JP4771200B2 - Surface-coated cermet cutting tool with excellent wear resistance due to high-speed cutting of heat-resistant alloys - Google Patents

Description

In the present invention, the hard coating layer has excellent thermal conductivity, and also has high-temperature hardness and high-temperature strength. Therefore, Ni alloys, Co alloys, and Ti alloys such as Ti alloys that are particularly accompanied by high heat generation are used. The present invention relates to a surface-coated cermet cutting tool (hereinafter referred to as a coated cermet tool) that exhibits excellent wear resistance when used in high-speed cutting.

In general, for coated cermet tools, throwaway inserts that are detachably attached to the tip of a cutting tool for turning and planing of various steel and cast iron work materials, and drilling of the work material. Drills and miniature drills used in, etc., as well as solid type end mills used for chamfering, grooving, shouldering, etc. of the work material, and the solid type by attaching the throwaway tip detachably A slow-away end mill tool that performs a cutting process in the same manner as an end mill is known.

Further, as a coated cermet tool, on the surface of a cermet base (hereinafter simply referred to as a base) composed of a tungsten carbide (hereinafter referred to as WC) base cemented carbide or a titanium carbonitride (hereinafter referred to as TiCN) base cermet, Having a single phase structure, and
_{Formula: [Ti 1- (X + Y} ) Al X B Y] N ( provided that an atomic ratio, X is 0.50 to .65, Y represents a 0.01-0.10)
A hard coating layer composed of a composite nitride of Ti, Al, and B (boron) [hereinafter referred to as (Ti, Al, B) N] satisfying the above conditions is deposited by an average layer thickness of 2 to 8 μm. A cermet tool is known, and in such a conventional coated cermet tool, the (Ti, Al, B) N layer constituting the hard coating layer has a high-temperature hardness by the component Al, and a high-temperature strength by the Ti, Furthermore, the B component provides thermal conductivity, and the heat removal effect is exhibited especially by the B component. Therefore, it is used for cutting heat-resistant alloys such as Ni alloys, Co alloys, and Ti alloys that generate heat during cutting. It is also known to exhibit excellent wear resistance.

Furthermore, the above coated cermet tool, is charged with an arc ion plating apparatus of the above base is one of physical vapor deposition apparatus shown in example schematic diagram in FIG. 2, in the apparatus with a heater, for example, 500 ° C. A cathode electrode (evaporation source) and an anode electrode in which a Ti—Al—B alloy having a composition corresponding to the composition of the (Ti, Al, B) N layer which is a hard coating layer is set in a state heated to For example, arc discharge is generated under the condition of current: 90 A, for example, and nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa, while the substrate has a bias voltage of, for example, −100 V It is also known that it is produced by vapor-depositing a hard coating layer composed of the (Ti, Al, B) N layer on the surface of the substrate under the condition of applying the above.
Japanese Patent No. 2793696

In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and with this, cutting tends to be faster. In a coated cermet tool, if it is used to cut heat-resistant alloys such as Ni alloys, Co alloys, and Ti alloys with heat generation as described above under normal cutting conditions, a hard coating layer is used. The heat removal effect (thermal conductivity) due to the B component in a certain (Ti, Al, B) N layer works satisfactorily and exhibits a predetermined wear resistance. When used in high-speed cutting conditions involving the above, the thermal conductivity (heat removal effect) of the (Ti, Al, B) N layer is extremely insufficient. Cause uneven wear Plastic deformation occurs, since the so wear progresses to promote considerably, at present, leading to a relatively short time service life.

In view of the above, the present inventors have developed the above-mentioned conventional coated cermet tool in order to develop a coated cermet tool that exhibits excellent wear resistance with a hard coating layer particularly in high-speed cutting of a heat-resistant alloy. As a result of conducting research by focusing on the (Ti, Al, B) N layer that constitutes the hard coating layer,
(A) In the (Ti, Al, B) N layer constituting the hard coating layer, the thermal conductivity improves if the content ratio of the B component is increased. As described above, the conventional (Ti, Al, B) N layer When the B content is about 1 to 10 atomic%, the high thermal conductivity required for high-speed cutting of the heat-resistant alloy cannot be ensured. To satisfy these requirements satisfactorily, To contain 15 to 35 atomic% of B, far exceeding atomic%, while (Ti, Al, B) N layer containing 15 to 35 atomic% of B component is put to practical use as a hard coating layer. It is necessary to contain a predetermined amount of Ti to ensure a predetermined high temperature strength. In this case, however, it is inevitable that the content ratio of the Al component is extremely low, and as a result, the high temperature hardness is extremely low. To be a thing.

(B) the composition _{formula: [Ti 1- (E + F} ) Al E B F] N ( provided that an atomic ratio, E is 0.01 to 0.10, F denotes the 0.15-0.35) satisfies A (Ti, Al, B) N layer having a B content of 15 to 35 atomic%;
_{Formula: [Ti 1- (M + N} ) Al M B N] N ( provided that an atomic ratio, M is 0.25 to 0.40, N denotes the 0.01-0.10) satisfies, relative (Ti, Al, B) N layer with an increased content of Al component,
Are alternately laminated in a state where each layer has an average layer thickness of 5 to 20 nm (nanometers), and the resulting (Ti, Al, B) N layer is formed by the laminated structure of the thin layers. The excellent thermal conductivity of the (Ti, Al, B) N layer (hereinafter referred to as the thin layer A) having a high B content, the B content ratio being lower than that of the thin layer A, and relative And (Ti, Al, B) N layer (hereinafter referred to as thin layer B) having a high Al content ratio has a predetermined relatively high high temperature hardness.

(C) The (Ti, Al, B) N layer having the alternate layered structure of the thin layer A and the thin layer B in (b) above has excellent thermal conductivity and a predetermined value required for high-speed cutting of a heat-resistant alloy. However, since it does not have a sufficiently satisfactory high temperature hardness, it is provided as the upper layer of the hard coating layer, while the lower layer has insufficient thermal conductivity, (Ti, Al, B) N layer having a composition corresponding to the above-mentioned conventional hard coating layer having a high Al component content and excellent high-temperature hardness,
_{Formula: [Ti 1- (X + Y} ) Al X B Y] N ( provided that an atomic ratio, X is 0.50 to .65, Y represents a 0.01-0.10) satisfies the single (Ti, Al, B) N layer of single phase structure,
The resulting hard coating layer has high temperature hardness and high strength in addition to excellent thermal conductivity, so a coated cermet tool formed by vapor deposition of this hard coating layer In the high-speed cutting of the heat-resistant alloy with high heat generation described above, excellent wear resistance is exhibited over a long period of time without occurrence of chipping.
The research results shown in (a) to (c) above were obtained.

This invention has been made based on the above research results, and on the surface of the substrate ,
(A) Both are composed of an upper layer and a lower layer made of (Ti, Al, B) N, the upper layer has an average layer thickness of 0.5 to 1.5 μm, and the lower layer has an average layer thickness of 2 to 6 μm. And
(B) Each of the upper layers has an alternate layered structure of thin layers A and thin layers B each having an average layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Composition formula: [Ti _{1− (E + F)} Al _E B _F ] N (wherein A represents 0.01 to 0.10 and F represents 0.15 to 0.35 in terms of atomic ratio) (Ti , Al, B) N layer,
The thin layer B is
Composition formula: [Ti _{1− (M + N)} Al _M B _N ] N (wherein M is 0.25 to 0.40 and N is 0.01 to 0.10 in atomic ratio) (Ti , Al, B) N layer,
(C) the lower layer has a single phase structure;
_{Formula: [Ti 1- (X + Y} ) Al X B Y] N ( provided that an atomic ratio, X is 0.50 to .65, Y represents a 0.01-0.10) satisfying (Ti , Al, B) N layer,
It is characterized by a coated cermet tool that exhibits excellent wear resistance in high-speed cutting of a heat-resistant alloy, formed by vapor-depositing a hard coating layer comprising:

Next, the reason why the numerical values of the hard coating layer of the coated cermet tool of the present invention are limited as described above will be described.
(A) Composition formula and average layer thickness of the lower layer As described above, the Al component in the (Ti, Al, B) N layer constituting the hard coating layer improves the high temperature hardness, while the Ti component has a high temperature. The strength and further the B component have the effect of improving the thermal conductivity. In the lower layer, the Al component content is relatively increased to provide high high-temperature hardness. If the value is less than 0.50 in terms of the total amount of Ti and B (atomic ratio, the same shall apply hereinafter), the proportion of Ti is relatively high, and the excellent high temperature required for high-speed cutting of heat-resistant alloys Hardness cannot be secured, and the progress of wear is accelerated rapidly. On the other hand, when the X value indicating the Al ratio exceeds 0.65, the Ti ratio is relatively decreased. , The high temperature strength drops sharply, resulting in chipping (slight chipping), etc. Therefore, the X value was determined to be 0.50 to 0.65.
Further, the Y value indicating the ratio of B is the ratio of the total amount of Ti and Al, and if it is less than 0.01, the predetermined thermal conductivity cannot be ensured, while the Y value exceeds 0.10. Then, since a clear decreasing tendency appears in the high temperature strength, the Y value was set to 0.01 to 0.10.
Furthermore, if the average layer thickness is less than 2 μm, it is impossible to impart its own high-temperature hardness to the hard coating layer over a long period of time, resulting in a short tool life, while if the average layer thickness exceeds 6 μm, Since chipping is likely to occur, the average layer thickness was determined to be 2 to 6 μm.

(B) Composition formula of upper layer thin layer A For the B component in (Ti, Al, B) N of the upper layer thin layer A, the content ratio is relatively increased as described above, and the thermal conductivity. It has the effect of improving the heat removal effect of high-temperature cutting of heat-resistant alloys with high heat generation and preventing the occurrence of thermoplastic deformation, but the F value indicating the content ratio is a combination of Ti and Al. If the ratio is less than 0.15, the desired excellent effect cannot be ensured for the above action. On the other hand, if the F value exceeds 0.35, the high-temperature strength decreases rapidly, and this is the upper layer. The F value was determined to be 0.15 to 0.35 because it causes a decrease in the overall high-temperature strength and chipping is likely to occur.
Further, the E value indicating the proportion of Al is the proportion of the total amount of Ti and B, and if it is less than 0.01, the minimum high-temperature hardness cannot be ensured, causing wear promotion, while the E If the value exceeds 0.10, the high-temperature strength decreases and causes chipping, so the E value was determined to be 0.01 to 0.10.

(C) Composition formula of upper layer thin layer B In the upper layer thin layer B, the content ratio of the B component is relatively low, while the content ratio of the Al component is maintained relatively high, The high-temperature hardness of the thin layer A is strengthened, and the lack of high-temperature hardness of the adjacent thin layer A is reinforced, so that the excellent thermal conductivity of the thin layer A and the predetermined high-temperature hardness of the thin layer B are obtained. However, when the M value indicating the Al content in the composition formula is less than 0.25, the Al content is too small to ensure a predetermined high-temperature hardness. As a result, the progress of wear is promoted. On the other hand, when the M value exceeds 0.40, the content ratio of the Ti component is relatively lowered, and the high temperature strength of the upper layer is prevented from being lowered. Therefore, the M value is fixed to 0.25 to 0.40. I tried.
Further, the N value indicating the ratio of B is the ratio of the total amount of Ti and Al. If the N value is less than 0.01, a decrease in the thermal conductivity of the entire upper layer is unavoidable, while the N value exceeds 0.10. Then, the N value was determined to be 0.01 to 0.10 because the high temperature strength decreased and chipping was likely to occur.

(D) Single layer average layer thickness of thin layer A and thin layer B of the upper layer If each layer average layer thickness is less than 5 nm, it is difficult to clearly form each thin layer with the above composition. It is impossible to ensure the desired excellent thermal conductivity and a predetermined high-temperature hardness in the layer, and if the average layer thickness of each layer exceeds 20 nm, each thin layer has a defect, that is, the thin layer A. Insufficient high-temperature hardness and thin layer B cause insufficient heat conductivity to appear locally in the layer, which causes wear to proceed rapidly. It was determined.

(E) Average layer thickness of the upper layer If the average layer thickness is less than 0.5 μm, the excellent thermal conductivity of the layer itself and a predetermined high temperature hardness cannot be imparted to the hard coating layer over a long period of time, resulting in a tool life. On the other hand, if the average layer thickness exceeds 1.5 μm, chipping tends to occur. Therefore, the average layer thickness is set to 0.5 to 1.5 μm.

In the coated cermet tool of the present invention, the hard coating layer is composed of a (Ti, Al, B) N layer, but the upper layer of the hard coating layer has excellent heat by forming the alternate layer structure of the thin layer A and the thin layer B. Heat resistance such as Ni alloy, Co alloy, and Ti alloy with high heat generation, especially because it has conductivity and predetermined high temperature hardness, and the lower layer of the single phase structure has excellent high temperature hardness. Even in high-speed cutting of alloys, the hard coating layer exhibits an excellent heat removal effect, and as a result, it exhibits excellent wear resistance over a long period of time without the occurrence of thermoplastic deformation that causes uneven wear on the cutting edge. Is.

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

As raw material powders, WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder each having a predetermined average particle diameter in the range of 1 to 3 μm, And Co powder are prepared, these raw material powders are blended in the blending composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a compact at a pressure of 100 MPa. The body was sintered in a vacuum of 6 Pa at a temperature of 1400 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to have a chip shape of ISO standard / CNMG120408. It was to form a WC-based cemented carbide substrate a-1 to a-10 of.

Further, as raw material powders, TiCN (weight ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, all having a predetermined average particle diameter in the range of 0.5 to 2 μm, TaC powder, WC powder, Co powder, and Ni powder are prepared. These raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then compacted at a pressure of 100 MPa. The green compact was pressed into a body and sintered in a 2 kPa nitrogen atmosphere at a temperature of 1500 ° C. for 1 hour. After sintering, the cutting edge was subjected to a honing process of R: 0.03. to form a TiCN based cermet substrate B-1 to B-6 having a tip shape of ISO standard · CNMG120408 Te.

(A) Next, each of the substrates A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then the arc ion plating apparatus shown in FIG. Attached along the outer periphery at a predetermined distance in the radial direction from the central axis on the inner rotary table, and corresponded to the target compositions shown in Tables 3 and 4 as cathode electrodes (evaporation sources) on one side, respectively. As the Ti-Al-B alloy for forming the thin layer A of the upper layer having the component composition and the cathode electrode (evaporation source) on the other side, the component compositions corresponding to the target compositions shown in Tables 3 and 4 were also provided. A Ti-Al-B alloy for forming a thin layer B as an upper layer is disposed opposite to the rotary table, and a cathode electrode (along the rotary table at a position shifted by 90 degrees from both the Ti-Al-B alloys). As the evaporation source) The Ku lower layer forming Ti-Al-B alloy having a component composition corresponding to the target composition shown in Tables 3 and 4 is mounted,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the direct current of −1000 V is applied to the base that rotates while rotating on the rotary table. A bias voltage is applied and a current of 100 A is passed between the Ti-Al-B alloy for forming the lower layer and the anode electrode to generate an arc discharge, whereby the substrate surface is bombarded by the Ti-Al-B alloy. Wash and
(C) Introducing nitrogen gas as a reaction gas into the apparatus to form a reaction atmosphere of 3 Pa, applying a DC bias voltage of −100 V to the substrate rotating while rotating on the rotary table, and forming the lower layer A current of 100 A is passed between the Ti-Al-B alloy for use and the anode electrode to generate an arc discharge, so that a single phase having the target composition and target layer thickness shown in Tables 3 and 4 is formed on the surface of the substrate. (Ti, Al, B) N layer having a structure is formed by vapor deposition as a lower layer of the hard coating layer,
(D) Next, the flow rate of nitrogen gas as a reaction gas introduced into the apparatus was adjusted to obtain a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V was applied to the substrate rotating while rotating on the rotary table. In this state, a predetermined current in the range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Ti-Al-B alloy for forming the thin layer A to generate arc discharge, and the surface of the substrate is A thin layer A having a predetermined layer thickness is formed, and after the thin layer A is formed, the arc discharge is stopped. Instead, the thin layer A is formed between the cathode electrode and the anode electrode of the Ti-Al-B alloy for forming the thin layer B. A predetermined current within a range of 200 A is applied to generate arc discharge to form a thin layer B having a predetermined layer thickness, and then the arc discharge is stopped (in this case, the formation of the thin layer B may be started). T for forming the thin layer A again -Formation of thin layer A by arc discharge between cathode electrode and anode electrode of Al-B alloy, and formation of thin layer B by arc discharge between cathode electrode and anode electrode of Ti-Al-B alloy for forming thin layer B An upper layer comprising alternating layers of thin layer A and thin layer B having a target composition and a single target layer thickness along the layer thickness direction is formed on the surface of the substrate by alternately repeating the formation. Similarly, the surface-covered cermet throwaway tips (hereinafter referred to as the present invention-coated tips ) 1 to 16 as the present invention-coated cermet tools are formed by vapor deposition with the overall target layer thicknesses shown in Tables 3 and 4, respectively. Manufactured.

For comparison purposes, these substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating apparatus shown in FIG. A Ti—Al—B alloy having a component composition corresponding to the target composition shown in Table 5 was attached as a cathode electrode (evaporation source), and the apparatus was first evacuated to 0.1 Pa. While maintaining the following vacuum, the inside of the apparatus was heated to 500 ° C. with a heater, a DC bias voltage of −1000 V was applied to the substrate , and the Ti—Al—B alloy of the cathode electrode and the anode electrode by flowing a 100A current to generate an arc discharge, has bombarded washed substrate surface in the Ti-Al-B alloy, and then the reaction atmosphere of 3Pa by introducing nitrogen gas as a reaction gas into the apparatus Rutotomoni, lowering the bias voltage applied to the substrate to -100 V, the Ti-Al-B to generate arc discharge between the cathode electrode and the anode electrode of the alloy, with the substrate A-1 to A-10 and And a hard coating layer composed of a (Ti, Al, B) N layer having a single-phase structure having a target composition and a target layer thickness shown in Table 5 is deposited on each surface of B-1 to B-6. Thus, conventional surface-covered cermet throwaway tips (hereinafter referred to as conventional coated tips ) 1 to 16 as conventional coated cermet tools were manufactured, respectively.

Next, in the state where each of the above-mentioned various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1-16 and the conventional coated chips 1-16,
Work Material: Ni-19.3% Cr-18. 1% Fe-5.4% Cd-4.9% Ta-3.2% Mo-0.9% Ti-0.48% by mass% A round bar of Ni alloy having a composition of Al,
Cutting speed: 65 m / min. ,
Cutting depth: 1.0 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 3 minutes
Dry continuous high-speed cutting test of Ni alloy under the conditions (cutting condition A) (normal cutting speed is 30 m / min.),
Work material: Co having a composition of Co-23.5% Cr-5.9% Mo-2.2% Ni-0.96% Fe-0.57% Si-0.42% C in mass%. 4 vertical grooves with equal intervals in the length direction of the alloy,
Cutting speed: 60 m / min. ,
Cutting depth: 0.5mm,
Feed: 0.15 mm / rev. ,
Cutting time: 4 minutes
Dry interrupted high-speed cutting test of Co alloy under the conditions (cutting condition B) (normal cutting speed is 30 m / min.),
Work material: Round bar of Ti alloy having a composition of Ti-6.14% Al-3.96% V in mass%,
Cutting speed: 80 m / min. ,
Cutting depth: 1.0 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 7 minutes
A dry continuous high-speed cutting test (normal cutting speed is 40 m / min.) Of Ti alloy under the above conditions (referred to as cutting condition C) was carried out, and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 6.

As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 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, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [by mass ratio, TiC / WC = 50/50] powder, and 1 Prepare 8 .mu.m Co powder, mix these raw material powders with the composition shown in Table 7, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and then press 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 round bar sintered bodies for forming a substrate having a diameter of 8 mm, 13 mm, and 26 mm were formed, and further, from the above three types of round bar sintered bodies, the combinations shown in Table 7 were obtained by grinding. A base made of a WC-base cemented carbide having a four-blade square shape with a diameter × length of the cutting edge of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and a twist angle of 30 degrees. (End mill) C-1 to C-8 were produced.

Then, the surfaces of these substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. 1. Under the same conditions as in No. 1, a lower layer composed of a (Ti, Al, B) N layer having a single phase structure with the target composition and target layer thickness shown in Table 8, and Table 8 along the layer thickness direction. A book as a coated cermet tool of the present invention is formed by vapor-depositing an upper layer composed of alternating layers of thin layer A and thin layer B having a target composition and a single target layer thickness with the overall target layer thickness shown in Table 8 as well. Invention surface coated cermet end mills (hereinafter referred to as the present invention coated end mills ) 1 to 8 were produced.

For comparison purposes, the surfaces of the substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. By depositing a hard coating layer composed of a (Ti, Al, B) N layer having a single phase structure with the target composition and target layer thickness shown in Table 9 under the same conditions as in Example 1 above. The conventional surface-coated cermet end mills (hereinafter referred to as conventional coated end mills ) 1 to 8 as conventional coated cermet tools were produced.

Next, of the present invention coated end mills 1 to 8 and the conventional coated end mills 1 to 8, the present coated end mills 1 to 3 and the conventional coated end mills 1 to 3 are as follows:
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm in Dimensions and Mass%, Co-20.3% Cr-14.8% W-10. 1% Ni-1.45% Mn-0. A plate material of Co alloy having a composition of 95% Si-1.04% Fe-0.12% C;
Cutting speed: 40 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 280 mm / min,
The dry high-speed grooving test of the Co alloy under the conditions (normal cutting speed is 25 m / min.), The present invention coated end mills 4-6 and the conventional coated end mills 4-6,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm, as well as mass%, Ti-3.02% Al-2.53% V Ti alloy plate,
Cutting speed: 75 m / min. ,
Groove depth (cut): 4 mm
Table feed: 300mm / min,
With respect to the dry high-speed grooving test of Ti alloy under the conditions (normal cutting speed is 35 m / min.), The present coated end mills 7 and 8 and the conventional coated end mills 7 and 8,
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm, and Mass%, Ni-18.7% Cr-14.3% Co-4.51% Mo-2.53% Ti-1. A plate of Ni alloy having a composition of 98% Fe-1.18% Al-0.74% Mn-0.41% Si,
Cutting speed: 40 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 150 mm / min,
The Ni alloy dry high-speed grooving test (normal cutting speed is 20 m / min.) Was performed under the conditions of the above, and the flank wear width of the outer peripheral edge of the cutting edge was the service life of each grooving test. The cutting groove length up to 0.1 mm as a standard was measured. The measurement results are shown in Tables 8 and 9, respectively.

The diameter prepared in Example 2 of 8 mm (for substrates C-1 through C-3 form), 13 mm (for substrates C-4~C-6 form), and 26 mm (base C-7, C-8 form with three round bar sintered body use), from the three round bar sintered at grinding, diameter × length of the groove forming portions respectively 4 mm × 13 mm (base D-1 to D -3), 8mm × 22mm (base D-4~D-6), and dimensions of 16 mm × 45 mm (base D-7, D-8) , and both with a two-blade shape of the twist angle of 30 degrees Substrates (drills) D-1 to D-8 made of WC-base cemented carbide were produced.

Next, the cutting edges of these substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then mounted on the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the lower layer composed of a (Ti, Al, B) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 10, and the same layer thickness direction In accordance with the present invention, the upper layer composed of alternating layers of the thin layer A and the thin layer B having the target composition shown in Table 10 and a single target layer thickness is formed by vapor deposition with the overall target layer thickness shown in Table 10 as well. The surface-coated cermet drills according to the present invention (hereinafter referred to as the present invention-coated drills ) 1 to 8 as coated cermet tools were produced, respectively.

For comparison purposes, the surfaces of the substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and the arc ion plate shown in FIG. A hard coating layer comprising a (Ti, Al, B) N layer having a single phase structure with the target composition and target layer thickness shown in Table 11 under the same conditions as in Example 1 above. The conventional surface-covered cermet drills (hereinafter referred to as conventional coated drills ) 1 to 8 as conventional coated cermet tools were produced respectively.

Next, of the present invention coated drills 1 to 8 and the conventional coated drills 1 to 8, the present invention coated drills 1 to 3 and the conventional coated drills 1 to 3 are:
Work material-plane: 100 mm × 250, thickness: 50 mm, and a Ti alloy plate material having a composition of Ti-3.02% Al-2.53% V, and mass%,
Cutting speed: 40 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 6mm,
With regard to the Ti alloy wet high speed drilling cutting test under the conditions (normal cutting speed is 20 m / min.), The present invention coated drills 4-6 and the conventional coated drills 4-6,
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm, and Mass%, Ni-18.7% Cr-14.3% Co-4.51% Mo-2.53% Ti-1. A plate of Ni alloy having a composition of 98% Fe-1.18% Al-0.74% Mn-0.41% Si,
Cutting speed: 45 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 15mm,
With regard to the Ni alloy wet high speed drilling cutting test under the conditions (normal cutting speed is 25 m / min.), The present invention coated drills 7 and 8 and the conventional coated drills 7 and 8,
Work Material-Plane: 100 mm × 250 mm, Thickness: 50 mm in Dimensions and Mass%, Co-20.3% Cr-14.8% W-10. 1% Ni-1.45% Mn-0. A plate material of Co alloy having a composition of 95% Si-1.04% Fe-0.12% C;
Cutting speed: 50 m / min. ,
Feed: 0.25mm / rev,
Hole depth: 30mm,
Wet high-speed drilling test (normal cutting speed is 30 m / min.) Of Co alloy under the conditions of each of the above, and any wet high-speed drilling test (using water-soluble cutting oil) The number of drilling processes until the flank wear width reached 0.3 mm was measured. The measurement results are shown in Tables 10 and 11, respectively.

Hard coating layer made of (Ti, Al, B) N of the present coated chips 1-16, the present coated end mills 1-8, and the present coated drills 1-8 as the present coated cermet tool obtained as a result. thin layer a and the thin layer B of upper layer constituting the further composition of the lower layer, as well as traditional coatings chip 1 to 16 as a conventional coated cermet tool, the conventional coating end mills 1-8, and conventional coated drill 1-8 When the composition of the hard coating layer made of (Ti, Al, B) N was measured by energy dispersive X-ray analysis using a transmission electron microscope, each showed substantially the same composition as the target composition. .

  Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a transmission electron microscope, all showed the same average value (average value of five locations) as the target layer thickness.

From the results shown in Tables 3 to 11, each of the coated cermet tools of the present invention has an upper layer in which the hard coating layer has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm. The thin layer A and the thin layer B are composed of (Ti, Al, B) N each having a different composition, and the lower layer is excellent in high temperature hardness. In addition, the upper layer has excellent thermal conductivity, and as a result, the hard coating layer has these excellent characteristics, such as Ni alloy or Co alloy with high heat generation, Ti alloy, etc. Even in high-speed cutting of heat-resistant alloys, the hard coating layer exhibits excellent heat removal effect due to the upper layer, and exhibits excellent wear resistance without the occurrence of thermoplastic deformation that causes uneven wear on the cutting edge. In contrast, a single hard coating layer Structure (Ti, Al, B) conventional coated cermet tool composed of N layers, in particular thermal plastic deformation is generated in the cutting edge due to thermal conductivity insufficient hard layer, this by wear form uneven wear form It is clear that the wear progresses faster and reaches the service life in a relatively short time.

As described above, the coated cermet tool of the present invention is not only for cutting under normal cutting conditions such as various types of steel and cast iron, but particularly for high heat of heat-resistant alloys such as Ni alloys, Co alloys, and Ti alloys. Because it exhibits excellent wear resistance even during high-speed cutting that involves generation and exhibits excellent cutting performance over a long period of time, it has improved the performance of cutting equipment, and reduced labor and energy in cutting. In addition, it is possible to sufficiently satisfy the cost reduction.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated cermet tool is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of a normal arc ion plating apparatus.

Claims (1)

On the surface of the cermet substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(A) Both are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al, and B (boron), the upper layer being an average layer of 0.5 to 1.5 μm, and the lower layer being an average layer of 2 to 6 μm Each has a thickness,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: [Ti _{1− (E + F)} Al _E B _F ] N (wherein E is 0.01 to 0.10 and F is 0.15 to 0.35 in atomic ratio) A composite nitride layer of Al and B;
The thin layer B is
Ti satisfying the composition formula: [Ti _{1− (M + N)} Al _M B _N ] N (wherein M is 0.25 to 0.40 and N is 0.01 to 0.10 in atomic ratio) A composite nitride layer of Al and B,
(C) the lower layer has a single phase structure;
Ti satisfying the composition formula: [Ti _{1− (X + Y)} Al _X B _Y ] N (wherein X is 0.50 to 0.60 and Y is 0.01 to 0.10 in atomic ratio) A composite nitride layer of Al and B;
A surface-coated cermet cutting tool that exhibits excellent wear resistance in high-speed cutting of heat-resistant alloys, formed by vapor-depositing a hard coating layer made of

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