JP2007260787A - Surface coated cermet-made cutting throw-away tip having hard coating layer exhibiting excellent abrasion resistance in high-speed cutting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated cutting tip having a hard coating layer exhibiting excellent abrasion resistance in high-speed cutting. <P>SOLUTION: One layer of the hard coating layers is structured of a modified α type Al<SB>2</SB>O<SB>3</SB>layer showing an inclination frequency distribution graph, in which the peak exists in an inclination section within a range of 83-90 degree and the sum of frequency existing within the range of 83-90 degree occupies 45% or more of the whole of the frequency in the inclination frequency distribution graph, in regard to an inclination frequency distribution graph formed by irradiating each of crystal particles having hexagonal crystal lattice existing within a measurement range of a surface polishing surface with the electronic beam by using a field emission type scanning microscope, measuring inclination formed by a normal of a surface 0001 as a crystal surface of the crystal particle against a normal of the surface polishing surface, and forming the distribution graph based on a result of the measurement. The surface is polished to have surface roughness Ra of 0.2 μm or less, and the polished surface is formed with a hard coating layer residual stress reducing pattern. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

In the present invention, no chipping (small chipping) is generated in the hard coating layer, and an aluminum oxide layer (hereinafter referred to as an Al ₂ O ₃ layer) constituting the upper layer is formed by cutting various steels and cast irons. The present invention relates to a surface-coated cermet cutting throwaway tip (hereinafter referred to as a coated cutting tip) that exhibits excellent wear resistance even when processing is performed at high speed.

Conventionally, generally, for example, as illustrated in a schematic perspective view in FIG. 13, a tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet is used, and the center portion. A cermet base (hereinafter referred to collectively as a chip base) having a tool mounting bolt through hole (in the case where the mounting is performed by clamping with a clamp piece, the bolt through hole does not exist). ) On the entire rake face and flank face including the cutting edge ridge
(1) Ti carbide (hereinafter referred to as TiC) layer, nitride (hereinafter also referred to as TiN) layer, carbonitride (hereinafter referred to as TiCN) layer, all of which are formed by chemical vapor deposition of the lower layer. A Ti compound comprising one or more of a carbon oxide (hereinafter referred to as TiCO) layer and a carbonitride oxide (hereinafter referred to as TiCNO) layer and having an overall average layer thickness of 3 to 20 μm layer,
(2) Al ₂ O ₃ layer (hereinafter referred to as conventional Al ₂ O ₃ layer) having an α-type crystal structure when the upper layer has an average layer thickness of 1 to 15 μm and is chemically vapor-deposited.
A coated cutting tip formed by vapor-depositing the hard coating layer constituted by the above (1) and (2) is known, and this coated cutting tip is used for continuous cutting and intermittent cutting of various steels and cast irons, for example. It is well known to be used.

In general, the Ti compound layer that constitutes the hard coating layer of the above-mentioned coated cutting tip and the conventional Al ₂ O ₃ layer have a granular crystal structure, and further, the TiCN layer that constitutes the Ti compound layer is formed of the layer itself. For the purpose of improving the strength, a vertically grown crystal structure formed by chemical vapor deposition at a medium temperature range of 700 to 950 ° C. using a mixed gas containing an organic carbonitride as a reaction gas in a normal chemical vapor deposition apparatus. It is also known to have
Japanese Unexamined Patent Publication No. 6-31503 Japanese Patent Laid-Open No. 6-8010

In recent years, the performance of cutting machines has been remarkable. On the other hand, there is a strong demand for labor saving and energy saving and further cost reduction for cutting work, and along with this, cutting work tends to be further accelerated. For coated cutting tips, there is no problem when used for continuous cutting and interrupted cutting under normal conditions such as steel and cast iron, but especially when this is used under high-speed cutting conditions. Since the wear resistance of the conventional Al ₂ O ₃ layer constituting the layer is insufficient, the wear progresses rapidly and the service life is reached in a relatively short time.

The present inventors have, from the viewpoint as described above, focuses on coated cutting tip prior the Al ₂ O ₃ layer described above constituting the upper layer of the hard coating layer, particularly the conventional the Al ₂ O ₃ layer resistant As a result of research to improve wearability,
(A-1) The conventional Al ₂ O ₃ layer as the upper layer of the hard coating layer of the above-mentioned conventional coated cutting tip is generally a normal chemical vapor deposition apparatus,
Reaction gas composition: by _{volume%, AlCl 3: 1~5%,} CO 2: 3~7%, HCl: 0.3~3%, H 2 S: 0.02~0.4%, H 2: remainder ,
Reaction atmosphere temperature: 950-1100 ° C.
Reaction atmosphere pressure: 6-13 kPa,
The conventional Al ₂ O ₃ layer formed under the normal conditions is schematically illustrated in FIGS. 1A and 1B using a field emission scanning electron microscope. As shown by the above, the crystal grains having the hexagonal crystal lattice existing within the measurement range of the surface polished surface are irradiated with an electron beam, and the crystal plane of the crystal grains is relative to the normal line of the polished surface. The inclination angle formed by the normal of the (0001) plane is measured, and among the measurement inclination angles, the measurement inclination angles within the range of 45 to 90 degrees are divided for each pitch of 0.25 degrees, and within each division When the inclination angle number distribution graph formed by counting the frequencies existing in the graph is created, as shown in FIG. 3, the distribution of the measured inclination angles on the (0001) plane is in the range of 45 to 90 degrees, and the inclination angle is unbiased. Show the number distribution graph.

(A-2) On the other hand, using a normal chemical vapor deposition apparatus,
Reaction gas composition: by _{volume%, AlCl 3: 1~5%,} CO 2: 3~7%, HCl: 0.3~3%, SF 6: 0.1~1%, H 2: remainder,
Reaction atmosphere temperature: 750 to 900 ° C.
Reaction atmosphere pressure: 55-80 kPa,
Conditions, i.e. in comparison with the conventional the Al ₂ O ₃ layer formed above conditions, at a relatively low temperature and high pressure conditions, and as a reaction gas, Al in conditions using SF ₆ in place of H ₂ S ₂ O ₃ When the layer is formed, the resulting Al ₂ O ₃ layer also has an α-type crystal structure, which is also shown in FIGS. 1A and 1B using a field emission scanning electron microscope. As shown, each crystal grain having a hexagonal crystal lattice, which is also present in the measurement range of the surface polished surface, is irradiated with an electron beam, and is a crystal plane of the crystal grain with respect to the normal line of the polished surface. The inclination angle formed by the normal of the (0001) plane is measured, and among the measurement inclination angles, the measurement inclination angles within the range of 45 to 90 degrees are divided for each pitch of 0.25 degrees, and within each division Fig. 2 shows an example of an inclination angle distribution graph obtained by aggregating the frequencies existing in As shown in the graph, a sharp maximum peak appears at a specific position in the tilt angle section. According to the test results, when the reaction atmosphere pressure in the chemical vapor deposition apparatus is changed within the range of 55 to 80 kPa as described above, the sharp maximum peak is obtained. The position where the peak appears changes within the range of 83 to 90 degrees of the inclination angle section, and the total of the frequencies existing in the range of 83 to 90 degrees is 45% or more of the entire degrees in the inclination angle frequency distribution graph. The α-type Al ₂ O ₃ layer (hereinafter referred to as a modified Al ₂ O ₃ layer) in which the highest peak of the tilt angle section appears in the range of 83 to 90 degrees in the resulting tilt angle number distribution graph. ) Must exhibit much higher wear resistance than the conventional Al ₂ O ₃ layer formed under the normal conditions.

(B-1) On the other hand, as illustrated in the schematic perspective view of FIG. 11, on the entire rake face and flank face including the cutting edge ridge line portion of the modified Al ₂ O ₃ layer constituting the upper layer of the hard coating layer ,
(B-1-1) First, as a lower layer, the reaction gas composition is in volume%,
TiCl ₄ : 0.2 to 10%,
CO ₂ : 0.1 to 10%,
Ar: 5 to 60%,
H ₂ : Remaining
And
Reaction atmosphere temperature: 800-1100 ° C.
Reaction atmosphere pressure: 4 to 70 kPa (30 to 525 torr),
And having an average layer thickness of 0.1 to 3 μm and a ratio of oxygen to Ti of 1.25 to 1.90 as measured by an Auger spectrometer,
Composition formula: TiO _W ,
In the case of
W: 1.25 to 1.90 in atomic ratio,
Forming a titanium oxide layer that satisfies
(B-1-2) Next, on the titanium oxide layer (lower layer), as an upper layer, normal conditions, that is, the reaction gas composition, in volume%,
TiCl ₄ : 0.2 to 10%,
N ₂ : 4-60%,
H ₂ : Remaining
And
Reaction atmosphere temperature: 800-1100 ° C.
Reaction atmosphere pressure: 4 to 90 kPa (30 to 675 torr),
When a TiN layer having an average layer thickness of 0.05 to 2 μm is formed under the conditions described above,
(B-1-3) At the time of forming the TiN layer (upper layer), oxygen in the titanium oxide layer constituting the lower layer diffuses and the upper layer (TiN layer) is constituted by a titanium oxynitride layer. However, in this case, the titanium oxide layer, which is the lower layer after the formation of the upper layer (the titanium oxynitride layer), has a ratio of oxygen measured by an Auger spectrometer at the center in the thickness direction. 1.2 to 1.7 atomic ratio to Ti,
Composition formula: TiO _x ,
In the case of
X: 1.2 to 1.7 in atomic ratio,
Titanium oxide layer that satisfies
(B-1-4) Further, the upper layer composed of the titanium oxynitride layer is also measured at the center in the thickness direction with an Auger spectroscopic analyzer, and the proportion of diffused oxygen is the atomic ratio with respect to nitrogen (N). 0.01-0.4, i.e.
Composition formula: TiN _1-Y (O) _Y ,
(Where (O) represents diffused oxygen from the lower abrasive layer),
Y: 0.01 to 0.4 in atomic ratio
Titanium nitride oxide layer that satisfies

(B-2) With the titanium nitride oxide layer (upper layer) and the titanium oxide layer (lower layer) deposited and formed,
On the vapor deposition surface at wet blast, as the injection abrasive, aluminum oxide fine 15-60 wt% as a percentage of the total amount of water (hereinafter, indicated by Al ₂ O ₃ fine) polishing liquid formulated with the When sprayed, the titanium oxynitride layer and the titanium oxide layer are pulverized and pulverized by the Al ₂ O ₃ fine particles, and become titanium oxynitride fine particles and titanium oxide fine particles and act as an abrasive in the presence of the Al ₂ O ₃ fine particles. Then, as illustrated in a schematic perspective view in FIG. 12, the surface of the modified Al ₂ O ₃ layer constituting the upper layer of the hard coating layer is polished. As a result, the modified Al ₂ O after polishing is polished. The surface of each of the _three layers is a measurement based on the compliant standard JIS B0601-1994 (the following surface roughness indicates all measured values based on the compliant standard), and Ra: a surface roughness of 0.2 μm or less. Smoothed to Uninari, the surface of the reforming the Al ₂ O ₃ layer is Ra: When 0.2μm smoothed below the surface roughness, significant improvement effect appears so made that the chipping resistance of the hard coating layer.

(C-1) On the other hand, the hard coating layer is formed by being deposited on the surface of the chip substrate at a reaction temperature of about 1000 ° C. and cooled to room temperature by a chemical vapor deposition apparatus. In the process, since the thermal expansion coefficient of the hard coating layer is relatively larger than the thermal expansion coefficient of the chip substrate, tensile stress remains in the hard coating layer. Residual tensile stress in the layer acts to promote chipping in high-speed cutting.

(C-2) On the other hand, a single basic shape mark, for example, a single basic shape mark such as a circle, a triangle and a quadrangle, or a similar shape thereof, is used for either the rake face or the flank face of the coated cutting tip. As shown in a schematic perspective view of an embodiment in which the single basic shape mark is circular, for example, in FIGS. 4 to 10 using a laser beam over the entire surface of both surfaces, the single basic Either or both of the shape mark and the collective mark of the single basic shape mark are distributed (in this case, the examples shown in FIGS. 4 to 6 have a relatively thin hard coating layer, 8 and FIGS. 9 and 10 show the distribution mode when the layer thickness increases, and the single basic shape mark is exposed to any one of the constituent layers of the hard coating layer. Digging surface (In this case, the depth of the exposed surface of the single basic shape mark is individually adjusted in accordance with the layer thickness of the hard coating layer. When a laser beam irradiation pattern is formed at a depth corresponding to 5 to 20%), the residual stress of the hard coating layer is remarkably reduced. By the formation of the hard coating layer residual stress reduction pattern, In particular, the occurrence of chipping of the hard coating layer during high-speed cutting is significantly suppressed.

(D) Therefore, when the upper layer of the hard coating layer is measured on the surface polished surface, the distribution of the measured inclination angle of the (0001) plane has the highest peak in the inclination angle section within the range of 83 to 90 degrees, The modified Al ₂ O ₃ layer showing an inclination angle distribution graph in which the total of the frequencies existing in the range of 83 to 90 degrees occupies a ratio of 45% or more of the entire frequencies in the inclination angle distribution graph. Wear resistance is further improved, and the surface of the modified Al ₂ O ₃ layer is smoothed to a surface roughness of Ra: 0.2 μm or less, and a hard coating layer is formed by forming a residual stress reduction pattern. Since the chipping resistance of the layer is also improved, the coated cutting tip formed by vapor-depositing the hard coating layer having such a configuration is the same as the upper layer of the hard coating layer even if the cutting process is performed at high speed. (0001) plane In comparison with the conventional coated cutting chip formed by the conventional distribution of measured tilt angle indicates an unbiased inclination angle frequency distribution graph in the range of 45 to 90 degrees the Al ₂ O ₃ layer, the chipping hard layer It has no wear, exhibits excellent wear resistance, and exhibits excellent cutting performance over a long period of time.
The research results shown in (a) to (d) above were obtained.

The present invention has been made based on the above research results, and is provided on the entire surface of the rake face and the flank face including the cutting edge ridge line portion of the chip base,
(1) The lower layer consists of one or more of TiC layer, TiN layer, TiCN layer, TiCO layer, and TiCNO layer, all formed by chemical vapor deposition, and an overall average layer of 3 to 20 μm A Ti compound layer having a thickness;
(2) a conventional Al ₂ O ₃ layer in which the upper layer has an average layer thickness of 1 to 15 μm;
In the coated cutting tip formed by vapor-depositing the hard coating layer composed of (1) and (2) above,
(A) Using the field emission scanning electron microscope, the conventional Al ₂ O ₃ layer is irradiated with an electron beam on each crystal grain having a hexagonal crystal lattice existing within the measurement range of the surface polishing surface, and the polishing is performed. The inclination angle formed by the normal line of the (0001) plane that is the crystal plane of the crystal grain is measured with respect to the normal line of the plane, and the measurement inclination angle within the range of 45 to 90 degrees among the measurement inclination angles Is divided for each pitch of 0.25 degrees, and when the slope angle distribution graph is formed by summing up the frequencies existing in each section, the highest peak appears in the slope angle section within the range of 83 to 90 degrees. A modified Al ₂ O ₃ layer showing an inclination angle distribution graph that is present and the total of the frequencies within the range of 83 to 90 degrees occupies 45% or more of the entire frequency in the inclination angle distribution graph ,
Consisting of
(B) On the entire surface of the modified Al ₂ O ₃ layer, which is the upper layer of the hard coating layer,
(B-1) The lower layer has an average layer thickness of 0.1 to 3 μm, and
Composition formula: TiO _x ,
, Measure the central part in the thickness direction with an Auger spectrometer,
X: 1.2 to 1.7 in atomic ratio,
Satisfying titanium oxide layer,
(B-2) The upper layer has an average layer thickness of 0.05 to 2 μm, and
Composition formula: TiN _1-Y (O) _Y ,
(However, (O) indicates the diffused oxygen from the Ti oxide layer), the central portion in the thickness direction is also measured with an Auger spectrometer,
Y: 0.01 to 0.4 in atomic ratio
Satisfying titanium oxynitride layer,
In a state where the abrasive layer constituted by (b-1) and (b-2) is formed by vapor deposition,
(B-3) In wet blasting, a polishing liquid containing 15 to 60% by mass of Al ₂ O ₃ fine particles as a spraying abrasive in a proportion of the total amount with water is sprayed.
Modification that constitutes the upper layer of the hard coating layer in the presence of the ground titanium oxide particles in the lower layer, the ground titanium nitride oxide particles in the upper layer, and the Al ₂ O ₃ particles as the spray abrasive. Grind the rake face portion and the flank face portion including at least the cutting edge ridge line portion of the Al ₂ O ₃ layer, and set the surface roughness of these polished surfaces to Ra: 0.2 μm or less,
(C) Furthermore, either one or both of the rake face and the flank face of the polished surface, or the single basic shape mark and the collective mark of the single basic shape mark are distributed over the entire surface of both surfaces. A hard coating layer residual stress reduction pattern is formed by irradiating a laser beam with the single basic shape mark as a dug surface where any one of the constituent layers of the hard coating layer is exposed. ,
The hard coating layer is characterized by a coated cutting tip that exhibits excellent wear resistance in high-speed cutting.

The reason why the numerical values are limited as described above will be described below with respect to the constituent layers of the hard coating layer of the coated cutting tip of the present invention.
(A) Hard coating layer (a-1) Ti compound layer (lower layer)
The Ti compound layer basically exists as a lower layer of the modified Al ₂ O ₃ layer, and the hard coating layer has high temperature strength due to its excellent high temperature strength, and is modified from the chip substrate. It adheres firmly to any of the Al ₂ O ₃ layers, and thus has the effect of contributing to improving the adhesion of the hard coating layer to the chip substrate. However, when the average layer thickness is less than 3 μm, the above effect is sufficiently exerted. On the other hand, if the average layer thickness exceeds 20 μm, it becomes easy to cause thermoplastic deformation particularly in high-speed cutting accompanied by high heat generation, which causes uneven wear. It was defined as ˜20 μm.

(A-2) Modified Al ₂ O ₃ layer (upper layer)
As described above, the highest peak position of the measured inclination angle in the inclination angle number distribution graph of the modified Al ₂ O ₃ layer is changed by changing the reaction atmosphere pressure in the chemical vapor deposition apparatus. When the reaction atmosphere pressure is 55 to 80 kpa, the highest peak appears in the inclination angle section within the range of 83 to 90 degrees, and the total of the frequencies existing in the range of 83 to 90 degrees is the inclination angle number distribution. An inclination angle frequency distribution graph occupying a ratio of 45% or more of the entire frequency in the graph is shown. Therefore, even if the reaction atmosphere pressure is out of the range, it is out of the range. The maximum peak position of the measured inclination angle is out of the range of 83 to 90 degrees, and in this case, the desired excellent wear resistance cannot be ensured.
Further, if the average layer thickness of the entire modified Al ₂ O ₃ layer is less than 1 μm, the excellent characteristics of this cannot be fully exhibited, while if the average layer thickness exceeds 15 μm, Since chipping (slight chipping) is likely to occur at the cutting edge, the overall average layer thickness is determined to be 1 to 15 μm.

(B) Abrasive material layer As described above, the titanium oxynitride layer constituting the upper layer first forms a titanium oxide layer in which the oxygen ratio is 1.25 to 1.90 (W value) in terms of atomic ratio to Ti. Then, it is formed by depositing a TiN layer on the titanium oxide layer under normal conditions. Therefore, diffusion of oxygen from the titanium oxide layer during the formation of the TiN layer is indispensable. When the W value of the titanium oxide layer is less than 1.25, the diffusion reaction of oxygen into the TiN layer is drastically reduced, and the ratio of diffused oxygen (Y value) in the upper layer is 0.01 by atomic ratio. While the same W value is 1. If the composite oxide layer 90 is exceeded, the proportion of diffused oxygen (Y value) in the upper layer will increase beyond 0.40 in atomic ratio, so the W value is determined to be 1.25 to 1.90. In this case, the oxygen ratio (X value) in the lower layer (titanium oxide layer) after the upper layer formation takes an atomic ratio in the range of 1.2 to 1.7. In other words, when the X value of the lower layer after forming the upper layer satisfies 1.2 to 1.7, the Y value of the upper layer satisfies 0.01 to 0.40.
In this case, the X value of the lower layer and the Y value of the upper layer are set to 1.2 to 1.7 and 0.01 to 0.40, respectively. It is obtained from many test results that these abrasive layers are pulverized and atomized in a suitable state at the time of wet blasting, and exhibit an excellent polishing function sufficiently. Based on this. Therefore, if the X value and Y value are out of the range of 1.2 to 1.7 and 0.01 to 0.40, respectively, the pulverization and atomization at the time of wet blasting of the abrasive layer is not satisfactorily performed, which is excellent. The polishing function cannot be expected.
Further, the average layer thicknesses of the upper layer and the lower layer were set to 0.05 to 2 μm and 0.1 to 3 μm, respectively, when the average layer thickness was less than 0.05 μm and less than 0.1 μm. The ratio of the pulverized titanium oxide fine particles in the lower layer and the fine pulverized titanium oxynitride fine particles in the upper layer is too small to perform the polishing function sufficiently, while the average layer thickness is 2 μm and 3 μm, respectively. Even if it exceeds the range, the polishing function will rapidly decrease, and in any case, the surface of the composite oxide layer cannot be polished to a surface roughness of Ra: 0.2 μm or less. is there.

(C) The Al ₂ O ₃ fine of Al ₂ O ₃ fine fraction polishing liquid of the polishing liquid, pulverization oxynitride of pulverized titanium oxide fine and the upper layer of the lower layer of the abrasive layer during wet blasting Although it acts to polish the surface of the modified composite oxide layer in the state of coexisting with the titanium fine particles, even if the ratio is less than 15% by mass or more than 60% by mass in the total amount with water Since the polishing function is abruptly lowered, the ratio was determined to be 15 to 60% by mass.

In the coated cutting tip of the present invention, the upper layer of the hard coating layer has the highest peak in the inclination angle section within the range of the measured inclination angle of the (0001) plane within the range of 83 to 90 degrees as measured by the polished surface. In addition, an inclination angle number distribution graph in which the total of the frequencies existing in the range of 83 to 90 degrees occupies a ratio of 45% or more of the entire degrees in the inclination angle number distribution graph is shown, and as a result, the wear resistance is further improved. consists of modifying the Al ₂ O ₃ layer as the those improvements, further rake face portion and flank portions including at least the cutting edge line portion of the reforming the Al ₂ O ₃ layer is, Ra: 0.2 [mu] m below the surface The hard coating layer is resistant to the hard coating layer by reducing the residual stress of the hard coating layer formed by laser beam irradiation over one of the rake face and flank surface of the polished surface, or the entire surface of both surfaces. Chi As a result, the cutting performance of various steels and cast irons can be improved at a high speed without causing chipping, and the service life is further extended. It is possible.

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

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, and Co powder all having an average particle diameter of 0.5 to 3 μm are prepared as raw material powders. These raw material powders are blended in the blending composition shown in Table 1, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then pressed into a green compact of a predetermined shape at a pressure of 98 MPa. The green compact was sintered in a vacuum of 5 Pa at a predetermined temperature within a range of 1370 to 1470 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.05 mm. The chip bases A to F made of a WC-based cemented carbide having a throwaway tip shape specified in ISO · CNMG120408 were produced.

Further, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC, all having an average particle diameter of 0.5 to 2 μm. Prepare powder, Co powder, and Ni powder, blend these raw material powders into the composition shown in Table 2, wet mix with a ball mill for 24 hours, dry, and press-mold into a green compact at 98 MPa pressure The green compact is sintered in a nitrogen atmosphere of 1.3 kPa at a temperature of 1540 ° C. for 1 hour, and after sintering, the cutting edge portion is subjected to a honing process of R: 0.07 mm. Tool bases a to f made of TiCN base cermet having a chip shape of ISO standard / CNMG120408 were formed.

Then, each of these tool bases A to F and tool bases a to f is charged into a normal chemical vapor deposition apparatus,
(A) First, Table 3 (l-TiCN in Table 3 indicates the conditions for forming a TiCN layer having a vertically elongated crystal structure described in JP-A-6-8010, and the other conditions are ordinary granularity. Under the conditions shown in Table 6), the Ti compound layer having the combination shown in Table 6 and the target layer thickness is deposited as a lower layer of the hard coating layer,
Next, under the low temperature and high pressure conditions shown in Table 3, the modified Al ₂ O ₃ layer as the upper layer was formed by vapor deposition with the combinations and target layer thicknesses also shown in Table 6.
(B) Next, a titanium oxide layer [TiO _W (1) to (6) for forming the lower layer of the abrasive layer is formed on the entire surface of the modified Al ₂ O ₃ layer constituting the upper layer of the hard coating layer. After forming under the conditions shown in Table 4, the titanium nitride layer for forming the upper layer (TiN layer) is vapor-deposited with the target layer thickness shown in Table 7 under the conditions shown in Table 4 as well. The composition shown in Table 7, that is, the central portion in the thickness direction is measured with an Auger spectroscopic analyzer to form an abrasive layer composed of a lower layer and an upper layer of the X value and Y value shown in Table 7, respectively ( FIG. 11),
(C) Subsequently, the coated cutting tip for forming the abrasive layer composed of the lower layer and the upper layer is subjected to wet blasting under the blasting conditions shown in Table 5 and in the combinations shown in Table 7, The rake face portion and the flank face portion including the cutting edge ridge line portion of the modified Al ₂ O ₃ layer are polished to the surface roughness shown in Table 7 in the state where the abrasive layer is present around the mounting hole. (See FIG. 12),
(D) Furthermore, using a laser beam irradiation device, the hard coating layer for surface polishing,
Laser beam output: 10W
The shape of a single basic shape mark: a circle with a diameter of 0.5 mm,
Hard coating layer residual stress reduction pattern: any one of the implementation patterns shown in FIGS. 4 to 10 is applied in the combination shown in Table 7.
Depth of digging on the exposed surface of a single basic shape mark: the depth shown in Table 7 as a percentage of the total target layer thickness of the hard coating layer,
The coated cutting chips 1 to 13 of the present invention were manufactured by forming a hard coating layer residual stress reduction pattern under the conditions described above.

For the purpose of comparison, the lower layer of the hard coating layer is formed by vapor deposition under the same conditions as those of the present invention coated cutting chips 1 to 13, and the upper layer is formed under the normal conditions shown in Table 3 as Table 8. Conventionally coated cutting chips 1 to 13 were manufactured without forming the above-described wet blasting and hard coating layer residual stress reduction pattern by depositing and forming a conventional Al ₂ O ₃ layer with the combination and target layer thickness shown in FIG. .

Next, field emission scanning is performed on the modified Al ₂ O ₃ layer and the conventional Al ₂ O ₃ layer constituting the upper layer of the hard coating layer of the present invention coated cutting chips 1 to 13 and the conventional coated cutting chips 1 to 13. An inclination angle number distribution graph was created using an electron microscope.
That is, the inclination angle number distribution graph is set in a lens barrel of a field emission scanning electron microscope with the surfaces of the modified Al ₂ O ₃ layer and the conventional Al ₂ O ₃ layer as polished surfaces. Each of the crystal grains having a hexagonal crystal lattice existing in the measurement range of each polished surface is irradiated with an electron beam with an acceleration voltage of 15 kV at an incident angle of 70 degrees on the polished surface with an irradiation current of 1 nA. The normal line of the (0001) plane, which is the crystal plane of the crystal grain, with respect to the normal line of the polished surface at an interval of 0.1 μm / step in an area of 30 × 50 μm using an electron backscatter diffraction image apparatus Are measured, and based on the measurement results, the measured inclination angles within the range of 45 to 90 degrees are divided into the pitches of 0.25 degrees among the measured inclination angles. Created by aggregating the frequencies existing in It was.

In the inclination angle number distribution graphs of the various Al ₂ O ₃ layers obtained as a result, as shown in Tables 6 and 8, the modified Al ₂ O ₃ layers of the present coated cutting chips 1 to 13 are (0001 ) The distribution of the measured inclination angle of the surface shows the highest peak in the inclination angle section within the range of 83 to 90 degrees, and the total of the frequencies existing within the range of 83 to 90 degrees is the inclination angle distribution graph. While the inclination angle distribution graph occupying a ratio of 45% or more of the entire frequency is shown, the conventional Al ₂ O ₃ layer of the conventional coated cutting tips 1 to 13 has a measured inclination angle distribution of (0001) plane of 45. An inclination angle distribution graph in which the maximum peak is not present in the range of ˜90 degrees, the highest peak is not present, and the sum of the frequencies existing in the range of 80 to 90 degrees is 30% or less of the entire frequency. It was a thing.
Tables 6 and 8 show the inclination angle distribution graphs of the total inclination angles existing in the inclination angle sections in the range of 83 to 90 degrees in the above-mentioned various inclination angle distribution graphs of the Al ₂ O ₃ layers. The percentage of the total was shown.
2 is an inclination angle number distribution graph of the modified Al ₂ O ₃ layer of the coated cutting tip 1 of the present invention, and FIG. 3 is an inclination showing an inclination angle classification of the conventional Al ₂ O ₃ layer of the conventional coated cutting tip 1. It is an angle number distribution graph.

  Moreover, when the thickness of the constituent layer of the hard coating layer of the present invention coated cutting chips 1 to 13 and the conventional coated cutting chips 1 to 13 obtained as a result was measured using a scanning electron microscope (longitudinal section measurement) , Each showed an average layer thickness (average value of 5-point measurement) substantially the same as the target layer thickness.

Next, for the above-described coated cutting chips 1 to 13 of the present invention and various types of coated cutting chips of the conventional coated cutting chips 1 to 13, all of them are screwed to the tip of the tool steel tool with a fixing jig,
Work material: JIS · SCM440 lengthwise equidistant 4 vertical grooved round bar,
Cutting speed: 370 m / min. ,
Incision: 1.5mm,
Feed: 0.2 mm / rev. ,
(Along with cutting conditions A), intermittent high-speed cutting test of alloy steel (normal cutting speed is 200 m / min.),
Work material: JIS / FC250 round bar,
Cutting speed: 420 m / min. ,
Incision: 3mm,
Feed: 0.3 mm / rev. ,
In the above condition (referred to as cutting condition B), continuous dry high-speed cutting test of cast iron (normal cutting speed is 250 m / min.),
Work material: JIS / S30C round bar,
Cutting speed: 330 m / min. ,
Incision: 1.5mm,
Feed: 0.2 mm / rev. ,
Under the above conditions (referred to as cutting condition C), a continuous dry high-speed cutting test (normal cutting speed is 170 m / min.) Of carbon steel is performed. The cutting time until reaching 0.3 mm, which is regarded as a standard for the service life, was measured. The measurement results are shown in Table 9.

From the results shown in Tables 6 to 9, the coated cutting tips 1 to 13 of the present invention have a modified Al ₂ O ₃ layer, which is the upper layer of the hard coating layer, in an inclination angle number distribution graph of the (0001) plane. , The highest peak exists in the inclination angle section in the range of 83 to 90 degrees, and the total of the frequencies existing in the range of 83 to 90 degrees is a ratio of 45% or more of the entire degrees in the inclination angle frequency distribution graph In this case, the wear resistance is further improved, and the rake face portion and the flank face portion including at least the cutting edge ridge portion of the modified Al ₂ O ₃ layer are represented by Ra. : Residual tensile stress in the hard coating layer is remarkably reduced by the hard coating layer residual stress reduction pattern that is polished to a surface roughness of 0.2 μm or less and irradiated with a laser beam over the entire polished surface. As a result, coupled with the improvement in chipping resistance, even when cutting steel and cast iron under high-speed conditions, chipping does not occur and excellent wear resistance is exhibited. The upper layer of the hard coating layer is non-biased within the range of 45 to 90 degrees of the measured inclination angle of the (0001) plane, has no highest peak, and exists within the range of 83 to 90 degrees. In the conventional coated cutting tips 1 to 13 composed of the conventional Al ₂ O ₃ layer showing the inclination angle frequency distribution graph in which the total frequency is 30% or less of the entire frequency, all of the conventional Al ₂ O ₃ layers It is clear that wear of the hard coating layer is remarkably accelerated under high-speed cutting conditions due to the lack of wear resistance, and the service life is reached in a relatively short time.

  As described above, the coated cutting tip of the present invention further includes continuous cutting and intermittent cutting under normal conditions of various types of low alloy steel, carbon steel and other general steels, and gray cast iron and other normal cast irons. Needless to say, since it exhibits excellent wear resistance and excellent cutting performance over a long period of time without occurrence of chipping even in high-speed cutting, it is possible to improve the performance of cutting equipment and save labor in cutting. It can respond satisfactorily to the reduction in cost, energy saving, and cost reduction.

It is a schematic diagram illustrating a measurement range of the inclination angle of the crystal grains (0001) plane in the Al ₂ O ₃ layer constituting the upper layer of the hard coating layer. It is an inclination angle number distribution graph of the (0001) plane of the modified Al ₂ O ₃ layer constituting the hard coating layer of the present coated cutting tip 1. It is an inclination angle number distribution graph of the (0001) plane of the conventional Al ₂ O ₃ layer constituting the hard coating layer of the conventional coated cutting tip 1. It is a schematic perspective view of this invention coating cutting tip which formed the hard coating layer residual stress reduction pattern as an Example by laser beam irradiation formation. FIG. 5 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reducing pattern as an embodiment other than FIG. 4 is formed by laser beam irradiation. FIG. 6 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reduction pattern as an embodiment other than FIGS. 4 and 5 is formed by laser beam irradiation. FIG. 7 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reducing pattern as an embodiment other than FIGS. 4 to 6 is formed by laser beam irradiation. FIG. 8 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reducing pattern as an embodiment other than FIGS. 4 to 7 is formed by laser beam irradiation. FIG. 9 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reducing pattern as an embodiment other than FIGS. FIG. 10 is a schematic perspective view of a coated cutting tip of the present invention in which a hard coating layer residual stress reduction pattern as an embodiment other than FIGS. 4 to 9 is formed by laser beam irradiation. It is a schematic perspective view which shows the state which formed the abrasive material layer in the whole surface of the hard coating layer. It is a schematic perspective view which shows the state after giving wet blast in the state which formed the abrasive material layer. It is a schematic perspective view of the conventional coated cutting tip.

Claims (1)

On the entire rake face and flank face including the cutting edge ridge line portion of the cermet base composed of tungsten carbide base cemented carbide or titanium carbonitride base cermet,
(1) The lower layer is formed of one or more of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer, and carbonitride oxide layer, all formed by chemical vapor deposition. And a Ti compound layer having an overall average layer thickness of 3 to 20 μm,
(2) The upper layer has an α-type crystal structure in the state of chemical vapor deposition and has an average layer thickness of 1 to 15 μm,
In the cutting throwaway tip made of surface-coated cermet formed by vapor-depositing the hard coating layer composed of (1) and (2) above,
(A) Using the field emission scanning electron microscope, the aluminum oxide layer is irradiated with an electron beam on each crystal grain having a hexagonal crystal lattice existing in the measurement range of the surface polished surface, and the method of the polished surface is performed. The inclination angle formed by the normal line of the (0001) plane which is the crystal plane of the crystal grain is measured with respect to the line, and the measurement inclination angle within the range of 45 to 90 degrees out of the measurement inclination angles is set to 0. When divided into 25-degree pitches and represented in an inclination angle number distribution graph obtained by summing up the frequencies existing in each area, the highest peak exists in the inclination angle area within the range of 83 to 90 degrees. The modified aluminum oxide layer showing a tilt angle number distribution graph in which the sum of the frequencies existing in the range of 83 to 90 degrees occupies a ratio of 45% or more of the entire frequency in the tilt angle number distribution graph,
Consisting of
(B) on the entire surface of the modified aluminum oxide layer, which is the upper layer of the hard coating layer,
(B-1) The lower layer has an average layer thickness of 0.1 to 3 μm, and
Composition formula: TiO _x ,
, The central part in the thickness direction is measured with an Auger spectrometer, and the atomic ratio is
X: 1.2 to 1.7,
Satisfying titanium oxide layer,
(B-2) The upper layer has an average layer thickness of 0.05 to 2 μm, and
Composition formula: TiN _1-Y (O) _Y ,
(Where (O) indicates diffused oxygen from the titanium oxide layer), the central portion in the thickness direction is also measured with an Auger spectroscopic analyzer, and the atomic ratio is
Y: 0.01 to 0.4
Satisfying titanium oxynitride layer,
In a state where the abrasive layer constituted by (b-1) and (b-2) is formed by vapor deposition,
(B-3) In wet blasting, as a spraying abrasive, a polishing liquid containing 15 to 60% by mass of aluminum oxide fine particles in a proportion of the total amount with water is sprayed,
Modified aluminum oxide constituting the upper layer of the hard coating layer in the presence of the ground titanium oxide particles in the lower layer, the ground titanium nitride oxide particles in the upper layer, and the aluminum oxide particles as the spray abrasive The rake face portion and the flank face portion including at least the cutting edge ridge portion of the layer are polished, and the surface roughness of these polished surfaces is measured based on the compliant standard JIS B0601-1994, Ra: 0.2 μm or less,
(C) Further, either the rake face or the flank face of the polished surface of the modified aluminum oxide layer, or any one of the single basic shape mark and the collective mark of the single basic shape mark over the entire surface of both surfaces. Or a hard coating layer residual stress reduction pattern in which the single basic shape mark is a dug-down surface in which one of the constituent layers of the hard coating layer is exposed. That irradiation formation,
Surface-coated cermet cutting throwaway tip that exhibits excellent wear resistance with a hard coating layer in high-speed cutting.

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