is firmly adhered and bonded to the carbide substrate via the adhesion bonding layer and the base lubrication layer, and the hardness is carbon. Since the crystalline Ti (C, N) compound fine particles dispersed and distributed in the ultrafine state by magnetic field film formation are remarkably improved on the base of the amorphous amorphous body, the carbon-based amorphous Combined with the fact that the body of the body has high strength due to the action of the W component, steel materials such as various steels and cast iron, as well as high-speed cutting of Al alloys and Cu alloys, no chipping occurs It exhibits excellent wear resistance over a long period of time.

  Next, the coated carbide tool of the present invention will be specifically described with reference to examples.

As raw material powders, WC powder, TiC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, and Co powder all having an average particle diameter of 0.8 to 3 μm are prepared. Compounded in the composition shown in Table 3 and wet mixed in a ball mill for 84 hours, dried, and then press-molded into a green compact at a pressure of 100 MPa. The green compact was heated at 1400 ° C. in a vacuum of 6 Pa. Sintered under the condition of holding time, and manufactured a carbide substrate material for cutting carbon steel and a carbide substrate material for cutting Al alloy and Cu alloy, both of which are made of WC-based cemented carbide. The base material is subjected to honing of R: 0.03 on the cutting edge portion to form carbide bases A-1 to A-10 having a chip shape of ISO standard TNMG160408, and also for cutting the Al alloy and Cu alloy. Carbide The body material was cemented carbide substrate A-1'~A-10 'having a tip shape of ISO standard · TEGX160304R subjected to abrasive machining.

Further, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC, all having an average particle diameter of 0.5 to 2 μm. Prepare powder, Co powder, and Ni powder, mix these raw material powders into the composition shown in Table 4, wet mix with ball mill for 84 hours, dry, and press mold into green compact with 100 MPa pressure Then, this green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, both of which were made of a carbide substrate carbide substrate made of TiCN cermet, an Al alloy and a Cu alloy. A carbide substrate material for cutting is manufactured, and the cutting edge portion is subjected to a honing process of R: 0.03 to form a chip shape of ISO standard / TNMG160408. Carbide substrates B-1 to B-6, and the carbide substrates B-1 ′ having a chip shape of ISO standard TEGX160304R by polishing the Al and Cu alloy carbide substrate materials. To B-6 ′.

Then, each of the above-mentioned superhard substrates A-1, 1 'to A-10, 10' and B-1, 1 'to B-6, 6' was ultrasonically cleaned in acetone and dried. 2, a plurality of cemented carbide substrates are mounted in a ring shape at a predetermined distance in the radial direction from the central axis of the rotary table in the vapor deposition apparatus shown in FIG. 2, and the cathode electrode of the magnetron sputtering apparatus on one side (Evaporation source), purity: 99.9 mass% Ti target, and cathode electrode (evaporation source) of the other side magnetron sputtering apparatus, purity: 99.6 mass% WC target across the rotary table Place and
(A) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.01 Pa, and the inside of the apparatus is heated to 200 ° C. with a heater, and then Ar gas is introduced into the apparatus and Ar at a pressure of 0.5 Pa is introduced. In this state, a bias voltage of −800 V was applied to the carbide substrate rotating while rotating on the turntable in this state, and the surface of the carbide substrate was cleaned with Ar gas bombardment for 20 minutes.
(B) Next, both are applied to the electromagnetic coils of both magnetron sputtering devices arranged opposite to the vapor deposition device under the conditions of voltage: 50 V and current: 10 A, and the magnetic flux density in the mounting portion of the cemented carbide substrate is 140 G ( In addition, a Gaussian magnetic field is formed and nitrogen and Ar are introduced as reaction gases at a rate of nitrogen flow rate: 250 sccm and Ar flow rate: 230 sccm while the heating temperature in the vapor deposition apparatus is 400 ° C. Introducing C ₂ H ₂ , nitrogen, and Ar as a reaction gas composed of a mixed gas of nitrogen and Ar at a rate of C ₂ H ₂ flow rate: 40 sccm, nitrogen flow rate: 250 sccm, Ar flow rate: 230 sccm, a reaction atmosphere of a mixed gas of 1Pa of _C 2 decomposed gas of _{H 2} and nitrogen and Ar, the cathode electrode of the Ti target (evaporation ) Is applied with a sputtering power of 12 kW (frequency: 40 kHz), while glow discharge is generated on the cemented carbide substrate under the condition that a bias voltage of −100 V is applied. Forming a tight junction layer consisting of either or both of the TiN layer and TiCN layer of the target layer thickness shown in Tables 5 and 6;
(C) Next, the degree of vacuum in the vapor deposition apparatus is 0.01 Pa, the magnetic flux density in the mounting portion of the carbide substrate is 140 G, the heating temperature in the vapor deposition apparatus is 400 ° C., and the bias voltage applied to the carbide substrate is −100 V. while maintaining the, the _C 2 _{H 2} and nitrogen and Ar as the reaction _gas, C 2 _{H 2} flow rate: 40 sccm, flow rate of nitrogen: 250 sccm, Ar flow rate: introduced at a rate of 230Sccm, 1 Pa of _C 2 _{H 2} of The reaction atmosphere is composed of a cracked gas, a mixed gas of nitrogen and Ar. Among these, the C ₂ H ₂ flow rate and the nitrogen flow rate correspond to the target layer thicknesses shown in Tables 3 and 4, and the C ₂ H ₂ flow rate is up to 100 sccm, respectively. While continuously increasing, while the nitrogen flow rate is continuously decreased to 130 sccm, at the same time the output of the Ti target (frequency remains the same 40 kHz) from 12 kW to 6 kW In accordance with the target layer thicknesses shown in Tables 5 and 6, continuously, the application to the WC target is started, and the output corresponding to the target layer thickness is up to 5 kW (frequency is 40 kHz). By continuously increasing the content ratio of Ti, nitrogen, carbon, and W component, the content ratio at the interface portion of the adhesion layer is continuously from the content ratio at the interface portion of the surface adhesion layer along the layer thickness. Forming a base lubricating layer composed of an amorphous carbon-based lubricating layer having a component concentration changing structure that varies with the target layer thicknesses shown in Tables 5 and 6;
(D) Further, as shown in Table 2, the degree of vacuum in the vapor deposition apparatus, the magnetic flux density at the mounting portion of the carbide substrate, the heating temperature in the vapor deposition apparatus, and the bias voltage applied to the carbide substrate are kept the same. In the vapor deposition apparatus, C ₂ H ₂ (hydrocarbon), nitrogen, and Ar are used as reaction gases. C ₂ H ₂ flow rate: 50 to 120 sccm, nitrogen flow rate: 100 to 150 sccm, Ar flow rate: 200 to 250 sccm The reaction atmosphere is a mixed gas of 1 Pa of C ₂ H ₂ decomposition gas and nitrogen and Ar, and the cathode electrode (evaporation source) of the WC target of both the magnetron sputtering devices. Output: 3 to 6 kW (Frequency: 40 kHz) Predetermined sputtering power, within the same Ti target, Output: 3 to 8 kW (Frequency: 40 kHz) The surface lubricating layer comprising the amorphous carbon-based lubricating layer having the target composition and the target layer thickness similarly shown in Tables 5 and 6 under the condition that the predetermined sputtering power is applied simultaneously is the target layer thickness shown in Tables 3 and 4 The surface coated cemented carbide throwaway tip (hereinafter referred to as the present coated carbide tip) 1,1'-16,16 'as the coated carbide tool of the present invention is produced by vapor deposition. did.

For comparison purposes, the surfaces of the superhard substrates A-1, 1 'to A-10, 10' and B-1, 1 'to B-6, 6' are ultrasonically cleaned in acetone. Then, in a dry state, the cathode electrode (evaporation source) shown in FIG. 3 is a Ti target sputtering device and the cathode electrode (evaporation source) is a WC target sputtering device facing each other on the rotary table of the evaporation device, A plurality of cemented carbide substrates are attached in a ring shape at a predetermined distance from the central axis in the radial direction
(A) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.01 Pa, and the inside of the apparatus is heated to 200 ° C. with a heater, and then Ar gas is introduced into the apparatus and Ar at a pressure of 0.5 Pa is introduced. In this state, a bias voltage of −800 V was applied to the carbide substrate rotating while rotating on the turntable in this state, and the surface of the carbide substrate was cleaned with Ar gas bombardment for 20 minutes.
(B) Next, in a state where the heating temperature in the vapor deposition apparatus is 400 ° C., nitrogen and Ar are introduced into the apparatus at a rate of nitrogen flow rate: 250 sccm, Ar flow rate: 230 sccm, and 1 Pa of nitrogen A reaction atmosphere consisting of a mixed gas of Ar and Ar, or C ₂ H ₂ , nitrogen and Ar as reaction gases are introduced at a rate of C ₂ H ₂ flow rate: 40 sccm, nitrogen flow rate: 250 sccm, Ar flow rate: 230 sccm, and 1 Pa The reaction atmosphere is composed of a C ₂ H ₂ decomposition gas and a mixed gas of nitrogen and Ar, and a sputtering power of 12 kW (frequency: 40 kHz) is applied to the cathode electrode (evaporation source) of the Ti target, while the above carbide Tables 7 and 8 show the surface of the cemented carbide substrate by generating glow discharge under the condition that a bias voltage of −100 V is applied to the substrate. One of the target layer thickness TiN layer and TiCN layer, or the adhesion bonding layer consisting of both deposited form,
(C) Next, in the state where the heating temperature in the vapor deposition apparatus is the same 400 ° C. and the bias voltage applied to the cemented carbide substrate is the same −100 V, C ₂ H ₂ and Ar are replaced with a C ₂ H ₂ flow rate: 50˜. 120 sccm, Ar flow rate: Introduced at a predetermined flow rate in the range of 200 to 250 sccm to form a reaction atmosphere consisting of a mixed gas of 1 Pa of C ₂ H ₂ decomposition gas and Ar, and a cathode electrode (evaporation source) of the WC target ) Under the condition that a predetermined sputtering power within a range of output: 3 to 6 kW (frequency: 40 kHz) is applied, the target composition and target layer thickness shown in Tables 7 and 8 are also formed on the adhesive bonding layer. By forming a surface lubrication layer consisting of an amorphous carbon-based lubrication layer by vapor deposition, a comparative surface-coated cemented carbide throwaway tip (hereinafter referred to as a comparative coated carbide tip) equivalent to a conventional coated carbide tool. The U) 1,1'～16,16 'was produced, respectively.

Next, the coated carbide tips 1, 1 'to 16, 16' of the present invention and the comparative coated carbide tips 1, 1 'to 16, 16' are screwed to the tip of the tool steel tool with a fixing jig. In the state
Work material: JIS A4032 round bar,
Cutting speed: 600 m / min. ,
Cutting depth: 1.2mm,
Feed: 0.6 mm / rev. ,
Cutting time: minutes,
A dry high-speed cutting test of an Al alloy under the conditions (referred to as cutting condition A) (normal cutting speed is 350 m / min.),
Work material: JIS C6301 round bar,
Cutting speed: 150 m / min. ,
Incision: 2.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
A dry high-speed cutting test of a Cu alloy under the conditions (cutting condition B) (normal cutting speed is 80 m / min.),
Work material: JIS / S35C round bar,
Cutting speed: 350 m / min. ,
Cutting depth: 2mm,
Feed: 0.3 mm / rev. ,
Cutting time: 15 minutes,
The carbon steel was subjected to a wet high-speed cutting test (normal cutting speed is 220 m / min.) Under the above conditions (referred to as cutting conditions C). In any cutting test, the flank wear width of the cutting edge was measured. The measurement results are shown in Tables 5-8.

As raw material powders, medium coarse WC powder having an average particle size of 4.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Powder, 1.8 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C (mass ratio, TiC / WC = 50/50) powder, and 1 .8 μm Co powder was prepared, each of these raw material powders was blended into the blending composition shown in Table 9, further added with wax, ball milled in acetone for 72 hours, dried under reduced pressure, and then pressed into a predetermined shape at a pressure of 100 MPa. The green compacts were press-molded, and these green compacts were heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a 6 Pa vacuum atmosphere. After holding at temperature for 1 hour, sintering under furnace cooling conditions Three types of sintered carbide rod forming bodies for forming a carbide substrate having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three kinds of sintered rods for round bar were ground and shown in Table 9. In combination, a carbide substrate (end mill) having a diameter of 4 mm × 13 mm, a length of 6 mm × 13 mm, a size of 10 mm × 22 mm, and a size of 20 mm × 45 mm, and a four-blade square with a twist angle of 30 degrees. ) C-1 to C-8 were produced.

  Then, these carbide substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and charged in the vapor deposition apparatus shown in FIG. Under the same conditions, the adhesion layer composed of either or both of the TiN layer and TiCN layer having the target layer thickness shown in Table 12, and the base lubricating layer composed of the amorphous carbon-based lubricating layer, and also shown in Table 10 The surface-coated cemented carbide end mill of the present invention as a coated carbide tool of the present invention (hereinafter, coated with the present invention) is formed by vapor-depositing a surface lubricating layer comprising an amorphous carbon-based lubricating layer having a target composition and a target layer thickness. (Referred to as carbide end mills) 1 to 8 were produced.

  Further, for the purpose of comparison, the above-mentioned carbide substrates (end mills) C-1 to C-8 were ultrasonically washed in acetone and dried, and charged in the vapor deposition apparatus shown in FIG. Under the same conditions as in Example 1 above, the adhesive bonding layer composed of either or both of the TiN layer and TiCN layer having the target layer thickness shown in Table 11, and the target composition and target layer thickness also shown in Table 11 are used. By forming a surface lubrication layer comprising an amorphous carbon-based lubrication layer by vapor deposition, comparative surface-coated cemented carbide end mills (hereinafter referred to as comparative coated carbide end mills) 1 to 8 corresponding to conventional coated carbide tools are produced. Each was manufactured.

Next, of the present invention coated carbide end mills 1-8 and comparative coated carbide end mills 1-8, the present invention coated carbide end mills 1-3 and comparative coated carbide end mills 1-3 are as follows:
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / A5052 plate material,
Cutting speed: 300 m / min. ,
Axial cut: 3.5mm,
Radial notch: 0.7mm,
Table feed: 2400 mm / min,
With respect to the dry high-speed side cutting test of Al alloy under the following conditions (normal cutting speed is 180 m / min.), The coated carbide end mills 4 to 6 of the present invention and the conventional coated carbide end mills 4 to 6 are as follows:
Work material: Plane dimension: 100 mm x 250 mm, thickness: 50 mm JIS C6301 plate material,
Cutting speed: 110 m / min. ,
Axial cut: 6mm,
Radial notch: 1.5mm,
Table feed: 2100 mm / min,
With respect to the Cu alloy dry high-speed side cutting test under the conditions (normal cutting speed is 60 m / min.), The present invention coated carbide end mills 7 and 8 and the comparative coated carbide end mills 7 and 8
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / S45C plate,
Cutting speed: 350 m / min. ,
Axial cut: 8mm,
Radial notch: 1.5mm,
Table feed: 2200 mm / min,
Carbon steel dry high-speed side cutting test under normal conditions (normal cutting speed is 200 m / min.) Is performed, and the flank wear width of the outer peripheral edge of the cutting edge is the service life of each side cutting test The cutting length up to 0.1 mm, which is a standard, was measured. The measurement results are shown in Tables 10 and 11, respectively.

    The diameters produced in Example 2 above were 8 mm (for forming carbide substrates C-1 to C-3), 13 mm (for forming carbide substrates C-4 to C-6), and 26 mm (for carbide substrates C-). 7, for C-8 formation), from these three types of round bar sintered bodies, the diameter x length of the groove forming portion is 4 mm x 13 mm (by grinding), respectively. Carbide substrates D-1 to D-3), 8 mm × 22 mm (Carbide substrates D-4 to D-6), and 16 mm × 45 mm (Carbide substrates D-7 and D-8), and all Carbide substrates (drills) D-1 to D-8 having a two-blade shape with a twist angle of 30 degrees were manufactured.

  Then, the cutting edges of these carbide substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then loaded into the vapor deposition apparatus shown in FIG. Then, under the same conditions as in the first embodiment, the adhesive layer composed of either or both of the TiN layer and the TiCN layer having the target layer thickness shown in Table 12, and the base lubricating layer composed of the amorphous carbon-based lubricating layer Further, the surface-coated cemented carbide alloy of the present invention as the coated carbide tool of the present invention is formed by vapor-depositing a surface lubricating layer comprising an amorphous carbon-based lubricating layer having the target composition and target layer thickness shown in Table 12 Drills (hereinafter referred to as the present invention coated carbide drills) 1 to 8 were produced.

  For comparison purposes, the cutting edges of the above-mentioned carbide substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried, as shown in FIG. In the vapor deposition apparatus, under the same conditions as in Example 1 above, a tight junction layer consisting of either or both of the TiN layer and TiCN layer having the target layer thickness shown in Table 13, and also shown in Table 13 A comparative surface-coated cemented carbide drill equivalent to a conventional coated carbide tool (hereinafter referred to as a comparative coated carbide drill) is formed by vapor-depositing a surface lubricating layer consisting of an amorphous carbon-based lubricating layer having a target composition and target layer thickness. 1) to 8 were produced.

Next, of the present invention coated carbide drills 1-8 and comparative coated carbide drills 1-8, for the present invention coated carbide drills 1-3 and comparative coated carbide drills 1-3,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / ADC12 plate material,
Cutting speed: 120 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 10mm,
With respect to the Al alloy wet high-speed drilling test (normal cutting speed is 80 m / min.), The coated carbide drills 4 to 6 and the comparative coated carbide drills 4 to 6 of the present invention,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / C2801 plate material,
Cutting speed: 130 m / min. ,
Feed: 0.5mm / rev,
Hole depth: 15mm,
With respect to the Cu alloy wet high-speed drilling cutting test under the conditions (normal cutting speed is 100 m / min.), The coated carbide drills 7 and 8 of the present invention and the comparative coated carbide drills 7 and 8 are as follows:
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S17C plate,
Cutting speed: 210 m / min. ,
Feed: 0.8mm / rev,
Hole depth: 22mm,
Wet high-speed drilling test of carbon steel under normal conditions (normal cutting speed is 90 m / min.), And any wet drilling test (using water-soluble cutting oil) is used to relieve the cutting edge surface. The number of drilling processes until the surface wear width reached 0.3 mm was measured. The measurement results are shown in Tables 12 and 13, respectively.

  As a result, the coated carbide tips 1, 1 'to 16, 16' of the present invention as the coated carbide tool of the present invention, the coated carbide end mills 1 to 8 of the present invention, and the coated carbide drills 1 to 8 of the present invention, In addition, the comparative coated carbide tips 1, 1 'to 16, 16' corresponding to the conventional coated carbide tool, the comparative coated carbide end mills 1 to 8, and the non-coated lubricant layers constituting the comparative coated carbide drills 1 to 8 The composition of the crystalline carbon-based lubricating layer was measured using an Auger spectroscopic analyzer, and the layer thickness was measured using a scanning electron microscope. Both of the target composition and the target layer thickness were substantially the same as the target composition and the target layer thickness ( When the structure was observed using a transmission electron microscope, the coated carbide tool of the present invention had a crystalline Ti ( A set in which C, N) compound fine particles are dispersed and distributed. It is shown, whereas the it conventional coating carbide tools showed tissue of a single phase of the carbon-based amorphous substance.

From the results shown in Tables 5 to 13, the surface lubrication layer has an amorphous carbon-based lubrication having a structure in which crystalline Ti (C, N) compound fine particles are dispersed and distributed on a carbon-based amorphous body. The coated carbide tool of the present invention consisting of a layer exhibits excellent wear resistance even when cutting Al alloy, Cu alloy, and steel under high speed conditions, while surface lubrication In the conventional coated carbide tool (comparative coated carbide tool) whose layer has a structure composed of a single phase of a carbon-based amorphous body, the progress of wear of the surface lubricating layer is extremely fast under high-speed cutting conditions. It is clear that the service life is reached in a short time.
As described above, the coated carbide tool of the present invention has excellent resistance not only to cutting under normal conditions, but also when cutting various kinds of work materials under high-speed cutting conditions. Since it exhibits wearability, it can be satisfactorily deal with labor saving and energy saving in cutting, and further cost reduction.

It is a schematic diagram which shows the result of having observed the structure | tissue of the amorphous carbon type lubricating layer which comprises the surface lubricating layer of the coated carbide tool of this invention using the transmission electron microscope. Lubricating coating layer of the coated carbide tool of the present invention (deposition device used to form an adhesion bonding layer, a base lubricating layer, and a surface lubricating layer is shown, (a) is a schematic plan view, (b) is a schematic plan view. It is a front view. The vapor deposition apparatus used for forming the lubricity coating layer (adhesion joining layer and surface lubrication layer) of the conventional coated carbide tool (comparative coated carbide tool) is shown, (a) is a schematic plan view, and (b) is a schematic diagram. It is a front view.

Claims (1)

A lubricating coating layer formed by vapor deposition on the surface of a cemented carbide substrate made of tungsten carbide based cemented carbide or titanium carbonitride cermet consists of an adhesive bonding layer, a base lubrication layer, and a surface lubrication layer,
(A) The adhesion bonding layer has an average layer thickness of 0.1 to 3 μm, and in a magnetron sputtering apparatus, using a Ti target as a cathode electrode (evaporation source), a mixed gas of nitrogen and Ar, or Either or both of a titanium nitride layer and a titanium carbonitride layer formed in a magnetic field in a reaction atmosphere consisting of a hydrocarbon decomposition gas and a mixed gas of nitrogen and Ar,
(B) The surface lubricating layer has an average layer thickness of 1 to 10 μm, and a tungsten carbide target and a Ti target are used as a cathode electrode (evaporation source) in a magnetron sputtering apparatus, and a hydrocarbon decomposition gas Is formed in a magnetic field in a reaction atmosphere consisting of a mixed gas of nitrogen, nitrogen, and Ar, and measured with an Auger spectrometer.
W: 5-15 atomic%,
Ti: 21-35 atomic%,
Nitrogen: 21-35 atomic%,
And the balance is composed of carbon and inevitable impurities, and a structure in which fine particles of crystalline titanium carbonitride compound are dispersed and distributed on the base of the carbon-based amorphous body by observation with a transmission electron microscope. Having an amorphous carbon-based lubricating layer,
And in addition,
(C) The base lubricating layer has an average layer thickness of 0.1 to 3 μm, and a magnetron sputtering apparatus is used as a cathode electrode (evaporation source) with a tungsten carbide target and a Ti target. A film is formed in a magnetic field in a reaction atmosphere composed of a decomposition gas, a mixed gas of nitrogen and Ar, and the content ratios of Ti, nitrogen, carbon, and W components in the interface portion of the adhesive bonding layer are along the layer thickness. An amorphous carbon-based lubricating layer having a component concentration changing structure that continuously or multistagely changes from the content ratio to the content ratio at the interface portion of the surface lubricant layer;
A surface-coated cemented carbide cutting tool that exhibits excellent wear resistance with a lubricious coating layer.

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