JP2005212049A - Surface-coated cermet cutting tool having hard coating layer exhibiting superior abrasion resistance under high speed heavy cutting condition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-coated cermet cutting tool having a hard coating layer exhibiting superior abrasion resistance under a high speed heavy cutting condition. <P>SOLUTION: This cutting tool is constituted by physically depositing the hard coating layer, having a structure of dispersively distributing an aluminum oxide phase at a rate of 1 to 15 area% on a basis material composed of composite nitride of Al, Ti and B (boron), allowing an Al maximum inclusion point and a Ti maximum inclusion point to alternately and repeatedly exist at a predetermined interval in the layer thickness direction in the basis material, satisfying a specific composition formula : (Al<SB>1-(E+Z)</SB>Ti<SB>E</SB>B<SB>Z</SB>)N on the Al maximum inclusion point and a specific composition formula : (Ti<SB>1-(X+Z)</SB>Al<SB>X</SB>B<SB>Z</SB>)N on the Ti maximum inclusion point, and being 0.01 to 0.1 μm in an interval between the adjacent Al maximum inclusion point and Ti maximum inclusion point, in the average layer thickness of 1 to 15 μm, on a surface of a cermet base body composed of tungsten carbide group cemented carbide or tungsten carbonitride-based cermet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention has excellent high temperature hardness and heat resistance with a hard coating layer, and also excellent high temperature strength. Therefore, cutting of various steels and cast irons, especially at high speed with high heat generation and high mechanical strength. Made of surface-coated cermet that provides excellent wear resistance over a long period of time, even when heavy cutting conditions such as high cutting with impact and high feed are performed, and the hard coating layer does not cause chipping (microchips). The present invention relates to a cutting tool (hereinafter referred to as a coated cermet tool).

Technical background

  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. _{(M + Z) Al M B} Z) N ( provided that an atomic ratio, M is 0.40 to 0.60, Z is Ti, Al and B to satisfy the showing the 0.01-0.10) (boron And a coated cermet tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride [hereinafter referred to as (Ti, Al, B) N] layer with an average layer thickness of 1 to 15 μm, and The (Ti, Al, B) N layer, which is a hard coating layer of a coated cermet tool, has high-temperature hardness and heat resistance due to Al as a constituent component, high-temperature strength due to the Ti, and one-step high-temperature hardness due to the same B. Combined with the improvement effect, this It is also known to exhibit excellent cutting performance when used in continuous cutting or interrupted cutting of cast iron.

  Further, the above-described coated cermet tool is used, for example, in which the above cermet substrate is loaded into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. An arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) in which a Ti—Al—B alloy having a predetermined composition is set, for example, at a current of 90 A, while being heated to a temperature of ° C. At the same time, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa. On the other hand, the cermet substrate is subjected to the above (Ti) on the surface of the cermet substrate under the condition that a bias voltage of, for example, −100 V is applied. , Al, B) It is also known to be produced by vapor-depositing a hard coating layer consisting of an N layer.

Japanese Patent No. 2793696

  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 under heavy cutting conditions such as high cutting and high feed with high mechanical impact at high speed, the high temperature hardness and heat resistance of the hard coating layer is insufficient, and the high temperature strength is also insufficient. Therefore, 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) For example, as a raw material powder, an Al—Ti—B alloy powder having a relatively high Al content, a Ti—Al—B alloy powder having a relatively high Ti content, and aluminum oxide (hereinafter referred to as Al ₂ O ₃₎ These raw material powders are blended at a predetermined blending ratio using a powder, mixed and then press-molded into a green compact. The green compact is subjected to normal conditions such as 500 to 600 ° C. in a vacuum atmosphere. Sintered at a predetermined temperature within the range of the above-mentioned conditions for a predetermined time, and an Al system having a structure in which an Al ₂ O ₃ phase is dispersed and contained in a base material of an Al—Ti—B alloy having a relatively high Al content An alloy sintered body and a Ti-based alloy sintered body having a structure in which an Al ₂ O ₃ phase is dispersed and contained in a base material of a Ti—Al—B alloy having a relatively high Ti content are formed. (A) is a schematic plan view and (b) is a schematic front view. In other words, using an arc ion plating apparatus having a structure in which a cermet substrate mounting rotary table is provided at the center of the apparatus, the Al-based alloy sintered body on one side and the above-mentioned Al-based alloy sintered body on the other side Ti-based alloy sintered body is placed opposite to each other as a cathode electrode (evaporation source), and a plurality of cermet substrates are ringed along the outer periphery of the table at a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. In this state, the atmosphere inside the apparatus is changed to a nitrogen atmosphere, the rotary table is rotated, and the cermet substrate itself is rotated for the purpose of uniformizing the thickness of the hard coating layer formed by vapor deposition. When an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode to form a hard coating layer on the surface of the cermet substrate, this Hard layer of fruits, complex nitrides of Al, Ti, and B [hereinafter, (Al / Ti, B) indicated by N] has a tissue Al ₂ O ₃ phase is dispersed distribution matrix consisting of, and, The (Ti, Al, B) N layer constituting the hard coating layer of the conventional coated cermet tool formed using the arc ion plating apparatus shown in FIG. 2 is substantially uniform over the entire layer thickness. In the (Al / Ti, B) N substrate, the cermet arranged in a ring shape on the rotary table has a uniform composition, and therefore has a uniform high temperature hardness and heat resistance, and a uniform high temperature strength. When the substrate is closest to the cathode electrode (evaporation source) of the Al alloy sintered body on one side, the highest Al content point is formed in the substrate, and the cermet substrate is the Ti on the other side. Cathode electrode of sintered alloy At the point of closest approach, the highest Ti content point is formed in the substrate, and the rotation of the rotary table causes the Al highest content point and the highest Ti content point to appear alternately and repeatedly along the layer thickness direction in the substrate. At the same time, it has a component concentration distribution structure in which the Al and Ti contents 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.

(B) In the base made of (Al / Ti, B) N having the repeated continuous change component concentration distribution structure of (a) above, the Al-based alloy sintered body that is the cathode electrode (evaporation source) on one side of the opposing arrangement The Al content of the Al—Ti—B alloy as the raw material powder is compared with the Al content of the Ti—Al—B alloy used as the cathode electrode (evaporation source) in the conventional (Ti, Al, B) N layer formation. Therefore, the Al content of the Ti—Al—B alloy, which is the raw material powder of the Ti-based alloy sintered body, which is the cathode electrode (evaporation source) on the other side, is set to the above-described conventional (Ti, Al , B) The rotational speed of the rotary table on which the cermet substrate is mounted while being relatively lower than the Al content of the Ti-Al-B alloy which is the cathode electrode (evaporation source) for forming the N layer. Control
The Al highest content point is the composition formula: (Al _{1- (E + Z)} Ti _E B _Z ) N (wherein E is 0.05 to 0.25, Z is 0.01 to 0.00 in terms of atomic ratio). 10),
The Ti maximum content point, composition _{formula: (Ti 1- (X + Z} ) Al X B Z) N ( provided that an atomic ratio, X is 0.05 to 0.25, Z is from 0.01 to 0. 10),
And the distance in the thickness direction between the adjacent Al highest content point and Ti highest content point adjacent to each other is set to 0.01 to 0.1 μm,
When the ratio of the Al ₂ O ₃ phase dispersed and distributed in the substrate is 1 to 15 area% by cross-sectional observation with an Auger spectroscopic analyzer, the Al highest content point portion in the substrate of the resulting hard coating layer Since the Al content is relatively higher than that of the conventional (Ti, Al, B) N layer, the high temperature hardness and heat resistance are further improved. Since the Ti content is relatively higher than that of the (Ti, Al, B) N layer, it has higher high-temperature strength and the distance between the Al highest content point and the Ti highest content point is extremely small. As a result, the entire substrate has excellent high-temperature hardness and heat resistance while maintaining high high-temperature strength, and the Al ₂ O ₃ phase dispersed and distributed in the substrate further increases the Since the thermal hardness and excellent thermal stability are ensured, the coated cermet tool formed by physical vapor deposition of such a hard coating layer is used for cutting various steels and cast iron, especially for high heat generation and high machinery. Even when performed under high-speed heavy cutting conditions with mechanical impact, the hard coating layer should exhibit excellent wear resistance without chipping.
The research results shown in (a) and (b) above were obtained.

The present invention has been made on the basis of the above research results. The surface of the cermet substrate, the base made of (Al / Ti, B) N, and the Al ₂ O ₃ phase observed by an Auger spectrometer. The hard coating layer having a structure distributed and distributed at a rate of 1 to 15 area% is physically vapor-deposited with an average layer thickness of 1 to 15 μm,
Further, in the substrate composed of (Al / Ti, B) N, the Al highest content point and the Ti highest content point are alternately present at predetermined intervals along the layer thickness direction, and the Al highest content From the point, the Ti highest content point, from the Ti highest content point to the Al highest content point has a component concentration distribution structure in which Al and Ti content each continuously change,
The Al highest content point is the composition formula: (Al _{1- (E + Z)} Ti _E B _Z ) N (wherein E is 0.05 to 0.25, Z is 0.01 to 0.00 in terms of atomic ratio). 10),
The Ti maximum content point, composition _{formula: (Ti 1- (X + Z} ) Al X B Z) N ( provided that an atomic ratio, X is 0.05 to 0.25, Z is from 0.01 to 0. 10),
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) Composition of the highest Al content point of the substrate The Al component of the highest Al content point in (Al / Ti, B) N, which is the substrate of the hard coating layer, improves the high temperature hardness and heat resistance, and the Ti component has a high temperature. The B component has the effect of further improving the high temperature hardness, and therefore, the higher the content ratio of the Al component and the B component, the higher the high temperature hardness and heat resistance, and high speed cutting with high heat generation. However, when the E value indicating the proportion of Ti is less than 0.05 in the proportion of the total amount of Al and B (atomic ratio), the proportion of Al is relatively large and high. Even if the highest Ti content point having high temperature strength is present adjacently, a decrease in the high temperature strength of the substrate itself is unavoidable. If it exceeds 25, A Since the ratio of l decreases, a decrease in high temperature hardness and heat resistance is inevitable, which causes the acceleration of wear, and the ratio of the Z value indicating the ratio of the B component to the total amount of Al and Ti (atomic ratio) ) Less than 0.01, the desired high-temperature hardness improvement effect cannot be obtained, and when the Z value exceeds 0.10, the high-temperature strength decreases, which causes chipping and the like. The E value was set to 0.05 to 0.25, and the Z value was set to 0.01 to 0.10.

(B) Composition of the highest Ti content point of the substrate As described above, the highest Al content point is excellent in high-temperature hardness and heat resistance, but on the other hand, it is inferior in high-temperature strength. In order to make up for the shortage, the Ti content is high, and thus the highest Ti content point that has high high-temperature strength is alternately interposed in the thickness direction. Therefore, the X value indicating the proportion of Al is Ti and If the ratio (atomic ratio) in the total amount of B exceeds 0.25, the ratio of Al becomes relatively large, and the desired excellent high-temperature strength cannot be secured, while the X value is the same. Similarly, 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 promotion. .05-0.25 In addition, the Z value indicating the ratio of the B component was determined to be 0.01 to 0.10 for the same reason as in the above Al maximum content point.

(C) Interval between the highest Al content point and the highest Ti content point of the substrate If the distance is less than 0.01 μm, it is difficult to form each point clearly with the above composition. High temperature strength, high temperature hardness and heat resistance can not be ensured, and if the distance exceeds 0.1 μm, each point has defects, that is, if Al is the highest content point, high temperature strength is insufficient, Ti is the highest 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) Al ₂ O ₃ phase ratio Al ₂ O ₃ phase dispersed distribution matrix imparts a much higher hot hardness and good thermal stability as a hard coating layer of the above, a companion to have with high fever The hard coating layer has an effect of exhibiting excellent wear resistance even at high speed cutting, but the Al ₂ O ₃ phase ratio in the hard coating layer is less than 1 area% by cross-sectional observation with an Auger spectrometer. In this case, the desired effect cannot be obtained in the above-mentioned operation. On the other hand, if the same ratio exceeds 15 area%, the excellent high-temperature strength provided by the base material suddenly decreases, so the hard coating layer of the Al ₂ O ₃ phase The ratio was determined as 1 to 15 area%.

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

The base material of the hard coating layer is repeatedly present in the layer thickness direction with the Al highest content point having excellent high temperature hardness and heat resistance and the Ti highest content point having excellent high temperature strength alternately at predetermined intervals. The Al concentration content has a component concentration distribution structure in which the Al and Ti contents continuously change from the highest Al content point to the highest Ti content point, from the highest Ti content point to the highest Al content point, and in the base. The coated cermet tool of the present invention having a structure in which Al ₂ O ₃ phase with excellent high-temperature hardness and thermal stability is dispersed and distributed is used for cutting various steels and cast iron under high-speed conditions accompanied by high-temperature generation. In addition, even when performed under heavy cutting conditions such as high cutting and high feed with high mechanical impact, the hard coating layer exhibits 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. Sintered under holding conditions, and after sintering, the cutting edge portion was subjected to honing of R: 0.03, and the cermet substrate A-1 made of WC-based cemented carbide having a chip shape of ISO standard CNMG120408 A-10 was formed.

In addition, as raw material powders, all are TiCN (weight ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder 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 B-1 to B-6 made of TiCN-based cermet having the following chip shape were formed.

Furthermore, as raw material powders, all of Al-Ti-B alloy powders of various compositions having a relatively high Al content and a relatively high Ti content, both having a predetermined average particle size in the range of 0.5 to 3 µm. Ti-Al-B alloy powders of various compositions with high composition, and further Al ₂ O ₃ powder, these raw material powders are blended into a predetermined composition, wet mixed for 72 hours with a ball mill, dried, and then at a pressure of 100 MPa. Press compacted into green compacts, and the green compacts were sintered in a 6 Pa vacuum at a predetermined temperature in the range of 500-600 ° C. for 1 hour, with various relatively high Al contents. An Al-based alloy sintered body having a structure in which an Al ₂ O ₃ phase is dispersed and contained at a predetermined ratio on an Al-Ti-B alloy substrate of composition, and Ti-Al of various compositions having a relatively high Ti content the ratio Al ₂ O ₃ phase is given into a green body of -B alloy Ti-based alloy sintered body having a dispersion containing tissue was formed (present invention for hard layer formation).
In addition, various Ti—Al—B alloys having different content ratios of Ti, Al, and B were also prepared as separate cathode electrodes for forming a conventional hard coating layer.

Next, each of the cermet substrates A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then in the arc ion plating apparatus shown in FIG. Ti-based alloy for forming the highest Ti content point as a cathode electrode (evaporation source) mounted on the outer periphery of the table at a predetermined distance in the radial direction from the central axis on the rotary table, as a cathode electrode (evaporation source) on one side As the sintered body, the cathode electrode (evaporation source) on the other side, the Al-based alloy sintered body for forming the highest Al content point is disposed opposite to the rotary table, and the metal Ti for bombard cleaning is also mounted. While the inside of the apparatus is evacuated and kept at a vacuum of 0.5 Pa or less, the inside of the apparatus is heated to 500 ° C. with a heater, and then is directly applied to a cermet substrate that rotates while rotating on the rotary table. A bias voltage is applied and a current of 100 A is passed between the metal Ti and the anode electrode of the cathode electrode to generate an arc discharge, thereby cleaning the surface of the cermet substrate by Ti bombardment, and then nitrogen as a reactive gas in the apparatus. A gas is introduced to form a reaction atmosphere of 2 Pa, a DC bias voltage of −100 V is applied to the cermet substrate that rotates while rotating on the rotary table, and each cathode electrode (Ti for forming the highest Ti content point) is applied. An arc discharge is generated by passing a current of 100 A between the sintered alloy and the Al-based alloy sintered body for forming the highest Al content point) and the anode electrode, so that the surface of the cermet substrate is formed in the layer thickness direction. Along with the target intervals shown in Tables 3 and 4, the highest Al content points and the highest Ti content points of the target compositions shown in Tables 3 and 4 are alternately shown. To the substrate having a component concentration distribution structure in which the Al and Ti contents continuously change from the Al highest content point to the Ti highest content point, from the Ti highest content point to the Al highest content point, respectively, while being repeatedly present. By coating a hard coating layer having a structure in which Al ₂ O ₃ phases are dispersed and contained at the target ratios shown in Tables 3 and 4 and also having the target layer thicknesses shown in Tables 3 and 4, the coating of the present invention is performed. The surface-covered cermet throwaway tips (hereinafter referred to as the present invention-coated tips) 1 to 16 as cermet tools were produced, respectively.

  For comparison purposes, these cermet substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, and each of the normal arc ions shown in FIG. It is inserted into the plating apparatus, a Ti—Al—B alloy having a predetermined composition is mounted as a cathode electrode (evaporation source), and further a bombard cleaning metal Ti is mounted. The inside of the apparatus was heated to 500 ° C. with a heater while maintaining a vacuum of .5 Pa or less, and then a −1000 V DC bias voltage was applied to the cermet substrate, and the cathode Ti between the metal Ti and the anode electrode An arc discharge is generated by supplying a current of 100 A, so that the surface of the cermet substrate is cleaned by Ti bombardment, and then nitrogen gas is introduced into the apparatus as a reaction gas so as to have a reaction atmosphere of 2 Pa. At the same time, a DC bias voltage of −100 V is applied to the cermet substrate, and a current of 100 A is caused to flow between the Ti—Al—B alloy of the cathode electrode and the anode electrode, thereby generating an arc discharge. Each surface of the substrates A-1 to A-10 and B-1 to B-6 has the target composition and target layer thickness shown in Table 5, and substantially changes in composition along the layer thickness direction. By depositing a hard coating layer consisting of no (Ti, Al, B) N layers, conventional surface coated cermet throwaway tips (hereinafter referred to as conventional coated tips) 1 to 16 as conventional coated cermet tools are manufactured. did.

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 / FC250 round bar,
Cutting speed: 240 m / min. ,
Cutting depth: 3.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
A dry continuous high-speed high-cut cutting test of cast iron under the conditions (normal cutting speed and cutting are 120 m / min. And 2.5 mm),
Work material: JIS · S45C lengthwise equal 4 round grooved round bars,
Cutting speed: 220 m / min. ,
Incision: 3mm,
Feed: 0.4 mm / rev. ,
Cutting time: 3 minutes
A carbon steel dry interrupted high-speed high-cut cutting test (normal cutting speed and cutting are 150 m / min. And 2 mm),
Work material: JIS / SKD61 round bar,
Cutting speed: 150 m / min. ,
Cutting depth: 1mm,
Feed: 0.5 mm / rev. ,
Cutting time: 8 minutes
The dry continuous high-speed, high-feed cutting test of the tool steel under the conditions (normal cutting speed and feed were 100 m / min. And 0.3 mm / rev.).

Furthermore, for the present coated chips 11-16 and the conventional coated chips 11-16,
Work material: JIS / SNCM439 round direction bar with 4 equal intervals in the length direction,
Cutting speed: 280 m / min. ,
Incision: 2.5mm,
Feed: 0.5 mm / rev. ,
Cutting time: 3 minutes
Dry interrupted high-speed high-feed cutting test of alloy steel under the conditions (normal cutting speed and feed are 150 m / min. And 0.2 mm / rev.),
Work material: JIS / SCM435 round bar,
Cutting speed: 300 m / min. ,
Incision: 3mm,
Feed: 0.4 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed high-cut cutting test of alloy steel under the conditions of (normal cutting speed and cutting is 250 m / min. And 1.5 mm),
Work material: JIS / SS400 round bar,
Cutting speed: 400 m / min. ,
Cutting depth: 2mm,
Feed: 0.45 mm / rev. ,
Cutting time: 15 minutes,
A continuous continuous high-speed, high-feed cutting test for structural steel under normal conditions (normal cutting speeds and feeds are 300 m / min. And 0.3 mm / rev.). The surface wear width was measured. 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 Prepare a powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C powder, and 1.8 μm Co powder. Each was blended in the blending composition shown in Table 7, further added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, then pressed into various compacts of a predetermined shape at a pressure of 100 MPa. The green compact is 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, held at this temperature for 1 hour, and then fired under furnace cooling conditions. Finally, the diameters are 8mm, 13mm, and 26 m, the three cermet substrate-forming round bar sintered bodies, and the above three kinds of round bar sintered bodies by grinding, in the combinations shown in Table 7, Cermet substrates (end mills) C-1 to C-8 each having 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 each having a twist angle of 30 degrees, respectively. Manufactured.

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. 1, the highest Al content point and the highest Ti content point of the target composition shown in Table 8 along the layer thickness direction are alternately present at the target interval shown in Table 8, and the Al The bases having the component concentration distribution structure in which the Al and Ti contents continuously change from the highest content point to the highest Ti content point and from the highest Ti content point to the highest Al content point are also shown in Table 8 have a tissue that Al ₂ O ₃ phase contained dispersed at a ratio, and also by depositing a hard coating layer of the target layer thicknesses shown in Table 8, the present invention the surface of the present invention coated cermet tool Covered cermet end mill (hereinafter, the present invention refers to the coating end mill) 1-8 were prepared, respectively.

  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. And having the target composition and target layer thickness shown in Table 9 under the same conditions as in Example 1, and substantially no composition change along the layer thickness direction (Ti, Al, B) By vapor-depositing a hard coating layer composed of an N layer, conventional surface-coated cermet end mills (hereinafter referred to as conventional coated end mills) 1 to 8 as conventional coated cermet tools were produced, respectively.

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 dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S50C plate material,
Cutting speed: 150 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 900 mm / min,
Carbon steel dry high-speed, high-feed groove cutting test under normal conditions (normal cutting speed and table feed are 100 m / min. And 500 mm / min), the coated end mills 4 to 6 and the conventional coated end mills 4 to 6 Is
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 90 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 200 mm / min,
The tool steel dry dry high-speed, high-groove grooving test (normal cutting speed and groove depth is 60 m / min. And 3.5 mm), the present invention coated end mills 7 and 8 and the conventional coated end mills 7 and 8 about,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 180 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 550 mm / min,
A dry high-speed, high-feed groove cutting test (normal cutting speed and table feed is 100 m / min. And 240 mm / min) is performed for 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 8 and 9, 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. In the same conditions as in Example 1 above, the highest Al content point and the highest Ti content point of the target composition shown in Table 10 along the layer thickness direction alternately at the target interval shown in Table 10 To the substrate having a component concentration distribution structure in which the Al and Ti contents continuously change from the Al highest content point to the Ti highest content point, from the Ti highest content point to the Al highest content point, respectively, while being repeatedly present. also has a tissue Al ₂ O ₃ phase contained dispersed at the target the proportions shown in Table 10, and also by depositing a hard coating layer of the target layer thicknesses shown in Table 10, the present invention coated Sir Tsu Applications This invention surface coating cermet drill as the tool (hereinafter, the present invention refers to the coating drills) 1-8 were prepared, respectively.

  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. And having the target composition and target layer thickness shown in Table 11 and substantially no composition change along the layer thickness direction under the same conditions as in Example 1 above. By vapor-depositing a hard coating layer composed of a (Ti, Al, B) N layer, conventional surface-coated cermet drills (hereinafter referred to as conventional coated drills) 1 to 8 as conventional coated cermet tools were produced.

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 / FCD450 plate material,
Cutting speed: 125 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 8mm,
Wet high-speed high-feed drilling test of ductile cast iron under the following conditions (normal cutting speed and feed are 75 m / min. And 0.14 mm / rev.), The present invention coated drills 4 to 6 and the conventional coated drill 4 to For 6,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / SS400 plate material,
Cutting speed: 200 m / min. ,
Feed: 0.32mm / rev,
Hole depth: 16mm,
Wet high-speed high-feed drilling test of structural steel under normal conditions (normal cutting speed and feed are 100 m / min. And 0.23 mm / rev.), Inventive coated drills 7 and 8 and conventional coated drill 7 , 8
Work material: Plane dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / S45C plate,
Cutting speed: 150 m / min. ,
Feed: 0.35mm / rev,
Hole depth: 32mm,
The carbon steel was subjected to a wet high-speed high-feed drilling test (normal cutting speed and feed were 80 m / min. And 0.27 mm / rev.), Respectively. The number of holes drilled until the flank wear width of the tip cutting edge surface reached 0.3 mm was also measured. The measurement results are shown in Tables 10 and 11, respectively.

As a result, the coated chips 1 to 16 of the present invention as the coated cermet tool of the present invention, the hard coated layers constituting the coated end mills 1 to 8 and the coated drills 1 to 8 of the present invention, and the conventional coated cermet tool For hard coating layers of conventional coated chips 1 to 16, conventional coated end mills 1 to 8, and conventional coated drills 1 to 8, the contents of Al, Ti, and B, and oxygen (O) are Auger along the thickness direction. As measured using a spectroscopic analyzer, in the hard coating layer of the coated cermet tool of the present invention, the base material is alternately repeated with the composition and interval between the highest Al content point and the highest Ti content point substantially the same as the target value. Al and Ti content 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. Is a continuously varying component concentration distribution structure, it was confirmed that further Al ₂ O ₃ phase dispersed distribution on the matrix at substantially the same rate and the target value, and the average layer thickness of the hard coating layer The value was substantially the same as the target layer thickness.
On the other hand, it is confirmed that the hard coating layer of the conventional coated cermet tool shows no composition change along the thickness direction, and shows a composition substantially the same as the target composition and an average layer thickness substantially the same as the target layer thickness. It was done.

From the results shown in Tables 3 to 11, the highest Al content point having excellent high temperature hardness and heat resistance and the highest Ti content point having excellent high temperature strength are repeatedly repeated at predetermined intervals in the layer thickness direction. In addition to the Al highest content point, the Ti highest content point, the Ti highest content point to the Al highest content point, and a substrate having a component concentration distribution structure in which the Al and Ti contents continuously change, respectively, _The coated cermet tool of the present invention formed by physical vapor deposition of a hard coating layer having a structure in which the ₂ O ₃ phase is distributed and distributed is high in high-speed conditions accompanied by high-temperature generation and high cutting performance of various steels and cast irons. Even when performed under heavy cutting conditions such as high cutting and high feed with mechanical impact, the hard coating layer exhibits excellent wear resistance without occurrence of chipping, whereas the hard coating layer is a layer. In a conventional coated cermet tool composed of a (Ti, Al, B) N layer that does not substantially change in composition along the direction, the high temperature hardness and insufficient heat resistance of the hard coating layer under the high-speed heavy cutting conditions, In addition, due to insufficient high-temperature strength, wear progresses quickly and chipping easily occurs, so that it is clear that the service life is reached in a relatively short time.
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)

Cross-section observation of aluminum oxide phase on Auger spectrophotometer on substrate made of composite nitride of Al, Ti and B (boron) on the surface of cermet substrate composed of tungsten carbide base cemented carbide or titanium carbonitride cermet The hard coating layer having a structure distributed and distributed at a rate of 1 to 15 area% is physically vapor-deposited with an average layer thickness of 1 to 15 μm,
Furthermore, the base composed of the composite nitride of Al, Ti, and B has an Al highest content point and a Ti highest content point alternately and repeatedly at predetermined intervals along the layer thickness direction. From the content point to the Ti highest content point, from the Ti highest content point to the Al highest content point and having a component concentration distribution structure in which the Al and Ti content continuously change, respectively,
The Al highest content point is the composition formula: (Al _{1- (E + Z)} Ti _E B _Z ) N (wherein E is 0.05 to 0.25, Z is 0.01 to 0.00 in terms of atomic ratio). 10),
The Ti maximum content point, composition _{formula: (Ti 1- (X + Z} ) Al X B Z) N ( provided that an atomic ratio, X is 0.05 to 0.25, Z is from 0.01 to 0. 10),
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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