JP4984513B2 - Manufacturing method of surface-coated cermet cutting tool that exhibits excellent chipping resistance in high-speed cutting of difficult-to-cut materials - Google Patents

Description

In the present invention, the hard coating layer has excellent high temperature hardness and heat resistance, superior high temperature strength, and superior surface smoothness, and an even higher temperature strength than the inherent high temperature strength. Therefore, it is possible to generate high heat when cutting difficult-to-cut materials (work materials) such as stainless steel, high manganese steel, and mild steel, which have high chip viscosity and are easily welded to the tool surface. Even when performed under the accompanying high-speed cutting conditions, the work material and the chips are heated to a high temperature, and the viscosity and weldability are further increased. As a result, the cutting resistance against the surface of the hard coating layer is increased. Nevertheless, the high temperature strength and surface smoothness of the hard coating layer significantly suppresses the occurrence of chipping (small chipping) of the hard coating layer, and exhibits excellent wear resistance over a long period of time. Covered cermet cutting tool (hereinafter, referred to as coated cermet tool) a method of manufacturing a.

Conventionally, generally, as a coated cermet tool, a base made of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet (hereinafter collectively referred to as a tool base) On the surface)
(A) Ti carbide (hereinafter referred to as TiC) layer, nitride (hereinafter also referred to as TiN) layer, carbonitride (hereinafter referred to as TiCN) layer formed by chemical vapor deposition of the lower layers. 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,
(B) The upper layer shows an α-type crystal structure in a state where chemical vapor deposition is formed, and using a field emission scanning electron microscope, as shown in the schematic explanatory diagrams in FIGS. Each crystal grain having a hexagonal crystal lattice existing within the measurement range of the polished surface is irradiated with an electron beam, and the crystal plane of the (0001) plane of the crystal grain is normal to the surface polished surface. The inclination angle formed by the normal line is measured, and among the measurement inclination angles, the measurement inclination angle within the range of 0 to 45 degrees is divided for each pitch of 0.25 degrees, and the frequency existing in each division is determined. In the inclination angle number distribution graph obtained by aggregation, as illustrated in FIG. 5, the highest peak is present in the inclination angle section within the range of 0 to 10 degrees, and the frequency is within the range of 0 to 10 degrees. Is a ratio of 45% or more of the total frequency in the slope angle distribution graph. Mel inclination angle frequency distribution shows a graph, and reforming α-type aluminum oxide layer having an average layer thickness of 1 to 20 [mu] m (hereinafter, shown in the reforming α type the Al ₂ O ₃ layer),
A coated cermet tool is known which is formed by vapor-depositing the hard coating layer composed of (a) and (b) above, and this coated cermet tool is used for high-speed cutting of work materials such as various steels and cast irons. Used for processing.

In addition, the modified α-type Al ₂ O ₃ layer constituting the hard coating layer of the above-described coated cermet tool, first, in a normal chemical vapor deposition apparatus,
Reaction gas composition - by _{volume%, AlCl 3: 1~5%,} CO 2: 5~10%, HCl: 0.3~3%, CH 3 CN: 0.02~0.1%, NO: 0. 02~0.4%, _{H 2:} remainder,
Reaction atmosphere temperature: 800 to 900 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-2 hours
In conditions, preferably as the Al ₂ O ₃ thin film (hereinafter, Al referred ₂ O ₃ or thin) species thin with an average layer thickness of 0.02~0.5μm is formed and the Al ₂ O ₃ or thin On top of the same conditions as the conventional α-type Al ₂ O ₃ layer forming condition, that is, in a normal chemical vapor deposition apparatus,
Reaction gas composition - by _{volume%, AlCl 3: 1~5%,} CO 2: 0.5~10%, HCl: 0.3~3%, H 2 S: 0.02~0.4%, H 2 :remaining,
Reaction atmosphere temperature: 950-1100 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Is formed by at conditions depositing α-type the Al ₂ O ₃ layer, high-temperature hardness is a result formed modified α type the Al ₂ O ₃ layer, which is superior comprising the α-type the Al ₂ O ₃ layer itself In addition, the conventional α-type Al ₂ O ₃ layer is illustrated in FIG. 6 as compared with the conventional α-type Al ₂ O ₃ layer without deteriorating the heat resistance. As shown, it is also known that the measured inclination angle distribution of the (0001) plane shows an unbiased inclination angle number distribution graph within the range of 0 to 45 degrees.

Further, as described above, the above-mentioned modified α-type Al ₂ O ₃ layer has a sharp maximum peak at a specific position of the inclination angle division graph in the inclination angle number distribution graph, and this sharp highest peak is indicated on the horizontal axis of the graph. The height appearing in the tilt angle section changes depending on the reaction atmosphere temperature and the reaction atmosphere pressure when forming the Al ₂ O ₃ seed thin film, and the tilt angle section position on the horizontal axis of the graph also changes depending on the CH ₃ CN content of the reaction gas. It is also known to do.
JP-A-2005-205586

  The performance and automation of cutting machines in recent years have been remarkable. On the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting. Accordingly, cutting speed has been increased and types of work materials have been increased. Although there is a tendency that a general-purpose coated carbide tool not limited to the above is widely desired, in the above-mentioned conventional coated cermet tool, this is applied to general steel such as low alloy steel and carbon steel, as well as ductile cast iron and gray cast iron. There is no problem when it is used for high-speed machining of ordinary cast iron, but this is particularly difficult to cut materials such as stainless steel, high manganese steel, and mild steel that have high chip viscosity and are easily welded to the tool surface. When the cutting material is used under high-speed cutting conditions with high heat generation, the work material and the chips are heated to a high temperature and the viscosity and weldability are further increased. Cutting resistance against the surface of the hard coating layer increases rapidly, but chipping occurs at the cutting edge due to insufficient high-temperature strength of the Ti compound layer that constitutes the lower layer of the hard coating layer. In addition, since the surface smoothness of the hard coating layer affects the occurrence of chipping, the service life is reached in a relatively short time.

Therefore, the present inventors pay attention to the TiCN layer of the Ti compound layer (hereinafter referred to as the conventional TiCN layer), which constitutes the hard coating layer of the conventional coated cermet tool, from the above viewpoint, As a result of research to develop a coated cermet tool that does not cause chipping under the high-speed cutting conditions of the above difficult-to-cut materials, further improving the high-temperature strength of this,
(A) The above-described conventional TiCN layer is formed by a normal chemical vapor deposition apparatus.
Reaction gas composition - by _{volume%, TiCl 4: 2~10%,} CH 3 CN: 0.5~3%, N 2: 10~30%, H 2: remainder,
Reaction atmosphere temperature: 850-950 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
However, prior to the formation of the conventional TiCN layer,
Reaction gas composition - by _{volume%, TiCl 4: 0.2~1%,} C 3 H 6 ( _{methylethylene): 1~5%, N 2:} 20~40%, H 2: remainder,
Reaction atmosphere temperature: 700 to 800 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-3 hours
In this condition, a TiCN thin film (hereinafter referred to as a seed thin film) is desirably formed as a seed thin film with an average layer thickness of 0.02 to 0.5 μm, and the above-described conventional TiCN layer formation conditions are formed on the seed thin film. When the TiCN layer is formed under the same conditions, the TiCN layer at the time of formation is significantly affected by the crystal arrangement of the seed thin film, so that the TiCN layer is sufficiently historyd. The modified TiCN layer) has a much higher high-temperature strength than the conventional TiCN layer described above, and exhibits excellent chipping resistance even in high-speed cutting of difficult-to-cut materials with high cutting resistance. To be like that.

(B) About the modified TiCN layer and the conventional TiCN layer constituting the lower layer of the hard coating layer of the above coated cermet tool,
Using a field emission scanning electron microscope, as shown in the schematic explanatory diagrams of FIGS. 1A and 1B, electron beams are individually applied to crystal grains having a cubic crystal lattice existing within the measurement range of the surface polished surface. Irradiate and measure the tilt angle formed by the normal of the {112} plane which is the crystal plane of the crystal grain with respect to the normal of the surface-polished surface. When the measured inclination angle within the range is divided for each pitch of 0.25 degrees and the inclination angle number distribution graph is created by summing up the frequencies existing in each division, the conventional TiCN layer is formed as shown in FIG. As shown in FIG. 2, the distribution of measured inclination angles of the {112} plane shows an unbiased inclination angle number distribution graph in the range of 0 to 45 degrees, whereas the modified TiCN layer is shown in FIG. As illustrated, the sharpest peak appears at a specific position in the tilt angle section, and this -Loop highest peak height appearing in the tilt angle sections of the graph the horizontal axis is changed by a reaction atmosphere temperature and reaction atmosphere pressure during the seed film formation, TiCl tilt angle division position also reactive gases graph horizontal axis ₄ Change according to content.

(C) As described above, when forming the seed thin film for forming the modified TiCN layer, the TiCl ₄ content in the reaction gas is set to 0.2 to 1%, whereby the inclination angle number distribution of the modified TiCN layer is set. In the graph, the sharp maximum peak appears in the range of 0 to 10 degrees of the tilt angle section, and the reaction atmosphere temperature is set to 700 to 800 ° C. and the reaction atmosphere pressure is set to 3 to 13 kPa, thereby the above 0 to 10 degrees. In this case, according to the test results, TiCl ₄ shows a TiCl ₄ distribution graph in which the sum of the frequencies existing in the range of 45% represents a ratio of 45% or more of the entire frequency in the tilt angle frequency distribution graph. Even in the case where the content of Ti is less than 0.2% or the content exceeds 1%, the gradient angle distribution position of the maximum peak is 10 degrees in the gradient angle distribution graph of the modified TiCN layer in any case. The As a result, the modified TiCN layer can no longer be provided with an excellent high-temperature strength, and the reaction atmosphere temperature and the reaction atmosphere pressure are about 800 ° C. even if the temperature is less than 700 ° C. Even if the temperature exceeds ℃, even if the pressure is less than 3 kPa or exceeds 13 kPa, the frequency ratio existing in the range of 0 to 10 degrees in the gradient angle distribution graph of the modified TiCN layer is less than 45%. In this case as well, the high temperature strength cannot be improved further.

(D) On the other hand, the modified α-type Al ₂ O ₃ layer constituting the upper layer of the hard coating layer of the above-mentioned coated cermet tool has a relatively rough vapor deposition surface, and this causes a particularly high speed of the above difficult-to-cut material. In the cutting process, chipping is likely to occur at the cutting edge portion. Therefore, on the entire surface of the modified α-type Al ₂ O ₃ layer,
In a state in which a titanium nitride (hereinafter referred to as TiN) layer is formed by vapor deposition under normal conditions, for example, conditions shown in Table 3 and an average layer thickness of 0.5 to 5 μm, using a normal chemical vapor deposition apparatus. ,
When a polishing liquid containing 15 to 60% by mass of aluminum oxide fine particles (hereinafter referred to as Al ₂ O ₃ fine particles) is injected as a polishing material by wet blasting as a proportion of the total amount with water, the above TiN The layer (hereinafter referred to as TiN abrasive layer) is pulverized and pulverized by the Al ₂ O ₃ fine particles, becomes TiN fine particles and acts as an abrasive in the presence of the Al ₂ O ₃ fine particles, and is an upper layer of the hard coating layer. It will be polishing the surface of the modified α type the Al ₂ O ₃ layer constituting the surface of the reformed α-type the Al ₂ O ₃ layer after the results polishing, based on compliance JIS · B0601-1994 In measurement (the following surface roughnesses are all measured values based on such standards), Ra is smoothed to a surface roughness of 0.2 μm or less. Type Al ₂ O ₃ layer surface is Ra: 0.2 μm or less When the above-mentioned coated cermet tool smoothed to a surface roughness of 5 mm was subjected to high-speed cutting of a difficult-to-cut material, 350 m / min. Even at a cutting speed exceeding 1, the effect of suppressing the occurrence of chipping at the cutting edge is sufficiently exerted, and greatly contributes to the improvement of chipping resistance of the hard coating layer.

(E) In this case, without forming the TiN abrasive layer on the surface of the modified α-type Al ₂ O ₃ layer, the wet abrasive is also used as a spray abrasive to form water. Even when the polishing liquid containing 15 to 60% by mass of Al ₂ O ₃ fine particles as a proportion of the total amount is directly sprayed and polished, the surface of the modified α-type Al ₂ O ₃ layer is Ra: 0 Only the surface roughness of 3 to 0.6 μm is polished, and the resulting surface roughness Ra: 0.3 to 0.6 μm constitutes the upper layer with the modified α-type Al ₂ O ₃ layer. Even when a coated cermet tool in which one of the layers is composed of the modified TiCN layer is used, the cutting speed is 350 m / min. It is impossible to satisfactorily suppress chipping at the cutting edge by high-speed cutting of difficult-to-cut materials exceeding the limit.

(F) As described above, together with the upper layer of the hard coating layer is composed of the reformed α-type the Al ₂ O ₃ layer, the rake face including at least cutting ridge of the reformed α-type the Al ₂ O ₃ layer A Ti compound comprising the above modified TiCN layer in which the surface roughness of these polished surfaces is Ra: 0.2 μm or less and one of the lower layers is further improved in high-temperature strength by polishing the portion and the flank portion The coated cermet tool composed of a layer has a high-temperature strength that makes the hard coating layer remarkably excellent, especially in high-speed cutting of difficult-to-cut materials in which extremely high cutting resistance is applied to the cutting edge, and the modified α type Since the Al ₂ O ₃ layer has excellent surface smoothness, it exhibits excellent chipping resistance and exhibits excellent wear resistance over a long period of time (a) to (f) The research results shown were obtained.

This invention was made based on the above research results,
(1) Using a chemical vapor deposition apparatus on the surface of the tool base composed of WC-based cemented carbide or TiCN-based cermet,
(A) As a lower layer,
(A-1) one or more of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, and a TiCNO layer; and
(A-2) a reaction gas composition - by _{volume%, TiCl 4: 0.2~1%,} C 3 H 6 ( _{methylethylene): 1~5%, N 2:} 20~40%, H 2: remainder,
Reaction atmosphere temperature: 700 to 800 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-3 hours
Through a seed thin film formed with an average layer thickness of 0.02 to 0.5 μm under the above conditions, and with an average layer thickness of 2.5 to 15 μm as a proportion of the total amount with the seed thin film, and field emission Using a scanning electron microscope, irradiate each crystal grain having a cubic crystal lattice existing within the measurement range of the surface polished surface with an electron beam, and the crystal of the crystal grain with respect to the normal of the surface polished surface Measuring the inclination angle formed by the normal of the {112} plane, which is a surface, and dividing the measurement inclination angle within the range of 0 to 45 degrees out of the measurement inclination angles every pitch of 0.25 degrees; In the slope angle distribution graph obtained by summing up the frequencies existing in each section, the highest peak exists in the tilt angle section within the range of 0 to 10 degrees, and the frequencies existing in the range of 0 to 10 degrees. Is a ratio of 45% or more of the total frequency in the slope angle distribution graph A modified TiCN layer showing an inclination angle number distribution graph occupying
And a Ti compound layer having an overall average layer thickness of 3 to 20 μm,
(B) as the upper layer, the reaction gas composition - by _{volume%, AlCl 3: 1~5%,} CO 2: 5~10%, HCl: 0.3~3%, CH 3 CN: 0.02~0. 1%, NO: 0.02~0.4%, H 2: remainder,
Reaction atmosphere temperature: 800 to 900 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-2 hours
A state in which an average layer thickness of 1 to 20 μm is formed by chemical vapor deposition through a seed thin film formed with an average layer thickness of 0.02 to 0.5 μm under the conditions of The surface-polished surface is irradiated with an electron beam on each crystal grain having a hexagonal crystal lattice present in the measurement range of the surface-polished surface using a field emission scanning electron microscope. The inclination angle formed by the normal line of the (0001) plane which is the crystal plane of the crystal grain is measured, and the measurement inclination angle within the range of 0 to 45 degrees is measured among the measurement inclination angles. In the inclination angle number distribution graph obtained by summing up the frequencies existing in each division, with the highest peak existing in the inclination angle division in the range of 0 to 10 degrees, and dividing every pitch of 0.25 degrees, The sum of the frequencies existing within the range of 0 to 10 degrees is the number of inclination angles. It shows an inclination angle frequency distribution graph in a proportion of more than 45% of the total power in the graph, and reforming α type the Al ₂ O ₃ layer having an average layer thickness of 1 to 20 [mu] m,
The hard coating layer composed of the above (a) and (b) is formed by vapor deposition,
(2) Next, on the entire surface of the modified α-type Al ₂ O ₃ layer, which is the upper layer of the hard coating layer,
In a state where the TiN abrasive layer is formed by chemical vapor deposition with an average layer thickness of 0.5 to 5 μm,
In wet blasting, as a spraying abrasive, a polishing liquid containing 15 to 60% by mass of Al ₂ O ₃ fine particles in a proportion of the total amount with water is sprayed,
And Al ₂ O ₃ milled TiN fine made by grinding atomized by atomization of injection is TiN abrasive layer is injection abrasive described above, in the presence of Al ₂ O ₃ fine as injection abrasive, the hard coating layer The rake face portion and the flank face portion including at least the cutting edge ridge line portion of the modified α-type Al ₂ O ₃ layer constituting the upper layer of the steel are polished, and the surface roughness of these polished surfaces is set to Ra: 0.2 μm or less. Become,
It has a feature in a method for producing a coated cermet tool that exhibits excellent chipping resistance in a hard coating layer in high-speed cutting of difficult-to-cut materials.

Hereinafter, the reason why the hard coating layer, the abrasive layer, and the Al ₂ O ₃ fine particles of the polishing liquid used in the wet blasting in the method for producing the coated cermet tool of the present invention are numerically limited as described above will be described.
(A) Hard coating layer (a-1) Ti compound layer (lower layer)
The Ti compound layer itself has high-temperature strength, and the presence of the Ti compound layer makes the hard coating layer have high-temperature strength, and in addition to the tool base and the modified α-type Al ₂ O ₃ layer that is the upper layer. Also has an action that contributes to improving the adhesion of the hard coating layer to the tool substrate, but if the total average layer thickness is less than 3 μm, the above-mentioned action cannot be fully exerted, while the total When the average layer thickness exceeds 20 μm, high-speed cutting with high heat generation is likely to cause thermoplastic deformation, which causes uneven wear. Therefore, the total average layer thickness is set to 3 to 20 μm. .

(A-2) Modified TiCN layer (lower layer)
As described above, when forming the seed thin film of the modified TiCN layer, by setting the content of TiCl _{4 in} the reaction gas to 0.2 to 1%, the sharpest peak is the inclination angle in the inclination angle number distribution graph. When the reaction atmosphere temperature is 700 to 800 ° C. and the reaction atmosphere pressure is 3 to 13 kPa, the total number of frequencies existing in the range of 0 to 10 degrees can be obtained. Then, a modified TiCN layer showing an inclined angle number distribution graph occupying a ratio of 45% or more of the entire frequency in the inclined angle number distribution graph is formed, and as a result, the modified TiCN layer is further improved in high temperature. However, if the average layer thickness is less than 2.5 μm, the hard coating layer cannot be provided with the desired excellent high-temperature strength, while the average layer thickness is 1 Exceeds [mu] m, easily heat the plastic deformation which causes partial wear is generated, since it becomes worn accelerates, determined the average layer thickness and 2.5～15Myuemu.

(A-3) Modified α-type Al ₂ O ₃ layer (upper layer)
The modified α-type Al ₂ O ₃ layer has an inclination angle distribution graph in which the sharpest peak appears in the range of 0 to 10 degrees of the inclination angle section and exists within the range of 0 to 10 degrees. Shows an inclination angle distribution graph that occupies a ratio of 45% or more of the entire frequency in the inclination angle distribution distribution graph. As a result, it has excellent high-temperature strength and improves chipping resistance. The excellent high-temperature hardness and heat resistance of the Al ₂ O ₃ layer itself contributes to improving the wear resistance of the hard coating layer. However, if the average layer thickness is less than 1 μm, the hard coating layer has sufficient wear resistance. On the other hand, when the average layer thickness exceeds 20 μm and becomes too thick, chipping tends to occur. Therefore, the average layer thickness is set to 1 to 20 μm.

(B) TiN abrasive layer As described above, TiN abrasive layer during wet blasting, the Al ₂ O ₃ fine formulated as injection abrasive in the polishing liquid milled micronized, the Al ₂ O ₃ becomes TiN fine Acts as an abrasive in the presence of fine particles and polishes the surface of the modified α-type Al ₂ O ₃ layer constituting the upper layer of the hard coating layer. In this case, if the average layer thickness is less than 0.5 μm When the average layer thickness exceeds 5 μm, the proportion of pulverized TiN fine particles at the time of wet blasting is too small to sufficiently exert the polishing function. The balance with the ₂ O ₃ fine particles is lost and becomes relatively large. In this case as well, the polishing function is suddenly lowered. In either case, the surface of the α-type Al ₂ O ₃ layer is set to Ra: 0. Polish to a surface roughness of 2 μm or less It because it becomes impossible to determine the average layer thickness and 0.5 to 5 [mu] m.

(C) Polishing Al ₂ O ₃ Fine Particles In the polishing liquid Al ₂ O ₃ fine particles, the modified α-type Al ₂ O ₃ layer coexists with the ground TiN fine particles of the TiN abrasive layer during wet blasting. There is an action to polish the surface, but even if the ratio is less than 15% by mass or more than 60% by mass with respect to the total amount with water, the polishing function will rapidly decrease, so that ratio Was determined to be 15 to 60% by mass.

The coated cermet tool manufactured by the method of the present invention has a modified TiCN layer having a higher high-temperature strength as one of the Ti compound layers constituting the lower layer of the hard coating layer, and also a higher temperature of the upper layer. The modified α-type Al ₂ O ₃ layer has excellent high-temperature strength in addition to hardness and heat resistance, and the surface of the modified α-type Al ₂ O ₃ layer is Ra: 0.2 μm or less. By polishing to the surface roughness, cutting of difficult-to-cut materials (work materials) such as stainless steel, high manganese steel, and mild steel, which have high chip viscosity and easily weld to the tool surface, generates high heat. Even if the work material and chips are heated to a high temperature and the viscosity and weldability are further increased, and the cutting resistance against the surface of the hard coating layer is increased accordingly, Excellent high temperature strength of hard coating The chipping of the hard coating layer is remarkably suppressed by the degree and the smooth surface roughness, and excellent wear resistance is exhibited.

Next, the method for producing a coated cermet tool according to 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, TaN powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders were blended into the composition shown in Table 1, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and pressed into a green compact with a predetermined shape at a pressure of 98 MPa. The green compact was vacuum sintered at a predetermined temperature in the range of 1370 to 1470 ° C. for 1 hour in a vacuum of 5 Pa. After sintering, the cutting edge portion was R: 0.07 mm honing Made of WC-based cemented carbide with a throwaway tip shape defined as CNMG12041 in the ISO standard in the form of having a tool mounting through hole in the center by processing Tool bases A to F were produced, respectively.

In addition, as raw material powders, TiCN (mass ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder, all having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and pressed into a compact at a pressure of 98 MPa. The green compact was 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 was subjected to a honing process of R: 0.07 mm, Made of TiCN-based cermet with a throwaway tip shape specified as CNMN12041 in the ISO standard, with no holes attached to the tool body by clamping with clamp pieces To form a tool substrate a~f.

Next, a Ti compound layer is formed as a lower layer of the hard coating layer on the surfaces of the tool bases A to F and the tool bases a to f using a normal chemical vapor deposition apparatus under the conditions shown in Table 3. In this case, when forming the modified TiCN layer of the Ti compound layer, first, the seed thin film a to the target modified TiCN layer corresponding to the conditions shown in Table 4, that is, the target modified TiCN layer determined based on the test results k is formed in the combination shown in Table 7, and subsequently, the modified TiCN layer is formed under the same conditions as those for forming the conventional TiCN layer shown in Table 3 as described above. First, the conditions shown in Table 5, that is, any one of the seed thin films A to K corresponding to the target modified α-type Al ₂ O ₃ layer determined based on the test results are also shown. 7 and the combination shown in Subsequently, with the modified α-type Al ₂ O ₃ layer as the upper layer under the same conditions as those for forming the conventional α-type Al ₂ O ₃ layer shown in Table 3 as described above, the target layer thickness shown in Table 7 is used. Further, a TiN abrasive layer is formed under the TiN layer forming conditions shown in Table 3, and the target layer thickness is also shown in Table 7,
Subsequently, wet blasting was performed under the blasting conditions shown in Table 6 and in the combinations shown in Table 7, and for the tool bases A to F, a TiN abrasive layer was present around the center hole for tool attachment. In addition, for the above-described tool bases a to f, the modified α-type Al ₂ O ₃ layer (with the TiN abrasive layer present on the clamp piece abutting surface portion (rake face center portion)) ( The rake cermet tools 1 to 13 of the present invention were manufactured by polishing the rake face and the flank face including the cutting edge ridge line portion of the upper layer to the surface roughness similarly shown in Table 7.

  For comparison purposes, as shown in Table 8, the conventional TiCN layer is used under the conditions shown in Table 3 instead of the modified TiCN layer constituting the lower layer of the hard coating layer of the coated cermet tools 1 to 13 of the present invention. Conventionally coated cermet tools 1 to 13 were produced under the same conditions except that the above-described TiN abrasive layer formation and surface polishing treatment by wet blasting were not performed.

Next, a field emission scanning electron microscope was used for the modified TiCN layer and the conventional TiCN layer, and further the modified α-type Al ₂ O ₃ layer constituting the hard coating layer of the above-described coated cermet tool of the present invention and the conventional coated cermet tool. Thus, an inclination angle number distribution graph was created.
That is, the tilt angle number distribution graph shows the column of the field emission scanning electron microscope in a state where the surfaces of the modified TiCN layer, the conventional TiCN layer, and the modified α-type Al ₂ O ₃ layer are polished surfaces. A cubic crystal lattice (TiCN) or hexagonal crystal existing in the measurement range of the surface polished surface with an electron beam with an acceleration voltage of 15 kV and an irradiation current of 1 nA at an incident angle of 70 degrees on the polished surface. Irradiate each crystal grain having a crystal lattice (Al ₂ O ₃ ), and use an electron backscatter diffraction image apparatus to make a 30 × 50 μm region normal to the surface polished surface at an interval of 0.1 μm / step. On the other hand, the inclination angle formed by the normal of the {112} plane (TiCN layer) or (0001) plane (Al ₂ O ₃ layer) which is the crystal plane of the crystal grain is measured, and based on the measurement result, The range of 0 to 45 degrees of the measured tilt angle With dividing the measured tilt angle for each pitch of 0.25 degrees in, created by aggregating the frequencies present in each segment.

In the gradient angle distribution graphs of various modified TiCN layers and conventional TiCN layers obtained as a result, and various modified α-type Al ₂ O ₃ layers, the {112} plane or the (0001) plane shows the highest peak. Tables 9 and 10 show the ratios of the tilt angle numbers existing in the tilt angle sections and the tilt angle sections within the range of 0 to 10 degrees to the tilt angle numbers of the entire tilt angle distribution graph, respectively.

In the above-mentioned various inclination angle number distribution graphs, as shown in Tables 9 and 10, respectively, the modified TiCN layer and the modified α-type Al ₂ O ₃ layer of the coated cermet tool of the present invention are both {112} plane and The distribution of the measured inclination angle of the (0001) plane has the highest peak in the inclination angle section in the range of 0 to 10 degrees, and the ratio of the number of inclination angles existing in the inclination angle section in the range of 0 to 10 degrees is In contrast to the inclination angle number distribution graph of 45% or more, the modified α-type Al ₂ O ₃ layer of the conventional coated cermet tool similarly has a measured inclination angle distribution on the (0001) plane of 0 to 10 degrees. An inclination angle number distribution graph in which the highest peak appears in the inclination angle section in the range and the ratio of the inclination angle numbers existing in the inclination angle section in the range of 0 to 10 degrees is 45% or more is shown in the conventional TiCN. All layers are measured in the {112} plane Inclination in which the angle distribution is unbiased within the range of 0 to 45 degrees, the highest peak is not present, and the ratio of the number of inclination angles existing in the inclination angle section within the range of 0 to 10 degrees is 30% or less. An angle number distribution graph was shown.
2 is an inclination angle distribution graph of the modified TiCN layer of the coated cermet tool 3 of the present invention, FIG. 3 is an inclination angle distribution graph of the conventional TiCN layer of the conventional coated cermet tool 3, and FIG. indicating invention coated cermet tool 3 of the modified α type the Al ₂ O ₃ layer inclination angle frequency distribution graph in FIG. 6, the conventional coated cermet tool 3 of the modified α type the Al ₂ O ₃ layer inclination angle frequency distribution graphs, respectively Is.

  Further, regarding the above-described coated cermet tools 1 to 13 and the conventional coated cermet tools 1 to 13, the lower layer and the upper layer of the hard coating layer are formed by using an electron beam microanalyzer (EPMA) and an Auger spectroscopic analyzer. When observed using (observing the longitudinal section of the layer), it is confirmed that both have substantially the same composition as the target composition, and the thickness of the constituent layer of the hard coating layer of these coated cermet tools, When measured using a scanning electron microscope (same longitudinal section measurement), all showed an average layer thickness (average value of 5-point measurement) substantially the same as the target layer thickness.

Next, in the state where both of the above-described coated cermet tools 1 to 13 and the conventional coated cermet tools 1 to 13 are attached to the tip of the tool steel tool,
Work material: JIS / SUS316 round bar,
Cutting speed: 400 m / min,
Incision: 1.5mm,
Feed: 0.3mm / rev,
Cutting time: 6 minutes
Dry high-speed continuous cutting test of stainless steel under the above conditions (cutting condition A) (normal cutting speed is 200 m / min),
Work material: JIS-SMn438H lengthwise equidistant 4 round grooved round bars,
Cutting speed: 390 m / min,
Incision: 1.5mm,
Feed: 0.2mm / rev,
Cutting time: 7 minutes
High-manganese steel dry high-speed intermittent cutting test under normal conditions (cutting condition B) (normal cutting speed is 180 m / min),
Work material: JIS / SS330 lengthwise equidistant 4 round bars with flutes,
Cutting speed: 430 m / min,
Cutting depth: 2mm,
Feed: 0.2mm / rev,
Cutting time: 7 minutes
A dry high-speed intermittent cutting test (normal cutting speed is 200 m / min) of mild steel under the above conditions (cutting condition C), and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 11.

From the results shown in Tables 7 to 11, according to the present invention coated cermet tools 1 to 13, one of the Ti compound layers as the lower layer of the hard coating layer has an inclination angle of {112} plane of 0 to 0. An inclination angle distribution graph showing the highest peak in the inclination angle section within the range of 10 degrees and the total ratio of the frequencies existing in the inclination angle section range of 0 to 10 degrees occupying 45% or more, which is much higher It is composed of a modified TiCN layer with improved strength, and further exhibits the highest peak in the inclination angle section within the range of 0 to 10 degrees of the inclination angle of the (0001) plane, and the inclination angle section range of 0 to 10 degrees. 2 shows an inclination angle frequency distribution graph in which the total ratio of frequencies existing in the tube occupies 45% or more. As a result, in addition to excellent high-temperature hardness and heat resistance, modified α-type Al ₂ that has improved high-temperature strength The upper layer is composed of the O ₃ layer, and The surface of the rake face portion and the flank face portion including at least the cutting edge ridge line portion of the modified α-type Al ₂ O ₃ layer is polished to a surface roughness of Ra: 0.2 μm or less, which contributes to improvement of chipping resistance. Combined with this, even in high-speed cutting of difficult-to-cut materials that add extremely high cutting resistance to the cutting edge, chipping at the cutting edge is remarkably suppressed, while exhibiting excellent wear resistance. One of the Ti compound layers, which is the lower layer of the hard coating layer, has an inclination angle number distribution in which the distribution of measured inclination angles on the {112} plane is unbiased within the range of 0 to 45 degrees, and there is no highest peak. In the conventional coated cermet tools 1 to 13 which are composed of a conventional TiCN layer showing a graph and the upper layer is composed of a modified α-type Al ₂ O ₃ layer having low surface smoothness, all are high-speed cutting of difficult-to-cut materials In processing, the high temperature strength of the hard coating layer is insufficient. Therefore, it is obvious that chipping occurs at the cutting edge portion in combination with the outer layer having low surface smoothness, and the service life is reached in a relatively short time.

As described above, the coated cermet tool manufactured by the method of the present invention is not only required to have high-temperature strength and surface smoothness that are excellent in hard coating layers as well as high-speed cutting of various steels and cast iron. Even in high-speed cutting of cutting materials, the hard coating layer exhibits excellent chipping resistance and exhibits excellent wear resistance over a long period of time. It can cope with energy saving and cost reduction sufficiently satisfactorily.

It is a schematic explanatory drawing which shows the measurement range of the inclination angle of the {112} plane of the crystal grain in the TiCN layer which comprises the lower layer of a hard coating layer. It is an inclination angle number distribution graph of the {112} plane of the modified TiCN layer constituting the lower layer of the hard coating layer of the coated cermet tool 3 of the present invention. It is the inclination angle number distribution graph of the {112} plane of the conventional TiCN layer which constitutes the lower layer of the hard coating layer of the conventional coated cermet tool 3. It is a schematic diagram illustrating a measurement range of the inclination angle of the crystal grains (0001) plane in the hard coating layer α type the Al ₂ O ₃ layer constituting the. It is an inclination angle number distribution graph of the (0001) plane of the modified α-type Al ₂ O ₃ layer constituting the upper layer of the hard coating layer of the coated cermet tool 3 of the present invention. 6 is a graph showing the distribution of the number of inclination angles of the (0001) plane of the modified α-type Al ₂ O ₃ layer constituting the upper layer of the hard coating layer of the conventional coated cermet tool 3.

Claims (1)

(1) Using a chemical vapor deposition apparatus on the surface of the tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
(A) As a lower layer,
(A-1) one or more of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer, and carbonitride layer, and
(A-2) a reaction gas composition - by _{volume%, TiCl 4: 0.2~1%,} C 3 H 6 ( _{methylethylene): 1~5%, N 2:} 20~40%, H 2: remainder,
Reaction atmosphere temperature: 700 to 800 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-3 hours
An average layer of 2.5 to 15 μm in a proportion of the total amount with the titanium carbonitride seed thin film through a titanium carbonitride thin film formed as a seed thin film with an average layer thickness of 0.02 to 0.5 μm under the conditions of Using a field emission scanning electron microscope, irradiate an electron beam to each crystal grain having a cubic crystal lattice existing within the measurement range of the surface polished surface to obtain a normal to the surface polished surface. On the other hand, the inclination angle formed by the normal line of the {112} plane which is the crystal plane of the crystal grain is measured, and the measurement inclination angle within the range of 0 to 45 degrees out of the measurement inclination angles is 0.25 degrees. In the inclination angle number distribution graph formed by summing up the frequencies existing in each section, the highest peak exists in the inclination angle section in the range of 0 to 10 degrees, and the above 0 to 10 The total number of frequencies existing in the range of degrees is the slope angle distribution graph Modified titanium carbonitride layer showing an inclination angle frequency distribution graph occupying a ratio of 45% or more of the entire frequency in
And a Ti compound layer having a total average layer thickness of 3 to 20 μm,
(B) as the upper layer, the reaction gas composition - by _{volume%, AlCl 3: 1~5%,} CO 2: 5~10%, HCl: 0.3~3%, CH 3 CN: 0.02~0. 1%, NO: 0.02~0.4%, H 2: remainder,
Reaction atmosphere temperature: 800 to 900 ° C.
Reaction atmosphere pressure: 3 to 13 kPa,
Deposition time: 0.5-2 hours
The film is formed with an average layer thickness of 1 to 20 μm through the aluminum oxide thin film formed as a seed thin film with an average layer thickness of 0.02 to 0.5 μm under the above conditions in the proportion of the total amount with the aluminum oxide seed thin film. In the state of chemical vapor deposition, an α-type crystal structure is shown, and a field emission scanning electron microscope is used to irradiate each crystal grain having a hexagonal crystal lattice within the measurement range of the surface polished surface with an electron beam. Then, 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 surface-polished surface, and is within a range of 0 to 45 degrees out of the measurement inclination angle. In the inclination angle distribution graph that is obtained by classifying the measured inclination angles in each of the pitches of 0.25 degrees and summing up the frequencies existing in each section, the inclination angle section in the range of 0 to 10 degrees is the highest. There is a peak and the 0-10 degree The total of the frequencies present in 囲内 is modified α-type aluminum oxide layer shows an inclination angle frequency distribution graph in a proportion of 45% or more of the total power at the inclination angle frequency distribution graph,
The hard coating layer composed of the above (a) and (b) is formed by vapor deposition,
(2) Next, on the entire surface of the modified α-type aluminum oxide layer, which is the upper layer of the hard coating layer,
In a state where an abrasive layer composed of a titanium nitride layer having an average layer thickness of 0.5 to 5 μm is formed by chemical vapor deposition,
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,
The upper layer of the hard coating layer is formed under the coexistence of pulverized titanium nitride fine particles obtained by pulverizing and atomizing aluminum oxide fine particles, which are spray abrasives, and aluminum oxide fine particles as spray abrasives. The rake face portion and the flank face portion including at least the cutting edge ridge line portion of the modified α-type aluminum oxide layer to be constituted 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,
A method of manufacturing a surface-coated cermet cutting tool that exhibits excellent chipping resistance in a high-speed cutting of difficult-to-cut materials characterized by

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