JPWO2017057456A1 - Coated tool - Google Patents

Abstract

The coating tool according to one aspect includes a base and a coating layer positioned on the surface of the base, and further includes a first surface, a second surface, a third surface, and a cutting edge, and the coating layer includes the first layer, The first layer contains titanium carbonitride and is located closer to the substrate than the second layer, the second layer contains aluminum oxide, and X-ray diffraction of the third surface Regarding the orientation coefficient Tc (hkl) calculated based on the peaks attributed to each crystal plane detected in the analysis, the orientation coefficient Tc (330) is larger than the orientation coefficient Tc (110).

Description

  This embodiment relates to a coated tool having a coating layer on the surface of a substrate.

  2. Description of the Related Art Conventionally, a coating tool in which a single layer or a plurality of coating layers is located on the surface of a substrate is known. In recent years, the efficiency of cutting has been improved, and the above-described coated tool is increasingly used for cutting in which a large impact such as heavy interrupted cutting is applied to the cutting edge. Under such severe cutting conditions, since a large impact is applied to the coating layer, chipping and peeling of the coating layer are likely to occur. Therefore, it is required to improve the fracture resistance of the coating layer.

  As techniques for improving fracture resistance in a coated tool, techniques described in Patent Documents 1 to 5 are known. In Patent Document 1 (Japanese Patent No. 6-316758), the grain size and the layer thickness of the aluminum oxide layer are optimized, and the organization coefficient (Texture Coefficient) on the (012) plane is 1.3 or more. It is disclosed that. Patent Document 2 (Japanese Patent Laid-Open No. 2003-025114) discloses that the organization coefficient on the (012) plane of the aluminum oxide layer is 2.5 or more. In Patent Document 3 (Japanese Patent Laid-Open No. 10-204439), an aluminum oxide layer located immediately above an intermediate layer is formed by laminating two or more layers showing different X-ray diffraction patterns. Is disclosed.

  Patent Document 4 (Japanese Patent Laid-Open No. 2013-132717) discloses that the orientation coefficient of the (006) plane of the aluminum oxide layer is increased to 1.8 or more, and the peak intensity between the (104) plane and the (110) plane. It is disclosed that the ratio I (104) / I (110) is controlled within a predetermined range. Patent Document 5 (Japanese Unexamined Patent Application Publication No. 2009-202264) describes the peak intensity ratio I (104) / I (012) between the (104) plane and the (012) plane of the aluminum oxide layer, below the aluminum oxide layer. It is disclosed that the second surface is larger than the first surface.

  In recent years, higher wear resistance and fracture resistance are required for coating layers. In particular, there is a demand for further improving the wear resistance of the aluminum oxide layer by suppressing minute chipping that is likely to occur in the aluminum oxide layer, thereby suppressing the abrasion that proceeds as a trigger.

  The coating tool according to one aspect includes a base and a coating layer positioned on the surface of the base, and further includes a first surface, a second surface opposite to the first surface, the first surface, and the first surface. A third surface located between the second surface and a cutting edge at an intersection of the first surface and the second surface; and the covering layer has a first layer and a second layer. The first layer contains a titanium carbonitride layer and is located closer to the base than the second layer, and the second layer contains aluminum oxide and the base more than the first layer. Located far from.

In the X-ray diffraction analysis of the third surface, (HKL) is all the crystal planes of (012), (104), (110), (113), (024), (116) and (330). (HKL), any one crystal plane is (hkl), the peak intensity of the peak attributed to each crystal plane detected on the third plane is I, and the standard diffraction intensity of each crystal plane is I _0. And the orientation coefficient Tc (hkl) is represented by {I (hkl) / I ₀ (hkl)} / [(1/7) × Σ {I (HKL) / I ₀ (HKL)}] Tc (330) is larger than the orientation coefficient Tc (110).

It is a schematic perspective view of the covering tool which concerns on one Embodiment. It is a schematic sectional drawing of the coating tool shown in FIG.

  A cutting tool (hereinafter simply referred to as a tool) 1 will be described with reference to the drawings as a coated tool according to an embodiment. As shown in FIG. 2, the tool 1 includes a base 2 and a coating layer 3 positioned on the surface of the base 2. The coating layer 3 has a first layer 4 containing titanium carbonitride and a second layer 5 containing aluminum oxide, and has a structure in which a plurality of layers are laminated. The first layer 4 is located closer to the base 2 than the second layer 5, and the second layer 5 is located farther from the base 2 than the first layer 4. At this time, the second layer 5 may be in contact with the first layer 4, and another layer may be located between the first layer 4 and the second layer 5.

  The configuration of the first layer 4 is not particularly limited, but the first layer 4 in the present embodiment has a configuration in which two layers are stacked. Specifically, a region 4a containing MT (Moderate Temperature) -titanium carbonitride located on the base 2 side, and a region 4b containing HT-titanium carbonitride located above this region Are stacked. As thickness of the 1st layer 4, it can set to 6-13 micrometers, for example. At this time, the particle diameter of MT-titanium carbonitride can be set to 0.08 μm or less, for example.

  The configuration of aluminum oxide in the second layer 5 is not particularly limited, but has an α-type crystal structure in the present embodiment. The thickness of the second layer 5 can be set to 1 to 15 μm, for example. In particular, when the thickness is 3 to 8 μm, the balance between adhesion and wear resistance in the second layer 5 can be improved. At this time, the particle size of aluminum oxide in the α-type crystal structure can be set to 1 μm or less, for example.

  As shown in FIG. 1, the tool 1 includes a first surface 6, a second surface 7 positioned opposite to the first surface 6, and a third surface positioned between the first surface 6 and the second surface 7. 8 and has a square plate shape. Therefore, in the present embodiment, the first surface 6 and the third surface 8 intersect. Hereinafter, the first surface 6 may be referred to as an upper surface, the second surface 7 as a lower surface, and the third surface 8 as a side surface in accordance with FIG.

  At least a part of the third surface 8 functions as a so-called flank. Further, at least a part of the first surface 6 has a function as a so-called rake face that scrapes off chips generated by cutting.

  The cutting edge 11 is located at least at a part of the ridge where the first surface 6 and the third surface 8 intersect. The cutting edge 11 is generally located at a portion where the rake face and the flank face intersect. The workpiece can be cut by applying the cutting edge 11 to the workpiece. The coated tool of the present embodiment is a cutting tool, but the coated tool can be applied to various uses such as an excavating tool and a blade in addition to the cutting tool. Reliability.

  The tool 1 of the present embodiment is detected in the X-ray diffraction analysis of the third surface 8, and the orientation factor Tc (330) is calculated with respect to the orientation factor Tc (hkl) calculated based on the intensity of the peak attributed to each crystal plane. ) Is larger than the orientation coefficient Tc (110).

Here, the orientation coefficient Tc is a value represented by {I (hkl) / I ₀ (hkl)} / [(1/7) × Σ {I (HKL) / I ₀ (HKL)}]. At this time, all of the crystal planes of (012), (104), (110), (113), (024), (116) and (330) are set to (HKL), and any one crystal plane is ( hkl). The intensity of the peak attributed to each crystal face detected on the third face 8 is I, and the standard diffraction intensity of each crystal face is I ₀ . I ₀ (HKL) and I ₀ (hkl) are JCPDS card numbers. The numerical value described in 00-010-0173 may be used.

In this embodiment, Σ {I (HKL) / I ₀ (HKL)} is {I (012) / I ₀ (012)} + {I (104) / I ₀ (104)} + {I (110) ) / I ₀ (110)} + {I (113) / I ₀ (113)} + {I (024) / I ₀ (024)} + {I (116) / I ₀ (116)} + {I (330) / I ₀ (330)}.

  Since the orientation coefficient Tc is obtained as a ratio to the standard data defined by the JCPDS card, it can be regarded as an index representing the degree of orientation of each crystal plane.

  According to the present embodiment, the orientation coefficient Tc (330) is larger than the orientation coefficient Tc (110). Thereby, since the crystal structure of the second layer 5 has a specific strain, the wear resistance of the second layer 5 is improved, and the tool 1 can be used over a long period of time.

  This is because when Tc (330) is larger than Tc (110), the toughness of the aluminum oxide particles constituting the second layer 5 is increased, so that the thickness direction of the second layer 5 (perpendicular to the surface of the tool 1). It can be considered that the aluminum oxide crystal constituting the second layer 5 is likely to be squeezed with respect to the impact in the direction. As the toughness of the aluminum oxide particles increases, the resistance to fracture increases. For this reason, it is considered that the minute chipping generated on the surface of the second layer 5 is suppressed and the progress of wear due to the minute chipping can be suppressed.

  When the aspect ratio of the aluminum oxide crystal in the second layer 5 is 3 or more, the aluminum oxide crystal is easily crystallized, so that the toughness of the aluminum oxide particles can be further increased.

  When Tc (330) is 1.1 to 5, the wear resistance of the second layer 5 is particularly high. When Tc (330) is 1.1 or more, the aluminum oxide crystals constituting the second layer 5 are more likely to be further formed, so that the second layer 5 is not easily destroyed. Further, when Tc (330) is 5 or less, the adhesion of the second layer 5 to the layer adjacent to the lower side of the second layer 5 in the coating layer 3 is enhanced, and therefore the second layer 5 may be peeled off. Can be reduced. A particularly desirable range of Tc (330) is 1.1 to 3.

  Moreover, when Tc (110) is 0.1-3, the abrasion resistance of the second layer 5 is enhanced.

  Hereinafter, a method for measuring the orientation coefficient Tc (hkl) in the second layer 5 will be described. The X-ray diffraction analysis of the second layer 5 is measured using an X-ray diffraction analysis apparatus using a general CuKα ray. In determining the peak intensity of each crystal plane of the second layer 5 from the X-ray diffraction chart, the JCPDS card No. The diffraction angle of each crystal plane described in 00-010-0173 is confirmed, the crystal plane of the detected peak is identified, and the peak intensity is measured.

  Moreover, although the peak detected by X-ray diffraction analysis is identified using a JCPDS card, the peak position may be shifted due to residual stress or the like existing in the coating layer 3. Therefore, in order to confirm whether or not the detected peak is the peak of the second layer 5, X-ray diffraction analysis is performed with the second layer 5 polished, and the peak detected before and after polishing is detected. Compare. From this difference, it can be confirmed that it is the peak of the second layer 5.

  Tc (hkl) may be determined by measuring the intensity of the peak attributed to each crystal plane detected when the second layer 5 is subjected to X-ray diffraction analysis from the surface side of the tool 1. First, the coating layer 3 is polished so that the second layer 5 is exposed. When the second layer 5 is the outermost layer in the coating layer 3, polishing is not necessary.

  X-ray diffraction analysis is performed on the coating layer 3 with the second layer 5 exposed. By measuring the peak intensity at each crystal plane obtained by this analysis, the orientation coefficient Tc (hkl) is calculated. In addition, when the coating layer 3 is polished, a part of the second layer 5 (for example, 20% or less of the thickness of the second layer 5) may be removed.

  Polishing may be performed by brush processing using diamond abrasive grains, processing by an elastic grindstone, or blast processing.

  Although the second layer 5 may have a single layer configuration, the second layer 5 in the present embodiment includes a first aluminum oxide layer 5a and a second aluminum oxide layer located on the first aluminum oxide layer 5a. 5b.

  At this time, when the orientation coefficient of the first aluminum oxide layer 5a is Tca (hkl) and the orientation coefficient of the second aluminum oxide layer 5b is Tcb (hkl), Tca (330) is more than Tcb (330). Is smaller, the adhesion of the second layer 5 can be further enhanced.

  This is because when the first aluminum oxide layer 5a and the second aluminum oxide layer 5b have a relatively small Tca (hkl), which is the orientation coefficient of the first aluminum oxide layer 5a located near the substrate 2, This is because the entire second layer 5 is easily deformed, but the difference in thermal expansion coefficient between the second layer 5 and a layer adjacent to the lower side of the second layer 5 is reduced, and the possibility that the second layer 5 is peeled can be reduced.

  Since I (hkl) indicates the intensity of the peak attributed to each crystal plane detected when the second layer 5 is subjected to X-ray diffraction analysis from the surface side of the tool 1, the second layer 5 In the present embodiment in which is a two-layer configuration of the first aluminum oxide layer 5a and the second aluminum oxide layer 5b, Tcb (hkl) and Tc (hkl) have substantially the same value.

  That is, when the second layer 5 is a two-layer configuration of the first aluminum oxide layer 5a and the second aluminum oxide layer 5b and Tca (330) is smaller than Tc (330), the adhesion of the second layer 5 is improved. In other words, it can be further enhanced. The range of Tca (330) is not particularly limited, but can be set to 0.5 to 1.2, for example.

  When the second layer 5 includes the first aluminum oxide layer 5a and the second aluminum oxide layer 5b, the measurement of Tca (hkl) and Tcb (hkl) may be performed as follows.

  First, the coating layer 3 is polished so that the second aluminum oxide layer 5b located on the surface side of the tool 1 is exposed. When the second aluminum oxide layer 5b is the outermost layer in the coating layer 3, polishing is not necessary. X-ray diffraction analysis is performed on the coating layer 3 with the second aluminum oxide layer 5b exposed. By measuring the peak intensity at each crystal plane obtained by this analysis, the orientation coefficient Tcb (hkl) is calculated.

  Next, the second aluminum oxide layer 5b is polished and removed to expose the first aluminum oxide layer 5a. Specifically, according to the thickness of the second aluminum oxide layer 5b, about 60 to 90% of the entire thickness of the second layer 5 is polished to expose the first aluminum oxide layer 5a. Then, X-ray diffraction analysis is performed on the covering layer 3 in a state where the first aluminum oxide layer 5a is exposed. By measuring the peak intensity at each crystal plane obtained by this analysis, the orientation coefficient Tca (hkl) is calculated.

  In the present embodiment, the orientation coefficient on the first surface 6 is Tc1 (hkl). At this time, when Tc1 (330) is smaller than Tc (330), the progress of crater wear on the rake face in the first face 6 can be suppressed.

  The measurement of Tc1 (hkl) may be performed in the same manner as the measurement of Tc (hkl). Specifically, the coating layer 3 is polished so that a portion of the second layer 5 located on the first surface 6 is exposed. X-ray diffraction analysis is performed on the coating layer 3 in a state where the above-described portion in the second layer 5 is exposed. The orientation coefficient Tc1 (hkl) is calculated by measuring the peak intensity at each crystal plane obtained by this analysis.

  When the orientation coefficient Tc1 (104) on the first surface 6 is smaller than the orientation coefficient Tc (104), the progress of crater wear on the rake face in the first surface 6 can be suppressed.

  Further, when the coating layer 3 is located on the first surface 6 and the third surface 8 of the tool 1, the ratio of the orientation coefficient Tc (330) and the orientation coefficient Tc (110) (Tc (330) / Tc ( 110)) is larger than the ratio (Tc1 (330) / Tc1 (110)) between the orientation coefficient Tc1 (330) and the orientation coefficient Tc1 (110), the strain of the second layer 5 on the first surface 6 In addition, since the strain of the second layer 5 on the third surface 8 can be both optimized, the progression of crater wear on the rake face on the first surface 6 can be suppressed, and the resistance on the flank surface on the third surface 8 can be reduced. It is possible to achieve both improved chipping.

  Of the peak intensities I (hkl) attributed to each crystal plane detected in the X-ray diffraction analysis of the third surface 8, one of I (116) and I (104) is the strongest, and I (116 ) And I (104) are the second strongest, the flank wear caused by minute chipping can be suppressed on the third surface 8 having the flank.

The region 4a containing MT-titanium carbonitride constituting the first layer 4 in the coating layer 3 contains acetonitrile (CH ₃ CN) gas as a raw material, and is formed at a relatively low film formation temperature of 780 to 900 ° C. Made of columnar crystals. The region 4b containing HT-titanium carbonitride consists of granular crystals formed at a high film formation temperature of 950 to 1100 ° C.

  In this embodiment, when the region 4b containing HT-titanium carbonitride is viewed in a cross-section along the thickness direction of the coating layer 3, the surface of the region 4b containing HT-titanium carbonitride is directed to the second layer 5. Triangular protrusions that taper off are formed. When such protrusions are provided, the adhesion between the first layer 4 and the second layer 5 is increased, and peeling and chipping of the coating layer 3 can be suppressed.

  The coating layer 3 only needs to have at least the first layer 4 and the second layer 5, but the coating layer 3 in this embodiment has a lower layer 12, an intermediate layer 13, and an upper layer 14 in addition to these layers. doing. The lower layer 12 is located closer to the base 2 than the first layer 4. The intermediate layer 13 is located between the first layer 4 and the second layer 5. The upper layer 14 is located on the second layer 5. Therefore, the coating layer 3 in the present embodiment has a configuration in which the lower layer 12, the first layer 4, the intermediate layer 13, the second layer 5, and the upper layer 14 are laminated in this order.

  Examples of the material for the lower layer 12 include titanium nitride (TiN), titanium carbonitride (TiCN), titanium carbonitride (TiCNO), and chromium nitride (CrN). The lower layer 12 may be composed of only one of these materials, or may be composed of a plurality of these materials. The lower layer 12 may be used to improve the bonding property between the base 2 and the first layer 4, and in such a case, it is also called an underlayer. The thickness of the lower layer 12 can be set to 0.1-1 micrometer, for example.

  The intermediate layer 13 is a layer containing, for example, titanium and oxygen, and specifically includes titanium carbonate (TiCO), titanium oxynitride (TiNO), titanium carbonitride (TiCNO), and aluminum carbonate titanium (TiAlCO). As an example of the material, titanium titanium carbonitride (TiAlCNO) can be given. Although not particularly shown, the intermediate layer 13 may be constituted by two layers, for example, a lower intermediate layer and an upper intermediate layer. When the intermediate layer 13 has the above-described configuration, the aluminum oxide particles constituting the second layer 5 can be easily formed into an α-type crystal structure. The second layer 5 having the α-type crystal structure has high hardness, and can improve the wear resistance of the coating layer 3. The thickness of the intermediate layer 13 can be set to 0.05 to 1 μm, for example.

  The intermediate layer 13 means a layer located between the first layer 4 and the second layer 5 and does not necessarily include the center in the thickness direction of the entire coating layer 3.

  Examples of the material of the upper layer 14 include titanium nitride (TiN), titanium carbonitride (TiCN), titanium carbonitride (TiCNO), and chromium nitride (CrN), as in the lower layer 12. The thickness of the upper layer 14 can be set to 0.1 to 3 μm, for example.

  The thickness of each layer and the crystals constituting each layer can be measured by observing an electron micrograph (scanning electron microscope (SEM) photograph or transmission electron microscope (TEM) photograph) in the cross section of the tool 1. It is. Moreover, in this embodiment, when the ratio of the average crystal width to the length of the target crystal in the thickness direction of the coating layer 3 is 0.3 or less on the average for the crystals constituting each layer of the coating layer 3 Is assumed to be columnar. Moreover, when said ratio exceeds 0.3 on average, the form of the crystal | crystallization shall be granular.

Although it does not specifically limit as a material of the base | substrate 2, For example, a cemented carbide alloy, Ti group cermet, and ceramics are mentioned. As the cemented carbide, for example, a hard phase containing tungsten carbide (WC) and at least one selected from the group consisting of carbides, nitrides, and carbonitrides of Group 4, 5, and 6 metals of the periodic table, Examples thereof include those bonded with a binder phase containing an iron group metal such as cobalt (Co) and nickel (Ni). Examples of the ceramic include silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ ), diamond, and cubic boron nitride (cBN).

  In the case where the substrate 2 is made of cemented carbide or Ti-based cermet among the above materials, the fracture resistance and wear resistance can be improved. Depending on the application, the substrate 2 may be made of a metal such as carbon steel, high-speed steel, or alloy steel.

  Next, a method for manufacturing the coated tool according to the present embodiment will be described with reference to an example of a method for manufacturing the tool 1.

  First, metal powder, carbon powder, and the like are appropriately added to and mixed with an inorganic powder selected from metal carbide, nitride, carbonitride, oxide, and the like. The mixed powder is molded into a predetermined shape using a known molding method to produce a molded body. Examples of the molding method include press molding, cast molding, extrusion molding, and cold isostatic pressing. The base body 2 is produced by firing the molded body in a vacuum or in a non-oxidizing atmosphere. If necessary, the surface of the substrate 2 may be subjected to polishing or honing.

  Next, the coating layer 3 is formed on the surface of the substrate 2 by chemical vapor deposition (CVD).

First, hydrogen (H ₂ ) gas is mixed with 0.5 to 10% by volume of titanium tetrachloride (TiCl ₄ ) gas and 10 to 60% by volume of nitrogen (N ₂ ) gas and used as a reaction gas. A first mixed gas is produced. The first mixed gas is introduced into the chamber, and the lower layer 12 containing titanium nitride (TiN) is formed at a film forming temperature of 800 to 940 ° C. and a pressure in the chamber of 8 to 50 kPa.

Next, in hydrogen (H ₂ ) gas, 0.5 to 10 vol% titanium tetrachloride (TiCl ₄ ) gas, 5 to 60 vol% nitrogen (N ₂ ) gas, and 0.1 to 3 vol% Acetonitrile (CH ₃ CN) gas is mixed to produce a second mixed gas. A region containing MT-titanium carbonitride in the first layer 4 is formed by introducing the second mixed gas into the chamber, setting the film formation temperature to 780 to 880 ° C., and the pressure in the chamber to 5 to 25 kPa.

At this time, the average crystal width of the columnar crystals of titanium carbonitride constituting the first layer is closer to the substrate 2 by increasing the content ratio of acetonitrile (CH ₃ CN) gas in the later stage of film formation than in the initial stage of film formation. The side farther from the base body 2 can be configured to be larger than that.

Next, a region containing HT-titanium carbonitride in the first layer 4 is formed. In this embodiment, hydrogen (H ₂ ) gas is added to 1 to 4% by volume of titanium tetrachloride (TiCl ₄ ) gas, 5 to 20% by volume of nitrogen (N ₂ ) gas, and 0.1 to 10% by volume. A methane (CH ₄ ) gas is mixed to produce a third mixed gas. The third mixed gas is introduced into the chamber, the film formation temperature is 900 to 1050 ° C., the pressure in the chamber is 5 to 40 kPa, and the above region is formed.

Next, the intermediate layer 13 is produced. Hydrogen (H ₂ ) gas, 3 to 15 volume% titanium tetrachloride (TiCl ₄ ) gas, 3 to 10 volume% methane (CH ₄ ) gas, and 0 to 25 volume% nitrogen (N ₂ ) gas Then, 0.5 to 2% by volume of carbon monoxide (CO) gas and 0 to 3% by volume of aluminum trichloride (AlCl ₃ ) gas are mixed to produce a fourth mixed gas. The fourth mixed gas is introduced into the chamber, the film formation temperature is 900 to 1050 ° C., the pressure in the chamber is 5 to 40 kPa, and the intermediate layer 13 is formed.

The intermediate layer 13 may be composed of one layer or may be composed of two or more layers. Note that when the intermediate layer 13 is formed, argon (Ar) gas may be used instead of nitrogen (N ₂ ) gas. In the case of using argon (Ar) gas, fine irregularities can be formed on the surface of the intermediate layer 13, so that it is easy to adjust the growth state of the aluminum oxide crystal in the second layer 5 to be formed next. Become.

  Then, the second layer 5 is formed. When the second layer 5 is formed, an aluminum oxide crystal nucleus may be formed first. When this nucleus is formed, control of Tc (330) becomes easy. In addition, when the nucleus is formed, the growth state of the aluminum oxide crystal in the second layer 5 can be easily changed, so that the Tca (4010) in the second layer 5 can be easily controlled.

Hydrogen (H ₂ ) gas, 5 to 10% by volume aluminum trichloride (AlCl ₃ ) gas, 0.1 to 1% by volume hydrogen chloride (HCl) gas, and 0.1 to 5% by volume carbon dioxide (CO ₂ ) gas is mixed to prepare a fifth mixed gas. The fifth mixed gas is introduced into the chamber, the film formation temperature is set to 950 to 1100 ° C., and the pressure in the chamber is set to 5 to 10 kPa to form the nucleus.

Next, in hydrogen (H ₂ ) gas, 5 to 15% by volume of aluminum trichloride (AlCl ₃ ) gas, 0.5 to 2.5% by volume of hydrogen chloride (HCl) gas, and 0.5 to 5%. A sixth mixed gas is prepared by mixing volume% carbon dioxide (CO ₂ ) gas and 0.1 to 1 volume% hydrogen sulfide (H ₂ S) gas. The sixth mixed gas is introduced into the chamber, the film formation temperature is 950 to 1100 ° C., the pressure in the chamber is 5 to 20 kPa, and the second layer 5 is formed.

  At this time, the inflow / stop of HCl gas may be repeated every 0.1 to 2 minutes using a pulse current. In this case, since the growth state of the aluminum oxide crystal in the second layer 5 can be easily adjusted, Tc (330) can be easily made larger than Tc (110).

  At this time, for example, the relationship between Tc (330) and Tc1 (330) is obtained by polishing one of the portion located on the first surface 6 and the portion located on the third surface 8 in the second layer 5. Can be adjusted.

Then, an upper layer (TiN layer) is formed. A seventh mixed gas is produced by mixing hydrogen (H ₂ ) gas with 0.1 to 10% by volume of titanium tetrachloride (TiCl ₄ ) gas and 10 to 60% by volume of nitrogen (N ₂ ) gas. . The seventh mixed gas is introduced into the chamber, the film formation temperature is set to 960 to 1100 ° C., the pressure in the chamber is set to 10 to 85 kPa, and the seventh mixed gas is formed.

  Thereafter, if necessary, the portion where the cutting edge 11 is located on the surface of the coating layer 3 is polished. When such a polishing process is performed, since the welding of the work material to the cutting edge 11 is easily suppressed, the tool 1 is further excellent in fracture resistance.

  First, it contains 6% by mass of metallic cobalt powder having an average particle size of 1.2 μm, 0.5% by mass of titanium carbide powder having an average particle size of 2 μm, and 5% by mass of niobium carbide powder having an average particle size of 2 μm. Then, a mixed powder in which the balance is tungsten carbide powder having an average particle diameter of 1.5 μm is prepared. A compact is produced by molding the above mixed powder into a tool shape (CNMG120408) using press molding. After the binder was removed from the molded body, it was fired in a vacuum of 1500 ° C. and 0.01 Pa for 1 hour to prepare a substrate 2. Thereafter, the fabricated base 2 was subjected to brushing, and the portion that becomes the cutting edge 11 in the tool 1 was subjected to R honing.

  Next, the coating layer 3 was formed on the substrate 2 under the film formation conditions shown in Table 1 by chemical vapor deposition (CVD). Sample No. About 1-10, after forming a 2nd layer into a film, the grinding | polishing process was performed to the part located in the 3rd surface 8. FIG. In Tables 1 and 2, each compound is represented by a chemical symbol.

  In Table 1, the inflow method of HCl gas is described as “pulse” and “normal”. “Pulse” means a method in which inflow / stop of HCl gas is repeated every other minute using a pulse current. “Normal” means a method in which HCl gas is introduced without being stopped using a pump.

For the sample, first, X-ray diffraction analysis using CuKα rays was performed on the portion of the coating layer 3 located on the first surface 6 without polishing the coating layer 3. Based on this analysis and standard data defined by the JCPDS card, the (330) plane, (110) plane, (104) of Al ₂ O _{3 having} a partial α-type crystal structure located on the first plane 6 in the coating layer 3 The orientation coefficient Tc (hkl) of each crystal plane of the plane and (116) plane was calculated.

  Next, X-ray diffraction analysis by CuKα rays is performed on the portion of the coating layer 3 located on the third surface 8 without polishing the coating layer 3, and the peak on the surface side of the second layer (in the table, Identification of the surface side or surface side peak) and the intensity of each peak were measured. As for the peak on the surface side, the strongest peak and the second strongest peak are confirmed, and the orientation coefficient Tcb of each crystal plane of the (330) plane, the (110) plane, the (104) plane, and the (116) plane is confirmed. (Hkl) was calculated. At this time, Tcb (hkl) is equivalent to Tc (hkl).

  Moreover, in the part located in the 3rd surface 8 in the coating layer 3, about 60 to 90% is grind | polished with respect to the whole thickness of a 2nd layer, and the thickness of the 2nd layer 5 is set to 10 to 40% before grinding | polishing. After that, an X-ray diffraction analysis is performed, and a peak on the substrate 2 side (described as “substrate side” in the table) is measured in a state where a portion on the substrate 2 side in the second layer is left. The intensity of each peak was measured. Using the peak intensity of each obtained peak, the orientation coefficient Tca (hkl) of each crystal plane of (330) plane, (110) plane, (104) plane, and (116) plane was calculated.

  In addition, the said X-ray-diffraction measurement measured about three arbitrary samples, and evaluated it with the average value. Moreover, the fracture surface of the said tool 1 was observed with the scanning electron microscope (SEM), and the thickness of each layer was measured. The results are shown in Tables 2-4.

Next, using the obtained cutting tool 1, a continuous cutting test and an intermittent cutting test were performed under the following conditions to evaluate the wear resistance and fracture resistance. The results are shown in Table 4.
(Continuous cutting conditions)
Work Material: Chromium Molybdenum Steel (SCM435)
Tool shape: CNMG120408
Cutting speed: 300 m / min Feeding speed: 0.3 mm / rev
Cutting depth: 1.5mm
Cutting time: 25 minutes Others: Use of water-soluble cutting fluid Evaluation item: The edge honing portion is observed with a scanning electron microscope, and the width of flank wear on the flank face of the first surface 6 in the actually worn portion Then, the width of crater wear on the rake face in the third face 8 was measured.
(Intermittent cutting conditions)
Work Material: Chromium Molybdenum Steel Four Grooved Steel (SCM440)
Tool shape: CNMG120408
Cutting speed: 300 m / min Feeding speed: 0.3 mm / rev
Cutting depth: 1.5mm
Others: Use of water-soluble cutting fluid Evaluation item: Measures the number of impacts leading to defects.

  According to the results in Tables 1 to 4, the sample No. Tc (330) is the same as or smaller than Tc (110). In Nos. 9 to 11, the wear progressed quickly and the second layer 5 was easily peeled off by impact.

  On the other hand, the sample No. Tc (330) is larger than Tc (110). In 1 to 8, minute chipping of the second layer 5 was suppressed, and almost no peeling occurred. In particular, sample Nos. With Tc (330) of 1.1-5. In 1 to 5, the width of flank wear was also small.

  In addition, the sample No. Tc1 (330) is smaller than Tc (330). In Nos. 1 to 6, sample widths of crater wear were small and Tca (330) was smaller than Tcb (330). In 1-4, the width of flank wear was small.

  Further, in the peak on the surface side of the second layer 5a, the sample No. 1 in which the (104) plane and the (116) plane consist of the first and second highest peaks. Regarding 1 to 7, the width of flank wear was small and the number of impacts was also increased. In addition, the sample No. Tc1 (104) is smaller than Tc (104). In 1 to 6, crater wear was small and the number of impacts was increased.

  Further, the sample No. 1 in which the ratio (Tc (330) / Tc (110)) is larger than the ratio (Tc1 (330) / Tc1 (110)). In Nos. 1 to 6, the crater wear was further reduced, and the number of impacts until the cutting edge 11 was broken increased.

1 ... Cutting tool (tool)
2 ... Base 3 ... Covering layer 4 ... 1st layer 5 ... 2nd layer 6 ... 1st surface 7 ... 2nd surface 8 ... 3rd surface 11 .... Blade 12 ·· Lower layer 13 ·· Intermediate layer 14 ·· Upper layer

Claims (7)

The coating tool includes a substrate and a coating layer located on the surface of the substrate,
Further, the covering tool includes a first surface, a second surface positioned opposite to the first surface, a third surface positioned between the first surface and the second surface, and the first surface. And a cutting blade at the intersection of the third surface,
The covering layer has a first layer and a second layer,
The first layer contains titanium carbonitride and is located closer to the substrate than the second layer;
The second layer contains aluminum oxide and is located farther from the substrate than the first layer;
In the X-ray diffraction analysis of the third surface,
(012), (104), (110), (113), (024), (116) and (330) are all crystal planes (HKL), and any one crystal plane is (hkl).
The intensity of the peak attributed to each crystal plane detected on the third surface is I,
The standard diffraction intensity of each crystal plane is I ₀ ,
When the orientation coefficient Tc (hkl) is represented by {I (hkl) / I ₀ (hkl)} / [(1/7) × Σ {I (HKL) / I ₀ (HKL)}],
A coated tool having an orientation coefficient Tc (330) larger than the orientation coefficient Tc (110).   The coated tool according to claim 1, wherein the orientation coefficient Tc (330) is 1.1 to 5. The second layer has a first aluminum oxide layer and a second aluminum oxide layer located on the first aluminum oxide layer,
The coated tool according to claim 1 or 2, wherein the orientation coefficient Tca (330) in the first aluminum oxide layer is smaller than the orientation coefficient Tcb (330) in the second aluminum oxide layer.   The coated tool according to any one of claims 1 to 3, wherein the orientation coefficient Tc1 (330) is smaller than the orientation coefficient Tc (330) when the orientation coefficient on the first surface is Tc1 (hkl).   The coated tool according to claim 4, wherein the orientation coefficient Tc1 (104) is smaller than the orientation coefficient Tc (104).   The ratio (Tc (330) / Tc (110)) between the orientation coefficient Tc (330) and the orientation coefficient Tc (110) is the ratio between the orientation coefficient Tc1 (330) and the orientation coefficient Tc1 (110) ( The coated tool according to claim 4 or 5, which is larger than Tc1 (330) / Tc1 (110)). Of the I of the peak intensity attributed to each crystal plane detected in the X-ray diffraction analysis of the third surface, one of I (116) and I (104) is the strongest, and I (116) and I ( The coated tool according to any one of claims 1 to 6, wherein the other of 104) is the second strongest.

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