JP2005246509A - Cutting tool made of surface coated cermet with hard coating layer exhibiting excellent wear resistance in high-speed heavy cutting condition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cermet with a hard coating layer exhibiting excellent wear resistance in high-speed heavy cutting conditions. <P>SOLUTION: The cutting tool made of surface coated cermet is formed by physical vapor deposition of the hard coating layer comprising a compound nitride layer of Al (aluminum), Ti (tatanium) and B (boron), in the average layer thickness of 1-15 μm. In the hard coating layer, (a) boron nitride particles are dispersedly distributed in a solid solution base material composed of a compound nitride of Al and Ti, and the boron nitride particles have specific content ratio structure, and (b) the solid solution base material in (a) has a component concentration distribution structure wherein Al maximum content points and Ti maximum content points exist in alternate repetition at predetermined spaces along a layer thickness direction and the content rates of Al and Ti continuously change between both points, and the Al maximum content point and Ti maximum content point satisfy specific composition formulas, and further the spacing of the adjacent Al maximum content points and Ti maximum content points is 0.01-0.1 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  This invention has a high temperature hardness, heat resistance, and high strength with a hard coating layer. Therefore, cutting of various types of steel and cast iron, especially at high speed with high heat generation and high mechanical impact. A surface-coated cermet cutting tool (hereinafter referred to as a coated cermet tool) that exhibits excellent wear resistance without the occurrence of chipping (microchips) in the hard coating layer when performed under heavy cutting conditions such as high cutting and high feed. )).

  Generally, for coated cermet tools, drills used for slow-away inserts that are detachably attached to the tip of a bite for turning and planing of various steel and cast iron, drills for drilling, etc. And miniature drills, as well as solid type end mills used for chamfering, grooving, shoulder processing, etc. Also, the throwaway tip is detachably attached and the throw is performed in the same manner as the solid type endmill. Way end mill tools are known.

Further, as a coated cermet tool, a composition formula: (Ti ₁₋ ) is formed on the surface of a cermet base composed of a tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet. _{(E + F) Al E B} F) N ( provided that an atomic ratio, E is 0.40 to 0.60, F and Ti (titanium) which satisfies showing the 0.001 to 0.05) Al ( There is known a coated cermet tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride of aluminum and boron (hereinafter referred to as (Ti, Al, B) N) with a layer thickness of 1 to 15 μm. And the (Ti, Al, B) N layer, which is a hard coating layer of the coated cermet tool, has high-temperature hardness and heat resistance due to Al as a constituent component, and strength due to the Ti, and further with the same B. Effect of improving high temperature hardness of steel Te, is also known to exhibit excellent cutting performance when using this continuous cutting or intermittent cutting of various steels and cast iron.

Furthermore, the above-mentioned coated cermet tool, for example, the above-mentioned cermet substrate is loaded into an arc ion plating apparatus which is a kind of physical vapor deposition apparatus schematically shown in FIG. With the inside of the apparatus heated to a temperature of 400 to 500 ° C., current: 80 to 150 A, voltage between the anode electrode and the cathode electrode (evaporation source) in which a Ti—Al—B alloy having a predetermined composition is set : Arc discharge is generated under the condition of -20 to -30V, and simultaneously nitrogen gas is introduced into the apparatus as a reaction gas to make a reaction atmosphere of 1 to 10 Pa. On the other hand, the cermet substrate has a pressure of -30 to -150V. 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 cermet substrate under the condition that a bias voltage is applied. It has been.
JP-A-4-26756

  In recent years, there has been a remarkable increase in performance of cutting devices. On the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting processing. Although there is a tendency to require cutting under heavy cutting conditions such as high feed, there is no problem with the above-mentioned conventional coated cermet tool when it is used under normal cutting conditions. Is performed at high speed and under heavy cutting conditions such as high cutting with high mechanical impact and high feed, the high temperature hardness and heat resistance of the hard coating layer is insufficient and the strength is insufficient. Furthermore, since the progress of wear of the hard coating layer is further promoted and chipping is likely to occur, the service life is reached in a relatively short time.

In view of the above, the present inventors configured the above-described conventional coated cermet tool in order to develop a coated cermet tool exhibiting excellent wear resistance with a hard coating layer particularly under high-speed heavy cutting conditions. As a result of conducting research, focusing on the hard coating layer
(A) The (Ti, Al, B) N layer constituting the conventional coated cermet tool formed using the arc ion plating apparatus shown in FIG. 2 is substantially uniform over the entire layer thickness. An arc ion plating apparatus having a composition and thus having a uniform high-temperature hardness, heat resistance, and strength, but having a structure shown, for example, in a schematic plan view in FIG. 1A and a schematic front view in FIG. That is, a rotating table for mounting a cermet substrate is provided in the center of the apparatus, the Al-Ti-B alloy having a relatively high Al content is sandwiched between the rotating tables, and a Ti content is relatively disposed on the other side. Using an arc ion plating apparatus in which a high Ti—Al—B alloy is disposed as a cathode electrode (evaporation source), a position spaced apart from the central axis of the apparatus on the rotary table by a predetermined distance in the radial direction. A purpose of mounting a plurality of cermet bases in a ring shape along the outer periphery of the table, rotating the rotary table with the atmosphere inside the apparatus as a nitrogen atmosphere in this state, and making the thickness of the hard coating layer formed by vapor deposition uniform While the cermet substrate itself rotates, the bias voltage applied to the cermet substrate is compared with the bias voltage applied at the time of forming the conventional (Ti, Al, B) N layer, that is, -30 to -150V. A relatively low condition of −300 to −450 V (the conditions other than the bias voltage applied to the cermet substrate are the same as the above general conditions), and between the cathode electrode (evaporation source) on both sides and the anode electrode An arc discharge is generated to form a composite nitride [hereinafter referred to as (Al-Ti, B) N] layer of Al, Ti, and B on the surface of the cermet substrate. In the resulting (Al—Ti, B) N layer, application of a low voltage (−300 to −450 V bias voltage) to the cermet substrate causes the Al—Ti—B alloy and Ti— of the cathode electrode to be applied. The B component contained in the Al—B alloy uniquely forms boron nitride (hereinafter referred to as BN), which becomes fine particles and is a composite nitride of Al and Ti [hereinafter referred to as (Al, Ti) N]. The cermet substrate arranged in a ring shape on the rotary table is a relatively high Al content Al- on the one side. At the point closest to the cathode electrode (evaporation source) of the Ti—B alloy, the highest Al content point is formed in the (Al, Ti) N solid solution substrate, and the cermet substrate is relatively positioned on the other side. Ti included At the point of closest approach to the cathode electrode of a high amount of Ti-Al-B alloy, the highest Ti content point is formed in the solid solution substrate. As a result, the rotation of the rotary table causes the solid solution substrate to have a layer thickness direction. Accordingly, the Al highest content point and the Ti highest content point appear alternately and repeatedly at a predetermined interval, and the Al and Ti content from the Al highest content point to the Ti highest content point and from the Ti highest content point to the Al highest content point. A component concentration distribution structure in which the content ratio continuously changes is formed.

(B) In the formation of the (Al—Ti, B) N layer in which the solid solution substrate of (a) above has a repetitively continuously changing component concentration distribution structure, Al—Ti which is a cathode electrode (evaporation source) on one side opposed to each other Ti-Al-B, which is a cathode electrode (evaporation source) on the other side, with the Al content in the -B alloy relatively higher than the Al content in the conventional Ti-Al-B alloy The Al content in the alloy is relatively lower than the Al content of the conventional Ti-Al-B alloy, and the B content of the alloy constituting the cathode electrode is also taken into consideration, and the cermet substrate Controls the rotation speed of the rotary table
In the (Al, Ti) N solid solution substrate, the BN fine particles are present in a proportion of 0.001 to 0.05 in terms of the atomic ratio to the total amount of Al and Ti components, indicated by the content ratio of the B component. ,
And, the Al highest content point, the composition _{formula: (Al 1-X Ti X} ) N ( provided that an atomic ratio, X is shows the 0.05 to 0.25),
The highest Ti content point is the composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.05 to 0.25 in atomic ratio),
And the interval in the thickness direction of the adjacent Al highest content point and Ti highest content point adjacent to each other is 0.01 to 0.1 μm,
In the Al highest content point portion, the Al content rate is relatively higher than that of the conventional (Ti, Al, B) N layer, so that it exhibits higher temperature hardness and heat resistance, while the Ti content is higher. In the highest content point portion, since the Ti content is relatively higher than that of the conventional (Ti, Al, B) N layer, it has a higher strength, and these Al highest content point and Ti highest content point. The distance between the layers is extremely small, and in combination with the presence of extremely hard BN fine particles that are uniformly distributed in the solid solution base of (Al, Ti) N, a high strength is maintained as a characteristic of the entire layer. Therefore, the coated cermet tool composed of the (Al-Ti, B) N layer, which has a structure with a hard coating layer, has excellent high-temperature hardness and heat resistance, and is capable of cutting various types of steel and cast iron. Especially high heat generation and With a high mechanical shock, high speed when conducted in heavy cutting conditions even without the occurrence of chipping in the hard coating layer, to become to exert excellent wear resistance.
The research results shown in (a) and (b) above were obtained.

The present invention has been made based on the above research results. A hard coating layer made of an (Al—Ti, B) N layer is physically deposited on the surface of a cermet substrate with a layer thickness of 1 to 15 μm. In the coated cermet tool, the hard coating layer,
(A) When the BN fine particles are dispersed and distributed on the solid solution substrate composed of (Al, Ti) N, and the content ratio of the BN fine particles is indicated by the content ratio of the B component, the total amount of the Al and Ti components Having a structure of 0.001-0.05 in atomic ratio
(B) Further, in the solid solution substrate of the above (a), the Al highest content point and the Ti highest content point are alternately present at predetermined intervals along the layer thickness direction, and from the Al highest content point The Ti highest content point, having a component concentration distribution structure in which the content ratios of Al and Ti continuously change from the Ti highest content point to the Al highest content point, respectively,
The Al highest content point is the composition formula: (Al _1-X Ti _X ) N (however, in atomic ratio, X represents 0.05 to 0.25),
The highest Ti content point is the composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.05 to 0.25 in atomic ratio),
And the interval between the Al highest content point and the Ti highest content point adjacent to each other is 0.01 to 0.1 μm.
This is characterized by a coated cermet tool that exhibits excellent wear resistance under a high-speed heavy cutting condition.

Next, in the coated cermet tool of the present invention, the reason why the configuration of the hard coating layer constituting the tool is limited as described above will be described.
(A) Content ratio of BN fine particles dispersed and distributed in the solid solution substrate BN fine particles are extremely hard and distributed and distributed in the solid solution substrate to significantly improve the high-temperature hardness of the layer itself, thereby contributing to the improvement of the wear resistance of the hard coating layer. However, the content ratio is converted into the content ratio of the B component, and the atomic ratio of the total amount of the Al and Ti components is less than 0.001 (in this case, the cathode electrode of the arc ion plating apparatus) , The B content of both the oppositely arranged alloys is also less than 0.001), the dispersion ratio of the BN fine particles is too small to obtain the desired high-temperature hardness improvement effect, while the content ratio is the same. If it exceeds 0.05 (the B content of both the oppositely arranged alloys that are the cathode electrodes also exceeds 0.05), the B component will be contained in the solid solution substrate, and the strength of the hard coating layer will rapidly increase. Decline Since the chipping is likely to occur in the cutting edge part, the content ratio is converted into the content ratio of the B component, and the atomic ratio occupying the total amount of the Al and Ti components is determined to be 0.001 to 0.05. It was.

(B) The composition of the highest Al content point of the solid solution substrate The Al component at the highest Al content point of (Al, Ti) N constituting the solid solution substrate of the hard coating layer improves the high temperature hardness and heat resistance. There is an effect of improving the strength, and therefore, the higher the content ratio of the Al component, the higher the high temperature hardness and heat resistance, and the more suitable for high speed cutting with high heat generation, the X value indicating the ratio of Ti is If the ratio (atomic ratio) to the total amount with Al is less than 0.05, the ratio of Al becomes relatively large, and even if the highest Ti content point having high strength exists adjacently, the layer itself As a result, chipping is likely to occur. On the other hand, when the X value indicating the Ti component ratio exceeds 0.25, the Al ratio is relatively reduced, so that the high temperature hard And avoid lowering heat resistance However, since this causes the acceleration of wear, the X value was set to 0.05 to 0.25.

(C) Composition of the highest Ti content point of the solid solution substrate As described above, the highest Al content point of the solid solution substrate is excellent in high-temperature hardness and heat resistance, but on the other hand, it is inferior in strength. In order to compensate for the strength deficiency of Ti, the Ti content is high, thereby alternately interposing in the thickness direction the Ti highest content points that have high strength. Therefore, the Y value indicating the Al content is Ti When the ratio (atomic ratio) in the total amount exceeds 0.25, the ratio of Al becomes relatively large and the desired excellent strength cannot be ensured, while the same Y value is the same. If it is less than 0.05, the proportion of Ti is relatively increased, and the high temperature hardness and heat resistance at the highest Ti content point are drastically reduced, which causes wear acceleration. It was set as 05-0.25.

(C) Interval between the highest Al content point and the highest Ti content point of the solid solution substrate If the distance is less than 0.01 μm, it is difficult to clearly form each point with the above composition. The desired high strength, high temperature hardness and heat resistance cannot be secured, and if the distance exceeds 0.1 μm, each point has a defect, that is, if the Al highest content point is insufficient strength, the highest Ti content If it is a point, high-temperature hardness and insufficient heat resistance will appear locally in the layer, which may cause chipping on the cutting edge and promote wear progress. .01 to 0.1 μm.

(D) Layer thickness of hard coating layer If the layer thickness is less than 1 μm, the desired wear resistance cannot be ensured. On the other hand, if the layer thickness exceeds 15 μm, chipping tends to occur. The layer thickness was determined to be 1-15 μm.

  The coated cermet tool of the present invention can be used for cutting various steels and cast irons at high speed conditions with high temperature generation and heavy cutting conditions such as high cutting and high feed with high mechanical impact. The hard coating layer can exhibit excellent wear resistance without occurrence of chipping.

  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, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, and Co powder, all having an average particle diameter of 1 to 3 μm, were prepared. And then wet-mixed with a ball mill for 72 hours, dried, and press-molded into a green compact at a pressure of 100 MPa. The green compact was vacuumed at 6 Pa at a temperature of 1400 ° C. for 1 hour. The sintered cermet bases A1 to A10 made of WC-based cemented carbide having ISO standard / CNMG120408 chip shape by performing honing of R: 0.03 on the cutting edge portion after sintering under holding conditions. Formed.

In addition, as raw material powders, TiCN (mass ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder, all having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and 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 pressed into a compact at a pressure of 100 MPa. The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to obtain ISO standard / CNMG120408. The cermet bases B1 to B6 made of TiCN cermet having the following chip shape were formed.

  Next, each of the cermet substrates A1 to A10 and B1 to B6 is ultrasonically cleaned in acetone and dried, and then the cermet bases A1 to A10 and B1 to B6 have a radius from the central axis on the rotary table in the arc ion plating apparatus shown in FIG. A solid solution having a component composition shown in Table 3 as a cathode electrode (evaporation source) on one side in a combination shown in Table 3 and mounted in a ring shape along the outer periphery of the table at a predetermined distance in the direction Ti-Al-B alloy for forming the highest Ti content point of the substrate, Al-Ti- for forming the highest Al content point of the solid solution substrate having the composition shown in Table 3 as the cathode electrode (evaporation source) on the other side The B alloy is placed opposite to the rotary table, and the bombard cleaning metal Ti is also mounted. First, the inside of the apparatus is evacuated and kept at a vacuum of 0.5 Pa or less. After heating the inside of the apparatus to 500 ° C., a DC bias voltage of −1000 V is applied to the cermet substrate that rotates while rotating on the rotary table, and between the metal Ti and the anode electrode of the cathode electrode, Arc discharge is generated under the conditions of voltage: 25 V, current: 100 A, and the surface of the cermet substrate is cleaned by Ti bombardment. Then, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 2 Pa. A DC bias voltage of −400 V is applied to the cermet substrate that rotates while rotating, and each cathode electrode (Ti-Al—B alloy for forming the highest Ti content point of the solid solution substrate and for forming the highest Al content point) Arc discharge is generated between the Al-Ti-B alloy) and the anode electrode under the conditions of voltage: 25V and current: 100A. Therefore, BN fine particles are dispersed and distributed on the surface of the cermet substrate at a ratio shown in Table 4 on the solid solution base of (Al, Ti) N as measured by an Auger spectroscopic analyzer and an X-ray photoelectron spectroscope. Along the thickness direction, Ti solid content points and Al highest content points having the composition shown in Table 4 are alternately and repeatedly present at intervals shown in Table 4 in the solid solution substrate, It has a component concentration distribution structure in which the content ratios of Al and Ti continuously change from the content point to the Ti highest content point, from the Ti highest content point to the Al highest content point, and the layer thicknesses shown in Table 4 are also shown in Table 4 By depositing the hard coating layer, the surface-coated cermet throwaway tip (hereinafter referred to as the present invention-coated tip) 1 to 16 as the present invention-coated cermet tool is prepared. Each was produced.

  For comparison purposes, these cermet substrates A1 to A10 and B1 to B6 were ultrasonically cleaned in acetone and dried, and each was charged into a normal arc ion plating apparatus shown in FIG. Equipped with Ti-Al-B alloy with various component composition as cathode electrode (evaporation source), and also with metallic Ti for bombard cleaning, first evacuates the apparatus and keeps it at a vacuum of 0.5 Pa or less However, after heating the inside of the apparatus to 500 ° C. with a heater, a DC bias voltage of −1000 V was applied to the cermet substrate, and the voltage: 25 V, current: between the metal Ti of the cathode electrode and the anode electrode. An arc discharge is generated under the condition of 100 A, and the surface of the cermet substrate is cleaned by Ti bombardment. Then, nitrogen gas is introduced into the apparatus as a reactive gas, a direct-current bias voltage of −100 V (−400 V in the case of forming the hard coating layer of the present invention-coated chips 1 to 16) is applied to the cermet substrate, and the Ti—Al—B alloy of the cathode electrode is formed. Arc discharge was generated between the anode and the anode electrode under the conditions of voltage: 25V, current: 100A, and the surface of each of the cermet substrates A1 to A10 and B1 to B6 was measured by an Auger spectrometer. 5 and has substantially no composition change along the layer thickness direction, and the presence of BN fine particles is not observed even by measurement with an X-ray photoelectron spectrometer (Ti, Al, B). ) By depositing a hard coating layer consisting of N layers, a conventional surface-coated cermet throwaway tip (hereinafter referred to as a conventional coated cermet tool) Chip and refers) 1-16 were prepared, respectively.

Next, in the state where all the above-mentioned various coated chips are screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1 to 10 and the conventional coated chips 1 to 10 are as follows.
Work material: JIS / SNCM439 round direction bar with 4 equal intervals in the length direction,
Cutting speed: 320 m / min. ,
Cutting depth: 4.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
A dry interrupted high-speed high-cutting cutting test of alloy steel under the conditions (normal cutting speed is 200 m / min, the cutting is 2.5 mm),
Work material: JIS / S50C round bar,
Cutting speed: 450 m / min. ,
Incision: 1.5mm,
Feed: 0.6 mm / rev. ,
Cutting time: 10 minutes,
Carbon steel dry continuous high-speed high-feed cutting test (normal cutting speed is 250 m / min., The same feed is 0.3 mm / rev.),
Work material: JIS / FC250 round bar,
Cutting speed: 450 m / min. ,
Cutting depth: 4.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 15 minutes,
The dry continuous high-speed, high-cutting cutting test of cast iron under the conditions (normal cutting speed is 250 m / min., The cutting is 2.5 mm).

Furthermore, for the present coated chips 11-16 and the conventional coated chips 11-16,
Work material: JIS · SCM435 lengthwise equally spaced four round grooved round bars,
Cutting speed: 350 m / min. ,
Incision: 4mm,
Feed: 0.4 mm / rev. ,
Cutting time: 5 minutes
A dry interrupted high-speed high-cutting cutting test of alloy steel under the conditions (normal cutting speed is 200 m / min, the cutting is 2 mm),
Work material: JIS / S55C round bar,
Cutting speed: 400 m / min. ,
Cutting depth: 2mm,
Feed: 0.7 mm / rev. ,
Cutting time: 10 minutes,
Carbon steel dry continuous high-speed high-feed cutting test (normal cutting speed is 200 m / min., The same feed is 0.3 mm / rev.),
Work material: JIS / FC300 round bar,
Cutting speed: 500 m / min. ,
Cutting depth: 5mm,
Feed: 0.4 mm / rev. ,
Cutting time: 15 minutes,
The dry continuous high-speed, high-cutting cutting test of cast iron under the conditions (normal cutting speed is 250 m / min., The cutting is 2 mm), 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 (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 7, further added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then shaped into a predetermined shape at a pressure of 100 MPa. Various 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. For 1 hour and then sintering under furnace cooling conditions Three types of cermet substrate-forming round bar sintered bodies having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three types of round bar sintered bodies were subjected to grinding and combined in the combinations shown in Table 7 A cermet substrate (end mill) C- having a four-blade square shape with a diameter × length of the cutting edge portion of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and a twist angle of 30 degrees. 1 to C-8 were produced.

  Then, these cermet 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. In the combination shown, as the cathode electrode (evaporation source) on one side, the Ti-Al-B alloy for forming the highest Ti content point of the solid solution substrate having the component composition shown in Table 8, the cathode electrode (evaporation source) on the other side The Al-Ti-B alloy for forming the highest Al content point of the solid solution substrate having the component composition shown in Table 8 is also placed oppositely across the rotary table, and the same conditions as in Example 1 below. Then, on the surface of the cermet substrate, BN fine particles are dispersed and distributed at a ratio shown in Table 9 on the (Al, Ti) N solid solution substrate as measured by an Auger spectrometer and an X-ray photoelectron spectrometer. Along the layer thickness direction, Ti solid content points and Al highest content points having the component composition shown in Table 9 are alternately and repeatedly present at intervals shown in Table 9 in the solid solution substrate. It has a component concentration distribution structure in which the content ratios of Al and Ti continuously change from the highest Al content point to the highest Ti content point and from the highest Ti content point to the highest Al content point, which are also shown in Table 9. The surface-coated cermet end mills (hereinafter referred to as the present invention-coated end mills) 1 to 8 as the present invention-coated cermet tools were produced by depositing a hard coating layer having a layer thickness.

  For comparison purposes, the above cermet substrates (end mills) C-1 to C-8 are ultrasonically cleaned in acetone and dried, and the same is applied to the ordinary arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1 above, each component of the cermet substrate has the component composition and layer thickness shown in Table 10 as measured by an Auger spectroscopic analyzer, and in the layer thickness direction. A conventional coated cermet tool is deposited by vapor-depositing a hard coating layer composed of a (Ti, Al, B) N layer, which has substantially no composition change along the X-ray photoelectron spectrometer and no BN fine particles are observed. Conventional surface-coated cermet end mills (hereinafter referred to as conventional coated end mills) 1 to 8 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 dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCM435 plate material,
Cutting speed: 250 m / min. ,
Groove depth (cut): 1.5 mm,
Table feed: 1000 mm / min,
Test of dry high-speed, high-feed grooving of alloy steel under normal conditions (normal cutting speed is 150 m / min., Table feed is 500 mm / min), coated end mills 4 to 6 of the present invention and conventional coated end mills 4 to 6 Is
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / S45C plate,
Cutting speed: 350 m / min. ,
Groove depth (cut): 8 mm,
Table feed: 1200mm / min,
Carbon steel dry high-speed high-cut groove cutting test under normal conditions (normal cutting speed is 200 m / min., The groove depth is 4 mm), the present invention coated end mills 7 and 8 and the conventional coated end mills 7 and 8 ,
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 220 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 350 mm / min,
A dry high-speed, high-feed groove cutting test (normal cutting speed is 150 m / min. And the table feed is 200 mm / min) is performed on each of the above conditions. The cutting groove length was measured until the flank wear width of the blade reached 0.1 mm, which is a guide for the service life. The measurement results are shown in Tables 9 and 10, respectively.

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

  Next, the cutting blades of these cermet substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. The Ti-Al-B alloy for forming the highest Ti content point of the solid solution substrate having the component composition shown in Table 11 as the cathode electrode (evaporation source) on one side in the combination shown in Table 11 As a cathode electrode (evaporation source) on the side, an Al—Ti—B alloy for forming the highest Al content point of a solid solution substrate having the component composition shown in Table 11 is also placed oppositely across the rotary table. Under the same conditions as in Example 1, BN fine particles were found on the surface of the cermet substrate on the (Al, Ti) N solid solution substrate as measured by an Auger spectroscopic analyzer and an X-ray photoelectron spectroscope. In the same manner, Table 12 shows the highest Ti content points and the highest Al content points having the component composition shown in Table 12 along the layer thickness direction. It has a component concentration distribution structure that repeatedly exists at intervals, and in which the content ratio of Al and Ti continuously changes from the highest Al content point to the highest Ti content point and from the highest Ti content point to the highest Al content point. Similarly, by depositing a hard coating layer having a layer thickness shown in Table 12, the surface-coated cermet drills (hereinafter referred to as the present invention-coated drills) 1 to 8 as the present invention-coated cermet tools are produced. did.

  In addition, for comparison purposes, the cutting blades of the cermet substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried. In the same conditions as in Example 1 above, each surface of the cermet substrate has the component composition and the layer thickness shown in Table 13 as measured by an Auger spectrometer. In addition, a hard coating layer composed of a (Ti, Al, B) N layer is deposited by which there is substantially no change in composition along the layer thickness direction and the presence of BN fine particles is not observed even by measurement with an X-ray photoelectron spectrometer. Thus, conventional surface-coated cermet drills (hereinafter referred to as conventional coated carbide drills) 1 to 8 as conventional coated cermet tools were manufactured, 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 dimension: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 200 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 8mm,
Wet high-speed high-feed drilling test of alloy steel under the conditions (normal cutting speed is 100 m / min, the same feed is 0.1 mm / rev), the present invention coated drills 4 to 6 and the conventional coated drills 4 to 6 about,
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 180 m / min. ,
Feed: 0.35mm / rev,
Hole depth: 16mm,
Wet high-speed high-feed drilling test of tool steel under the conditions (normal cutting speed is 100 m / min, the same feed is 0.2 mm / rev), the present invention coated drills 7 and 8 and the conventional coated drills 7 and 8 about,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S55C plate material,
Cutting speed: 190 m / min. ,
Feed: 0.4mm / rev,
Hole depth: 32mm,
Wet high-speed high-feed drilling test (normal cutting speed is 100 m / min., The same feed is 0.2 mm / rev) under the above conditions, and each wet drilling test (water-soluble) (Using cutting oil) The number of drilling operations was measured until the flank wear width of the cutting edge surface reached 0.3 mm. The measurement results are shown in Tables 12 and 13, respectively.

From the results shown in Tables 3 to 13, the hard coating layer has a structure in which BN fine particles having extremely high high-temperature hardness are dispersed and distributed in the solid solution base of (Al, Ti) N, and the solid solution base has Along the layer thickness direction, the highest Ti content point having high strength and the highest Al content point having excellent high-temperature hardness and heat resistance are alternately present at predetermined intervals, and from the Al highest content point The present coated cermet tool having a component concentration distribution structure in which the Al and Ti contents continuously change from the highest Ti content point to the highest Al content point, respectively, includes various steels and cast irons. Even when cutting such as high-speed conditions with high temperature and heavy cutting conditions with high mechanical impact, such as high cutting and high feed, the hard coating layer is excellent without chipping. In the conventional coated cermet tool having a (Ti, Al, B) N layer in which the hard coating layer has substantially no composition change along the layer thickness direction while exhibiting wear, the above-mentioned high-speed heavy cutting is performed. Under the conditions, it is clear that the wear life is fast and chipping is likely to occur due to the high temperature hardness and heat resistance of the hard coating layer and insufficient strength, so that the service life can be reached in a relatively short time. is there.
As described above, the coated cermet tool according to the present invention can be used not only for cutting under normal conditions, but also for cutting various steels and cast irons under high-speed heavy cutting conditions with high heat generation and high mechanical impact. In this case, since chipping does not occur and excellent wear resistance is exhibited, it is possible to satisfactorily cope with labor saving and energy saving of cutting and cost reduction.

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

Claims (1)

A hard coating layer composed of a composite nitride layer of Al (aluminum), Ti (titanium), and B (boron) is formed on the surface of a cermet base composed of a tungsten carbide-based cemented carbide or a titanium carbonitride cermet. In the surface-coated cermet cutting tool formed by physical vapor deposition with a layer thickness of the hard coating layer,
(A) When boron nitride fine particles are dispersed and distributed in a solid solution base composed of a composite nitride of Al and Ti, and the content ratio of the boron nitride fine particles is expressed by the content ratio of the B component, It has a structure that is 0.001 to 0.05 in terms of atomic ratio to the total amount,
(B) Further, in the solid solution substrate of the above (a), the Al highest content point and the Ti highest content point are alternately present at predetermined intervals along the layer thickness direction, and from the Al highest content point The Ti highest content point, having a component concentration distribution structure in which the content ratios of Al and Ti continuously change from the Ti highest content point to the Al highest content point, respectively,
The Al highest content point is the composition formula: (Al _1-X Ti _X ) N (however, in atomic ratio, X represents 0.05 to 0.25),
The highest Ti content point is the composition formula: (Ti _1-Y Al _Y ) N (wherein Y represents 0.05 to 0.25 in atomic ratio),
And the interval between the Al highest content point and the Ti highest content point adjacent to each other is 0.01 to 0.1 μm,
A surface-coated cermet cutting tool that exhibits excellent wear resistance with a hard coating layer under high-speed heavy cutting conditions.

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