JP2005288668A - Surface-coated cermet cutting tool that exhibits excellent chipping resistance in high-speed heavy cutting of difficult-to-cut materials. - Google Patents

Abstract

A surface-coated cermet cutting tool that exhibits excellent chipping resistance with a hard coating layer in high-speed heavy cutting of difficult-to-cut materials.
A surface-coated cermet cutting tool has a surface of a cermet base, a ZrO ₂ phase formed on a substrate made of (Ti-Al, B) N, having a cross-sectional analysis of 0.3 to 15% by area using an Auger spectrometer. The substrate composed of (Ti-Al, B) N having a structure distributed and distributed in a ratio is repeated alternately with a predetermined interval between the highest Al content point and the lowest Al content point along the layer thickness direction. And a component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, The hard coating layer is 0.5 in which the highest component content and the lowest content point satisfy a specific composition formula, and the distance between the adjacent highest Al content point and the lowest Al content point is 0.01 to 0.1 μm. Physical with an average layer thickness of ~ 15μm Wear and composed.
[Selection] Figure 1

Description

  In the present invention, the hard coating layer has excellent high-temperature strength, has high-temperature hardness and heat resistance, and also has excellent surface lubricity against chips, and therefore has extremely high viscosity, particularly stainless steel and mild steel, and When cutting difficult-to-cut materials, etc., where chips easily adhere to the cutting edge surface, at high speed with high heat generation and heavy cutting conditions such as high cutting with high mechanical impact and high feed The present invention also relates to a surface-coated cermet cutting tool (hereinafter referred to as a coated cermet tool) that exhibits excellent chipping resistance with a hard coating layer.

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: 0.01 to 0.10 satisfies the shown) Ti, Al and B (boron A coated cermet tool formed by physically vapor-depositing a hard coating layer composed of a composite nitride [hereinafter referred to as (Ti, Al, B) N] layer of 0.5) to 15 μm is known, The (Ti, Al, B) N layer, which is a hard coating layer of the coated cermet tool, has high-temperature strength and high-temperature hardness and heat resistance due to Ti, which is a constituent component. Combined with the improvement effect of hardness, this It is also known to exhibit excellent cutting performance when used for continuous cutting and intermittent cutting of various steels and 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 improvement in the performance of cutting devices. On the other hand, there has been a strong demand for labor saving and energy saving and further cost reduction for cutting. There is a strong demand for a coated cermet tool that exhibits excellent cutting performance even in cutting operations under heavy cutting conditions such as high feed, but the above-mentioned conventional coated cermet tools are used for cutting various steels and cast iron. There is no problem when using under normal cutting conditions, but cutting of difficult-to-cut materials such as stainless steel and mild steel, which are extremely viscous and the chips are likely to weld to the cutting edge surface, is accompanied by high heat generation. When cutting at high speeds and under heavy cutting conditions such as high cutting and high feed with high mechanical impact, the cutting edge part is due to insufficient high-temperature strength of the hard coating layer and high weldability to chips. Chipping easily (microcracks) occurs, at present, leading to a relatively short time service life.

In view of the above, the present inventors have to develop a coated cermet tool that exhibits excellent chipping resistance with a hard coating layer particularly in high-speed heavy cutting of difficult-to-cut materials such as stainless steel and mild steel from the above viewpoint. , As a result of conducting research, focusing on the hard coating layer that constitutes the above conventional coated cermet tool,
(A) As a raw material powder, for example, it has a composition corresponding to the composition of the Ti—Al—B alloy used as the cathode electrode (evaporation source) for forming the conventional (Ti, Al, B) N layer. Ti-Al-B alloy powder having a high Al content, Ti-Al-B alloy powder having a relatively low Al content compared to the Ti-Al-B alloy powder, and zirconium oxide (hereinafter referred to as ZrO). ₂ ), these raw material powders are blended at a predetermined blending ratio, mixed, and then pressed into a green compact. The green compact is subjected to normal conditions such as 500 to 600 in a vacuum atmosphere. High Al content having a structure in which ZrO ₂ phase is dispersed and distributed on a base material of a Ti-Al-B alloy having a relatively high Al content by sintering at a predetermined temperature within a range of ° C for a predetermined time. Ti-based alloy sintered body and relatively Al content ZrO ₂ phase to form a low Al-containing Ti-based alloy sintered body having a dispersed distribution organization into a green body of a low Ti-Al-B alloys, furthermore, for example, in schematic plan view in FIG. 1 (a), the ( b) an arc ion plating apparatus having a structure shown in a schematic front view, that is, an arc ion plating apparatus having a structure in which a cermet substrate mounting rotary table is provided in the central part of the apparatus, with the rotary table being sandwiched on one side The above-mentioned high Al-containing Ti-based alloy sintered body is disposed opposite to the other side as the cathode electrode (evaporation source) on the other side, and the center of the apparatus on the rotary table is arranged. A plurality of cermet substrates are mounted in a ring shape along the outer periphery of the table at a predetermined distance in the radial direction from the shaft. While rotating, the cermet substrate itself rotates for the purpose of uniforming the thickness of the hard coating layer formed by vapor deposition, and an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode on both sides. Then, when a hard coating layer is formed on the surface of the cermet substrate, the resulting hard coating layer is formed on a substrate made of a composite nitride of Ti, Al, and B [hereinafter referred to as (Ti-Al, B) N]. A hard coating layer of a conventional coated cermet tool having a structure in which the ZrO ₂ phase is dispersed and distributed and formed using the arc ion plating apparatus shown in FIG. 2 (Ti, Al, B) N has a substantially uniform composition throughout the layer thickness, and therefore has a uniform high-temperature strength and a uniform high-temperature hardness and heat resistance, but in the (Ti-Al, B) N substrate, ,rotation When the cermet substrate arranged in a ring shape on the cable is closest to the cathode electrode (evaporation source) of the high Al content Ti-based alloy sintered body having a relatively high Al content on one side, And when the cermet substrate is closest to the cathode electrode of the low Al content Ti-based alloy sintered body having a relatively low Al content on the other side, the Al minimum content is formed in the substrate. Contained points are formed, and by rotating the rotary table, the Al highest content point and the Al lowest content point appear alternately in the layer thickness direction along the layer thickness direction, and from the Al highest content point to the Al It has a component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the lowest content point, the Al lowest content point to the Al highest content point.

(B) In the substrate made of (Ti-Al, B) N having the repeated continuous change component concentration distribution structure of (a) above, the high Al content Ti-based alloy firing which is the cathode electrode (evaporation source) on one side facing each other The Al and B contents in the aggregate correspond to the Al and B contents of the above-described conventional Ti—Al—B alloy for forming (Ti, Al, B) N layers, and the cathode electrode on the other side (evaporation source) The Al content in the low Al content Ti-based alloy sintered body is relatively lower than the Al content of the conventional Ti-Al-B alloy, and a cermet substrate is mounted. Control the rotation speed of the rotary table,
The Al highest content point, composition _{formula: (Ti 1- (M + Z} ) Al M B Z) N ( provided that an atomic ratio, M is 0.40 to 0.60, Z: .01 to 0. 10),
The Al minimum content point is the composition formula: (Ti _{1- (X + Z)} Al _X B _Z ) N (wherein, X is 0.10 to 0.35 in terms of atomic ratio, Z: 0.01 to 0.00). 10),
And the distance in the thickness direction between the adjacent Al highest content point and Al lowest content point adjacent to each other is set to 0.01 to 0.1 μm,
When the ratio of the ZrO ₂ phase dispersed and distributed in the substrate is 0.3 to 15 area% by cross-sectional analysis using an Auger spectroscopic analyzer, the Al highest content point portion in the substrate of the resulting hard coating layer High temperature hardness and heat resistance of conventional (Ti, Al, B) N layer, and high temperature hardness and heat resistance corresponding to high temperature strength, and high temperature strength are shown. Since the Al content is low compared to the part and the Ti content is high, a higher high temperature strength is secured, and the interval between these Al highest content point and Al minimum content point is extremely small. In addition, while maintaining the high temperature hardness and heat resistance of the conventional (Ti, Al, B) N layer as a characteristic of the entire layer, it has a further excellent high temperature strength, Now to hold the excellent surface lubricity by ZrO ₂ phase, therefore, coated cermet tool formed by physical vapor deposition of hard coating layer of such a structure, in particular a very high viscosity, and chips cutting the dispersion distribution When cutting difficult-to-cut materials such as stainless steel and mild steel that are easily welded to the surface at high speed with high heat generation and heavy cutting conditions such as high cutting with high mechanical impact and high feed However, the hard coating layer should have excellent chipping resistance.
The research results shown in (a) and (b) above were obtained.

The present invention has been made based on the above research results. The surface of the cermet substrate is formed on the substrate made of (Ti-Al, B) N, and the ZrO ₂ phase is 0 by cross-sectional analysis by an Auger spectrometer. . Physically vapor-depositing a hard coating layer having a structure dispersed and distributed at a rate of 3 to 15 area% with an average layer thickness of 0.5 to 15 μm,
Further, in the substrate made of (Ti—Al, B) N, the Al highest content point and the Al lowest content point are alternately present at predetermined intervals along the layer thickness direction, and the Al highest content From the point has a component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the Al lowest content point, the Al lowest content point to the Al highest content point,
The Al component maximum content point, composition _{formula: (Ti 1- (M + Z} ) Al M B Z) N ( provided that an atomic ratio, M is 0.40 to 0.60, Z: .01-0 .10),
The Al component minimum content point, composition _{formula: (Ti 1- (X + Z} ) Al X B Z) N ( provided that an atomic ratio, X is 0.10 to 0.35, Z: .01-0 .10),
And the interval between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm.
It is characterized by a coated cermet tool that exhibits excellent chipping resistance with a hard coating layer in high-speed heavy cutting of difficult-to-cut materials.

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 Ti component of the highest Al content point in (Ti-Al, B) N constituting the substrate of the hard coating layer improves the high-temperature strength. The B component has the effect of further improving the high temperature hardness, so that the higher the content ratio of Al and B components, the higher the high temperature hardness and heat resistance. Although it is suitable for high-speed cutting with generation, the M value indicating the Al content ratio exceeds 0.60 in terms of the ratio (atomic ratio) to the total amount of Ti and B, and Z indicating the B content ratio If the value exceeds 0.10, even if there is an adjacent Al minimum content point having high high-temperature strength, a decrease in the high-temperature strength of the layer itself is unavoidable, and as a result, chipping and the like are likely to occur. Even if the M value is less than 0.40, Moreover, even if the Z value is less than 0.01, the desired improvement effect cannot be obtained in the high temperature hardness and heat resistance, so the M value is 0.40 to 0.60, and the Z value is 0.01 to 0.10. Determined.

(B) Composition of Al lowest content point of substrate As mentioned 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 lack of strength, the Ti content is high, while the Al content is low, and the Al minimum content points that have excellent high-temperature strength are alternately interposed in the thickness direction. When the X value indicating the proportion of Ti exceeds 0.35 in terms of the total amount of Ti and B components (atomic ratio), the proportion of Ti is relatively reduced, so the desired excellent high-temperature strength is ensured. On the other hand, if the X value is less than 0.10, the Al minimum content point cannot be provided with a predetermined high-temperature hardness and heat resistance, which causes the progress of wear. At the lowest content point The X value indicating the ratio of Al was determined to be 0.10 to 0.35.
The B component at the lowest Al content point also has the effect of improving the high-temperature hardness by coexistence with the Al component as described above, but the ratio of the Z value indicating the proportion of B to the total amount of Ti and the Al component (atom If the ratio Z is less than 0.01, the desired high-temperature hardness improvement effect cannot be obtained. On the other hand, if the Z value exceeds 0.10, the high-temperature strength having a high Al minimum content point tends to decrease. Since it becomes difficult to ensure excellent chipping resistance, the Z value was determined to be 0.01 to 0.10.

(C) Interval between the highest Al content point and the lowest Al 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 hardness and heat resistance of, and further high temperature strength can not be ensured, and when the interval exceeds 0.1 μm, each point has a defect, that is, if Al is the highest content point, high temperature strength is insufficient, If the Al content is the lowest, the high temperature hardness and insufficient heat resistance will appear locally in the layer, which may cause chipping and promote the progress of wear. .01-0.1 μm.

(D) Proportion of ZrO ₂ phase dispersed and distributed on the substrate The ZrO ₂ phase dispersed and distributed on the substrate of the hard coating layer imparts excellent surface lubricity to the hard coating layer as described above, and is accompanied by particularly high heat generation. Although it has a function to remarkably suppress the welding of chips to the cutting edge even in high-speed heavy cutting of highly viscous difficult-to-cut materials such as stainless steel and mild steel, the ratio of ZrO ₂ phase in the hard coating layer is an Auger spectroscopic analyzer. If the area analysis is less than 0.3 area%, the desired effect cannot be obtained in the above-described action, while if the ratio exceeds 15 area%, the characteristics brought about by the substrate are rapidly deteriorated, causing wear promotion and chipping. Therefore, the ratio of the ZrO ₂ phase in the hard coating layer was determined to be 0.3 to 15 area%.

(E) Average layer thickness of hard coating layer If the layer thickness is less than 0.5 μm, the desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 15 μm, chipping tends to occur. Therefore, the average layer thickness was determined to be 0.5 to 15 μm.

The base of the hard coating layer is repeatedly present at a predetermined interval alternately between the Al minimum content point and the Al maximum content point in the layer thickness direction, and from the Al maximum content point, the Al minimum content point, the Al minimum content A component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the point to the highest Al content point, and further, a hard coating layer having a structure in which the ZrO ₂ phase is dispersed and distributed on the substrate is formed. The coated cermet tool according to the present invention provides a base material for the hard coating layer even when cutting difficult-to-cut materials such as stainless steel and mild steel at high speed with high heat generation and heavy cutting conditions with high mechanical impact. However, it has excellent high-temperature strength, retains high-temperature hardness and heat resistance, and the ZrO ₂ phase significantly reduces the affinity with high-temperature heated chips, which may cause chip welding. Restrained and cutting edge Always maintains excellent surface lubricity, and coupled with the fact that chipping due to chip welding to the cutting edge will not occur on the cutting edge, there is no chipping on the cutting edge and excellent resistance to damage. Demonstrate wearability.

  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, Ti-Al-B alloy powders of various compositions having a relatively high Al content, each having a predetermined average particle diameter in the range of 0.5 to 3 μm, and a relatively Al content Ti-Al-B alloy powders of various low composition and further ZrO ₂ powder, these raw material powders are blended into a predetermined blending composition, wet-mixed for 72 hours with a ball mill, dried, and then compacted at a pressure of 100 MPa The compact is pressed into a body and sintered in a vacuum of 6 Pa at a predetermined temperature within a range of 500 to 600 ° C. for 1 hour under conditions of a relatively high Al content. A high Al content Ti-based alloy sintered body having a structure in which a ZrO ₂ phase is dispersed and contained at a predetermined ratio in a base material of a Ti—Al—B alloy, and Ti—Al— having various compositions having a relatively low Al content. into a green body of B alloy ZrO ₂ phase is in a predetermined Sintered Ti-Al-B alloy powders of various compositions with relatively high Al content and low Al content Ti-based alloy sintered bodies (for forming the hard coating layer of the present invention) having a dispersed and mixed structure A body (for forming a conventional hard coating layer) was formed.

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. Mounted along the outer periphery of the table at a predetermined distance in the radial direction from the central axis on the rotary table, and used as the cathode electrode (evaporation source) on one side for forming the highest Al content point with various component compositions An Al-containing Ti-based alloy sintered body, and a low Al-containing Ti-based alloy sintered body for forming the lowest Al content point as a cathode electrode (evaporation source) on the other side are arranged opposite to each other with the rotary table interposed therebetween, and a bombard cleaning metal Ti is also attached. First, the inside of the apparatus is evacuated and kept at a vacuum of 0.5 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the thermometer that rotates while rotating on the rotary table. A DC bias voltage of −1000 V is applied to the substrate, 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 bombarding, and then the apparatus A nitrogen gas is introduced as a reaction gas into the reaction atmosphere of 2 Pa, a DC bias voltage of −100 V is applied to the cermet substrate rotating while rotating on the rotary table, and each cathode electrode (the Al A high Al-containing Ti-based alloy sintered body for forming the highest content point and a low Al-containing Ti-based alloy sintered body for forming the lowest Al content point) and an anode electrode to generate an arc discharge, Therefore, on the surface of the cermet substrate, the highest Al content point and the lowest Al content point of the target composition shown in Tables 3 and 4 along the layer thickness direction. Are alternately present at the target intervals shown in Tables 3 and 4, and the Al and Ti content ratios from the highest Al content point to the lowest Al content point and from the lowest Al content point to the highest Al content point Has a structure in which the ZrO ₂ phase is dispersed and contained at the target ratios shown in Tables 3 and 4 on the substrate having the component concentration distribution structure in which the material continuously changes, and the target layer thickness shown in Tables 3 and 4 By depositing the hard coating layer, the surface-coated cermet throwaway tips (hereinafter referred to as the present invention-coated chips) 1 to 16 as the present invention-coated 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. Inserted into the plating device, each one of Ti-Al-B alloys with various composition as cathode electrode (evaporation source) was mounted, and also bombard cleaning metal Ti was mounted. The inside of the apparatus was heated to 500 ° C. with a heater while maintaining a vacuum of 0.5 Pa or less, and then a −1000 V DC bias voltage was applied to the cermet substrate, and the metal Ti and anode of the cathode electrode were applied. An electric current of 100 A is passed between the electrodes to generate an arc discharge, thereby cleaning the surface of the cermet substrate with Ti bombardment, and then introducing nitrogen gas as a reaction gas into the apparatus. And a bias voltage applied to the cermet substrate is lowered to -100 V to generate an arc discharge between the cathode electrode and the anode electrode, thereby the cermet substrates A-1 to A- 10 and B-1 to B-6 have the target composition and target layer thickness shown in Table 5 and substantially no composition change along the layer thickness direction (Ti, Al, B). ) By depositing a hard coating layer composed of an N layer, conventional surface-coated cermet throwaway tips (hereinafter referred to as conventional coated chips) 1 to 16 as conventional coated cermet tools were produced, respectively.

Next, in the state where each of the present invention coated chips 1-16 and the conventional coated chips 1-16 are screwed to the tip of the tool steel tool with a fixing jig,
Work material: JIS / S10C round bar,
Cutting speed: 400 m / min. ,
Cutting depth: 2mm,
Feed: 0.6 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed high-feed cutting test of mild steel under the following conditions (cutting conditions A) (normal cutting speed and feed are 250 m / min. And 0.4 mm / rev.),
Work material: JIS / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 140 m / min. ,
Cutting depth: 3.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 3 minutes
(Continuous cutting speed and cutting are 80 m / min. And 2 mm), and further,
Work material: JIS / SUS304 round bar,
Cutting speed: 240 m / min. ,
Incision: 3mm,
Feed: 0.2 mm / rev. ,
Cutting time: 8 minutes
(Continuous cutting speed and depth of cut is 170 m / min. And 1.5 mm) for all stainless steels under the above conditions (cutting condition C). The flank wear width of the blade 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 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 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 base (end mill) C- having a four-blade square shape with a diameter x length of the cutting edge portion of 6 mm x 13 mm, 10 mm x 22 mm, and 20 mm x 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. 1, the highest Al content point and the lowest Al 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 alternately, and the Al The substrate having a component concentration distribution structure in which the content ratios of Al and Ti continuously change from the highest content point to the Al lowest content point and from the Al lowest content point to the Al highest content point are also shown in Table 8 have a tissue that ZrO ₂ phase containing dispersed at a ratio, and also by depositing a hard coating layer of the target layer thicknesses shown in Table 8, the present invention a surface coating of the present invention coated cermet tool cermet Ltd. 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 / SUS304 plate,
Cutting speed: 80 m / min. ,
Groove depth (cut): 1.5 mm,
Table feed: 350 mm / min,
Stainless steel dry high-speed high-feed groove cutting test under normal conditions (normal cutting speed and table feed are 30 m / min. And 130 mm / min), the present invention coated end mills 4 to 6 and the conventional coated end mills 4 to 6 Is
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S10C plate,
Cutting speed: 200 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 900 mm / min,
With regard to the dry high-speed high-feed groove cutting test of mild steel under the following conditions (normal cutting speed and table feed are 120 m / min. And 470 mm / min), the coated end mills 7 and 8 of the present invention and the conventional coated end mills 7 and 8 ,
Work material: Plane size: 100 mm × 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 75 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 120 mm / min,
Stainless steel dry-type high-speed and high-grooving groove cutting test (normal cutting speed and groove depth (cutting) are 30 m / min. And 3 mm), respectively. The cutting groove length was measured until the flank wear width of the outer peripheral 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 substrates D-4 to D-6), and 16 mm × 45 mm (cermet substrates D-7 and D-8), and the twist angle is 30 degrees. Cermet substrates (drills) D-1 to D-8 having a two-blade shape were produced, respectively.

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 lowest Al 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 that repeatedly exists and the content ratio of Al and Ti continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, by also to have a tissue of ZrO ₂ phase containing dispersed at the target the proportions shown in Table 10, and is also deposited hard layer of the target layer thicknesses shown in Table 10, the present invention coated cermet tool The present invention surface coating cermet drill Te (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 / SUS304 plate,
Cutting speed: 80 m / min. ,
Feed: 0.16mm / rev,
Hole depth: 6mm,
Wet high-speed high-feed drilling test of stainless steel under the following conditions (normal cutting speed and feed are 35 m / min. And 0.08 mm / rev.), The present invention coated drills 4 to 6 and the conventional coated drill 4 to For 6,
Work material: Plane size: 100 mm × 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 70 m / min. ,
Feed: 0.24mm / rev,
Hole depth: 16mm
Wet high-speed high-feed drilling test of stainless steel under the following conditions (normal cutting speed and feed are 35 m / min. And 0.16 mm / rev.), The present invention coated drills 7 and 8 and the conventional coated drill 7, For 8,
Work material: Plane dimension: 100 mm × 250 mm, thickness: 50 mm JIS / S10C plate,
Cutting speed: 150 m / min. ,
Feed: 0.35mm / rev,
Hole depth: 32mm
Wet high-speed high-feed drilling test (normal cutting speed and feed are 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 1-16, conventional coated end mills 1-8, and conventional coated drills 1-8, the contents of Ti, Al, B, and Zr along the thickness direction are Auger spectroscopic analyzers In the hard coating layer of the coated cermet tool of the present invention, the composition and spacing of the Al highest content point and the Al lowest content point are substantially the same as the target values, respectively, along the layer thickness direction in the substrate. In addition, Al and Ti are contained from the highest Al content point to the lowest Al content point and from the lowest Al content point to the highest Al content point. Ratio has a continuously changing component concentration distribution structure, it was confirmed that further ZrO ₂ phase is dispersed therein to a target value substantially the base material at the same rate, and also the average layer thickness of the hard layer goals The value was substantially the same as the 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, along the layer thickness direction, Al minimum content points having excellent high temperature strength and Al maximum content points having high temperature hardness and heat resistance are alternately present at predetermined intervals. And a substrate having a component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the Al highest content point to the Al lowest content point, and from the Al lowest content point to the Al highest content point, ZrO ₂ The coated cermet tool of the present invention formed by physically vapor-depositing a hard coating layer having a structure in which phases are distributed and distributed is a high-speed condition that involves high-temperature generation and high mechanical impact. Even when performed under heavy cutting conditions such as high cutting and high feed, the hard coating layer exhibits excellent wear resistance without occurrence of chipping, whereas the hard coating layer follows the thickness direction. In a conventional coated cermet tool composed of a (Ti, Al, B) N layer that has no qualitative compositional change, due to the lack of high-temperature strength of the hard coating layer, it is coupled with high weldability to difficult-to-cut materials. It is clear that chipping occurs and the service life is reached in a relatively short time due to this.
As described above, the coated cermet tool of the present invention is capable of cutting not only normal conditions but also difficult-to-cut materials such as stainless steel and mild steel, with high heat generation and high mechanical impact. Even under heavy cutting conditions, chipping does not occur and excellent wear resistance is demonstrated over a long period of time, so it is fully satisfactory for cutting labor and energy savings and cost reduction. It can be done.

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)

The surface of a cermet substrate composed of tungsten carbide-based cermet or titanium carbonitride-based cermet is formed on a substrate made of a composite nitride of Ti, Al, and B (boron), and a zirconium oxide phase is obtained by surface analysis using an Auger spectrometer. A hard coating layer having a structure dispersed and distributed at a rate of 0.3 to 15 area% is physically vapor-deposited with an average layer thickness of 0.5 to 15 μm;
Further, the base composed of the composite nitride of Ti, Al, and B, the Al highest content point and the Al lowest content point are alternately present at predetermined intervals along the layer thickness direction, and the Al highest content From the point has a component concentration distribution structure in which the content ratio of Al and Ti continuously changes from the Al lowest content point, the Al lowest content point to the Al highest content point,
The Al highest content point, composition _{formula: (Ti 1- (M + Z} ) Al M B Z) N ( provided that an atomic ratio, M is 0.40 to 0.60, Z: .01 to 0. 10),
The Al minimum content point is the composition formula: (Ti _{1- (X + Z)} Al _X B _Z ) N (wherein, X is 0.10 to 0.35 in terms of atomic ratio, Z: 0.01 to 0.00). 10),
And the interval between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
A surface-coated cermet cutting tool that exhibits excellent chipping resistance in high-speed heavy cutting of difficult-to-cut materials characterized by

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