Coating layer-formed body

Abstract

Provided is a coating layer-formed body in which a coating layer has high peeling resistance. The coating layer includes: a plurality of crystals containing Ti and N; a first region containing a plurality of first crystals belonging to the plurality of crystals; and a second region located closer to a substrate with respect to the first region and containing a plurality of second crystals belonging to the plurality of crystals. The crystal grain size of the second crystals is smaller than the crystal grain size of the first crystals.

Description

Coating layer forming body

[0001] This disclosure relates to a coating layer forming body.

[0002] An example of a coating layer forming body is the wear-resistant TiN film forming body disclosed in Patent Document 1.

[0003] Japanese Patent Publication No. 2009-299142

[0004] A coating layer forming body according to one aspect of the present disclosure comprises a substrate and a coating layer located above the substrate, wherein the coating layer has a plurality of crystals containing Ti (titanium) and N (nitrogen), a first region including a plurality of first crystals belonging to the plurality of crystals, and a second region located closer to the substrate than the first region and including a plurality of second crystals belonging to the plurality of crystals, wherein the grain size of the second crystals is smaller than the grain size of the first crystals.

[0005] This is a cross-sectional view showing the structure of the coating layer forming body according to Embodiment 1 of this disclosure. This is the first example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure observed by an SEM (scanning electron microscope). This is the first example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure observed by a TEM (transmission electron microscope). This is the first example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure analyzed by EBSD (electron backscattering analysis). This is the second example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure observed by an SEM. This is the second example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure observed by a TEM. This is the second example of a photograph of a cross-section of the coating layer forming body according to Embodiment 1 of this disclosure analyzed by EBSD. This is a plan view showing the results of scratch tests on test samples A, B, and C. This is a graph showing the results of scratch tests on test samples A, B, and C. This is a table showing the results of scratch tests on test samples A to G. (111) A graph showing the results of the scratch test for orientation ratio and (111) crystallite size. (111) A graph showing the results of the scratch test for orientation ratio and coating layer thickness. (111) A graph showing the results of the scratch test for crystallite size and coating layer thickness. (111) Another graph showing the results of the scratch test for crystallite size and coating layer thickness. (111) A graph showing the results of the scratch test for hardness and coating layer thickness. Another graph showing the results of the scratch test for hardness and coating layer thickness. (111) A graph showing the results of the scratch test for coating layer thickness. (111) A graph showing the results of the scratch test for hardness of the coating layer. (111) A graph showing the results of the scratch test for orientation ratio. (111) A graph showing the results of the scratch test for crystallite size. A table showing the conditions for the scratch test to obtain the results in Figures 17 to 20. N in the method for manufacturing a coating layer formed body according to Embodiment 1 of the present disclosure ２This is a graph showing the (111) orientation ratio with respect to Ar. This is a graph showing the (111) orientation ratio with respect to Ar bombardment time in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a graph showing the (111) orientation ratio with respect to film formation time in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a graph showing the (111) orientation ratio with respect to film formation rate in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a graph showing the (111) orientation ratio with respect to bias voltage in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a graph showing the (111) orientation ratio with respect to film formation temperature in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a graph showing the (111) orientation ratio with respect to total pressure in the manufacturing method of the coating layer forming body according to Embodiment 1 of this disclosure. This is a table showing the manufacturing conditions of the coating layer forming body according to Embodiment 1 of this disclosure to obtain the results in Figures 22 to 28. This is a cross-sectional view showing the configuration of the coating layer forming body according to Embodiment 2 of this disclosure. This is the first example of a photograph of a cross-section of the coating layer forming body according to Embodiment 2 of this disclosure observed by SEM. This is the first example of a photograph of a cross-section of a coated layer-forming body according to Embodiment 2 of this disclosure, observed by TEM. This is the first example of a photograph of a cross-section of a coated layer-forming body according to Embodiment 2 of this disclosure, analyzed by EBSD. This is the second example of a photograph of a cross-section of a coated layer-forming body according to Embodiment 2 of this disclosure, observed by SEM. This is the second example of a photograph of a cross-section of a coated layer-forming body according to Embodiment 2 of this disclosure, observed by TEM. This is the second example of a photograph of a cross-section of a coated layer-forming body according to Embodiment 2 of this disclosure, analyzed by EBSD. A method for identifying the first-oriented crystal and the second-oriented crystal is shown. A method for calculating the average crystal grain size is shown. A method for calculating the average crystal grain size is shown. An AIP apparatus is shown.

[0006] A coating-forming body with high resistance to peeling of the coating layer is expected.

[0007] According to one aspect of this disclosure, a coating layer-forming body with high resistance to peeling of the coating layer can be realized.

[0008] The following describes the forms for implementing this disclosure. For the sake of convenience, components having the same function as those described earlier will be denoted by the same reference numerals, and their descriptions may not be repeated.

[0009] [Embodiment 1] Figure 1 is a cross-sectional view showing the configuration of a coating layer forming body 101 according to Embodiment 1 of the present disclosure.

[0010] Figure 2 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, observed by SEM. Figure 3 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, observed by TEM. Figure 4 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, analyzed by EBSD.

[0011] Figure 5 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, observed by SEM. Figure 6 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, observed by TEM. Figure 7 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 1 of this disclosure, analyzed by EBSD.

[0012] Two types of cross-sectional images observed by TEM are shown: Photograph P, and Photograph Q, which is twice the magnification of Photograph P.

[0013] The coating layer forming body 101 comprises a base material 1 and a coating layer 2 located above the base material 1. The coating layer forming body 101 may be used in a way that the coating layer 2 slides against the surface of other components. Examples of applications for the coating layer forming body 101 include liners for artificial hip joints, femoral components for artificial knee joints, and end plates for artificial intervertebral discs.

[0014] Metal can be used as an example of the material of base material 1. Specific examples of the material of base material 1 include steel, titanium metal, and titanium alloy.

[0015] The coating layer 2 comprises a plurality of crystals 3 containing Ti and N, a first region 5 containing a plurality of first crystals 4 belonging to the plurality of crystals 3, and a second region 7 located closer to the substrate 1 than the first region 5 and containing a plurality of second crystals 6 belonging to the plurality of crystals 3. The coating layer 2 may be any film containing Ti and N, and may be a so-called TiN film. However, it is not limited to this, and the coating layer 2 may be at least one of a TiC film, a TiNbN film, a ZrN film, and a TiAlN film.

[0016] The grain size of the second crystal 6 is smaller than the grain size of the first crystal 4. The fact that the grain size of the second crystal 6 is smaller than the grain size of the first crystal 4 can also be interpreted as the largest grain size among the multiple second crystals 6 being smaller than the largest grain size among the multiple first crystals 4. The fact that the grain size of the second crystal 6 is smaller than the grain size of the first crystal 4 can also be interpreted as the smallest grain size among the multiple second crystals 6 being smaller than the smallest grain size among the multiple first crystals 4.

[0017] As a result, when the surface of the coating layer 2 is rubbed, the first crystal 4 located on the surface of the coating layer 2 has a relatively large grain size, thus reducing the occurrence of chipping, which can be the starting point for the peeling of the coating layer 2. The second crystal 6 located at the interface with the substrate 1 has a relatively small grain size, thus increasing the bonding force with the substrate 1, and reducing the extent to which the peeling of the coating layer 2 progresses to the interface with the substrate 1 when cracks occur inside the coating layer 2. Therefore, a coating layer forming body 101 with high peeling resistance of the coating layer 2 can be realized. By having the second crystal 6 at the interface between the substrate 1 and the coating layer 2, the propagation of cracks near the interface can be suppressed, and scratch peeling resistance can be improved. It is thought that the second crystal 6 at the interface can be formed by shortening the ion bombardment time before the formation of the coating layer 2, thereby reducing the surface activity energy of the substrate 1 and making initial crystal growth difficult. The second crystal 6 may also affect the growth of the first crystal 4 that exists on top of it.

[0018] The average grain size of the multiple second crystals 6 may be smaller than the average grain size of the multiple first crystals 4. Here, the average grain size may be a value calculated from crystal grains visible from a cross-sectional image obtained by cutting the coating layer 2 in the thickness direction. The average grain size of the multiple second crystals 6 may be 0.14 μm or less. The average grain size of the multiple first crystals 4 may be 0.14 μm or more. The ratio obtained by dividing the average grain size of the multiple first crystals 4 by the average grain size of the multiple second crystals 6 may be 1.4 or more. In the coating layer formed body 101 in which the improvement in the peel resistance of the coating layer 2 was actually confirmed, the second region 7 was defined as having a thickness of 1 μm from the interface between the substrate 1 and the coating layer 2, and the grain size of the multiple crystals 3 included in the second region 7 was calculated by image analysis. The average value was 0.09 μm. On the other hand, when the grain size of the multiple crystals 3 included in the first region 5 was calculated by image analysis, the average value was 0.22 μm. It can be seen that if the average grain size of the multiple second crystals 6 is 0.14 μm or less, while the average grain size of the multiple first crystals 4 is 0.14 μm or more, an improvement in the peel resistance of the coating layer 2 can be obtained.

[0019] The thickness of the coating layer 2 may be 3 μm or more and 20 μm or less. If the thickness of the coating layer 2 is less than 3 μm, even if various other configurations of the coating layer forming body 101 are applied, the coating layer 2 may be too thin and have low peel resistance. Specifically, if the coating layer 2 is too thin, the Young's modulus of the substrate 1 is lower than that of the coating layer 2, causing the substrate 1 to deform during sliding, and tensile stress to act inside the coating layer 2, which may result in low peel resistance. If the thickness of the coating layer 2 exceeds 20 μm, the film formation time tends to be longer.

[0020] The plurality of first crystals 4 include a plurality of first orientation crystals 9 which are (111) oriented and a plurality of second orientation crystals 10 which are (101) oriented or (001) oriented, and the grain size of the first orientation crystals 9 may be larger than the grain size of the second orientation crystals 10. Because the first orientation crystals 9 are dominant over the second orientation crystals 10, a coating layer forming body 101 with high peel resistance of the coating layer 2 can be easily realized by applying various other configurations of the coating layer forming body 101.

[0021] Figure 37 shows a method for identifying the first-oriented crystal 9 and the second-oriented crystal 10. For example, a crystal orientation map (inverse pole orientation map) is obtained from the photograph shown in Figure 4. The crystal 3 that appears in the (001) orientation component or the (101) orientation component extracted from this crystal orientation map may be considered the second-oriented crystal 10. The crystal 3 that appears in the (111) orientation component extracted from this crystal orientation map may be considered the first-oriented crystal 9.

[0022] More than 70% of the multiple crystals 3 may be (111) oriented. This has been confirmed to allow for the easy realization of a coating layer forming body 101 with high peel resistance of the coating layer 2 by applying various other configurations of the coating layer forming body 101.

[0023] Figure 8 is a plan view showing the results of the scratch test on test samples A, B, and C. Figure 9 is a graph showing the results of the scratch test on test samples A, B, and C. Figure 10 is a table showing the results of the scratch test on test samples A through G.

[0024] The scratch test includes chipping evaluation and substrate exposure evaluation. Chipping evaluation is an evaluation criterion for determining the critical load value Lc1 on the surface of coating layer 2 at which cracks are formed on the surface of coating layer 2. Substrate exposure evaluation is an evaluation criterion for determining the critical load value Lc2 on the surface of coating layer 2 at which the surface of substrate 1, which should be covered by coating layer 2, is exposed due to the cracks, etc.

[0025] Test samples A to G are each a coating layer forming body 101.

[0026] The definitions of terms in Figures 8 to 10 are as follows: The average critical load value (N=3) means the average value of the three critical loads obtained from three scratch tests. The (111) orientation ratio is the proportion of (111) oriented crystals 3 (first oriented crystals) among the multiple crystals 3. A (111) orientation ratio of X% or more is equivalent to X% or more of the multiple crystals 3. The average grain size of the first crystal 4 is the average grain size of the first crystal 4 in the horizontal direction relative to the substrate 1. The average grain size of the second crystal 6 is the average grain size of the second crystal 6 in the horizontal direction relative to the substrate 1. The grain size ratio of the first crystal 4 to the second crystal 6 is the ratio of the average grain size of the first crystal 4 to the average grain size of the second crystal 6.

[0027] Figures 38 and 39 show the method for calculating the average grain size. In step S1, the contour 62 of each crystal 3 is obtained, for example, by hand drawing using carbon paper. In step S2, the actual size of the coating layer 2 is used, with the area from the top to the bottom 1 μm considered as the first region 5 and the area from the bottom to the top 1 μm considered as the second region 7. For each of the first region 5 and the second region 7, a total of five horizontal lines 63 are drawn vertically at intervals of 0.25 μm. For each of these horizontal lines 63, the length of the horizontal line 63 is divided by the number of contact points between the contour 62 and the horizontal line 63 to calculate the local average grain size. The average value of the local average grain size for the five horizontal lines 63 corresponding to the first region 5 is taken as the average grain size of the first crystal 4, and the average value of the local average grain size for the five horizontal lines 63 corresponding to the second region 7 is taken as the average grain size of the second crystal 5.

[0028] The diameter of the tip of the indenter used in the scratch test was set to 0.2 mm. The minimum load applied to coating layer 2 was set to 10 N, and the maximum load was set to 60 N. For the sake of brevity, the load applied to coating layer 2 may be simply referred to as "load" below.

[0029] Figures 8 to 10 provide the following findings.

[0030] In both test specimens A and B, cracks 51 were formed under small loads, and in test specimen B, shell-shaped cracks 51 were formed. In test specimen C, the load required for crack formation was greater than that required for test specimens A and B.

[0031] (111) By increasing the orientation ratio and decreasing the crystallite size, Lc1 and Lc2 increased. From this, it can be hypothesized that increasing the orientation ratio and moderately decreasing the crystallite size are effective in improving the peel resistance of the coating layer 2.

[0032] Figure 11 is a graph showing the results of the scratch test against (111) orientation and (111) crystallite size. Figure 12 is a graph showing the results of the scratch test against (111) orientation and thickness of coating layer 2. Figure 13 is a graph showing the results of the scratch test against (111) crystallite size and thickness of coating layer 2. Figure 14 is another graph showing the results of the scratch test against (111) crystallite size and thickness of coating layer 2. Figure 15 is a graph showing the results of the scratch test against hardness of coating layer 2 and thickness of coating layer 2. Figure 16 is another graph showing the results of the scratch test against hardness of coating layer 2 and thickness of coating layer 2. Figure 13 shows the results when the (111) orientation is 80% or higher, and Figure 15 shows the results when the (111) orientation is 70% or higher. Figures 14 and 16 show the results when the (111) orientation is 50% or higher.

[0033] In each graph from Figures 11 to 16, the corresponding Lc1 or Lc2 value is shown for each point defined by the horizontal and vertical axes.

[0034] Figures 11 to 16 provide the following findings.

[0035] According to FIG. 11, as indicated by range 52, when the (111) orientation rate is 80% or more, Lc1 is large regardless of the (111) crystallite diameter. According to FIG. 12, as indicated by range 53, when the (111) orientation rate is 70% or more and the thickness of the coating layer 2 is 3.00 µm or more, Lc1 is large. According to FIG. 13, as indicated by range 54, when the (111) crystallite diameter is 400.0 Å to 550.0 Å and the thickness of the coating layer 2 is 4.00 µm or more, Lc1 is large. According to FIG. 15, as indicated by range 55, when the hardness of the coating layer 2 is 24.000 H_IT (GPa) to 26.000 H_IT (GPa) and the thickness of the coating layer 2 is 4.00 µm or more, Lc1 is large.

[0036] When the base material 1 is made of titanium, increasing the thickness of the coating layer 2 is effective for improving the peeling resistance of the coating layer 2 in order to suppress the influence of titanium, which is softer than the coating layer 2. If the coating layer 2 is simply thickened and the coating layer formed body 101 is applied to a sliding member, there is a risk that shell-like cracks 51 may be formed on the surface of the coating layer 2. Increasing the (111) orientation rate and appropriately reducing the (111) crystallite diameter can appropriately reduce the hardness of the coating layer 2, thereby suppressing the formation of shell-like cracks 51. Through these measures, the coating layer 2 which is applied on the titanium base material 1 and has high peeling resistance can be achieved. The presence of the second crystals 6 can affect the growth of the first crystals 4 above the second crystals 6.

[0037] FIG. 17 is a graph showing the results of a scratch test with respect to the thickness of the coating layer 2. FIG. 18 is a graph showing the results of a scratch test with respect to the hardness of the coating layer 2. FIG. 19 is a graph showing the results of a scratch test with respect to the (111) orientation rate. FIG. 20 is a graph showing the results of a scratch test with respect to the (111) crystallite diameter. FIG. 21 is a table showing the scratch test conditions for obtaining the results of FIGS. 17 to 20. In FIGS. 17 to 20, R ２ is the coefficient of determination.

[0038] According to FIGS. 17 to 21, the thickness of the coating layer 2, the hardness of the coating layer 2, the (111) orientation ratio, and the (111) crystallite diameter are considered to be material parameters meaningful for improving Lc1 and Lc2.

[0039] According to FIG. 17, both Lc1 and Lc2 are positive functions of the thickness of the coating layer 2. According to FIG. 18, both Lc1 and Lc2 are negative functions of the hardness of the coating layer 2. According to FIG. 19, both Lc1 and Lc2 are positive functions of the (111) orientation ratio. According to FIG. 20, both Lc1 and Lc2 are negative functions of the (111) crystallite diameter.

[0040] The method for manufacturing the coated layer formed body 101 according to Embodiment 1 of the present disclosure is as follows. A base material 1 shaped as an orthopedic implant is produced by a conventionally known method. Next, the coating layer 2 is formed on the surface of the base material 1. As a method for forming the coating layer 2, physical vapor deposition (PVD) methods such as ion plating and sputtering are applicable. To describe an example of the film forming method in detail, when the coating layer 2 is produced by ion plating, a metal target independently containing metallic titanium (Ti), metallic aluminum (Al) and metal M respectively, or a composite alloy target is used. However, M is one or more selected from the group consisting of Group 4, 5 and 6 elements of the periodic table other than Ti, Si and Y. The alloy target is disposed, for example, at opposing positions on the side wall surface of the chamber, and film formation is performed while rotating the sample. As film forming conditions, a metal source is evaporated and ionized by arc discharge, glow discharge or the like, and at the same time, nitrogen as a nitrogen source (N ２ ) gas or methane as a carbon source (CH ４ ) / acetylene (C ２ H ２ ) The coating layer 2 is formed by ion plating or sputtering that causes reaction with gas.

[0041] The AIP apparatus 64 shown in FIG. 40 includes N in a vacuum chamber 65 ２A gas such as Ar (argon) is introduced from the gas inlet 66, a cathode electrode 67 and an anode electrode 68 are arranged, and a high voltage is applied between the two electrodes to generate plasma. This plasma evaporates a desired metal or ceramic from the target and ionizes it into a high-energy state, and the ionized metal adheres to the surface of the base material 1 to form a coating layer 2 covering the surface of the base material 1. In addition, a rotating table 69 is placed inside the vacuum chamber 65. On the rotating table 69, there are arranged a sub-rotating table 70, a plurality of shaft rods 71 placed thereon, and a plurality of towers 72 each composed of a plurality of base materials 1 skewered on the shaft rods 71. Furthermore, a heater 73 for heating the base material 1, a gas outlet 74 for discharging gas out of the system, and a bias power supply 75 for applying a bias voltage to the base material 1 are arranged.

[0042] After setting the base material 1 and heating it to 550°C, an inert gas such as Ar is introduced from the gas inlet 66 before starting film formation for the purpose of cleaning the surface of the base material 1 and removing oxide films before film formation. A cathode electrode 67 and an anode electrode 68 are arranged, a high voltage is applied between the two to generate plasma, and sputter etching using inert gas is performed on the target for a certain period of time by this plasma.

[0043] Subsequently, continuous film formation is performed, so that the film is formed while the surface of the base material 1 is in an activated state. The film formation method is as follows. Using a raw material target, a metal source is evaporated and ionized by arc discharge, glow discharge or the like, and at the same time, it reacts with nitrogen (N ２ ) gas as a nitrogen source and methane (CH ４ ) / acetylene (C ２ H ２ ) gas as a carbon source to form the film. At this time, using a mixed gas of argon gas and nitrogen (N ２ ) gas in which the flow rate ratio of argon to nitrogen is 1:9 to 4:6, the coating layer 2 is formed by an ion plating method or a sputtering method. Alternatively, using a mixed gas of nitrogen (N ２A mixed gas of ) gas and argon (Ar) gas may also be used. In this case, each metal element in the target evaporates and adheres to the surface of the substrate 1, but the Ti compound evaporates in a non-uniform state, so as a result, Ti-rich columnar crystals are easily formed in the formed coating layer 2. In addition, Al and M elements, which have low vapor pressure, evaporate as large spherical lumps and adhere to the surface of the substrate 1 as so-called droplets (granular crystals). In this case, since M elements have good affinity with Ti, a lot of Ti is dissolved in the granular crystals containing a lot of M elements, so either M elements or Ti are present in large quantities, and one of them becomes the main component.

[0044] When forming the coating layer 2 by ion plating or sputtering, a specific high-hardness coating layer 2 can be formed by applying an arc current while considering the crystal structure of the coating layer 2. A bias voltage of 30V to 200V may be applied to improve adhesion with the substrate 1.

[0045] In this trial, the substrate 1 is placed in an arc ion plating apparatus equipped with a pure Ti target, and the substrate 1 is heated to a predetermined film deposition temperature. ２ The / Ar ratio, Ar bombardment time, deposition time, deposition rate, bias voltage, deposition temperature, and total pressure were set appropriately, and coating layer 2 was deposited.

[0046] Figure 22 shows the method for manufacturing a coating layer forming body 101 according to Embodiment 1 of this disclosure. ２Figure 23 is a graph showing the (111) orientation ratio with respect to Ar in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 24 is a graph showing the (111) orientation ratio with respect to film formation time in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 25 is a graph showing the (111) orientation ratio with respect to film formation rate in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 26 is a graph showing the (111) orientation ratio with respect to bias voltage in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 27 is a graph showing the (111) orientation ratio with respect to film formation temperature in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 28 is a graph showing the (111) orientation ratio with respect to total pressure in the manufacturing method of the coating layer forming body 101 according to Embodiment 1 of this disclosure. Figure 29 is a table showing the manufacturing conditions for the coating layer forming body 101 according to Embodiment 1 of this disclosure, for obtaining the results shown in Figures 22 to 28.

[0047] According to Figure 22, as shown in range 56, N ２ When / Ar is (1 / 7) or greater, N ２The (111) orientation ratio is significantly higher when / Ar is (1 / 10) or less compared to when it is (1 / 10) or less. As shown in Figure 23, as indicated in range 57, the (111) orientation ratio is significantly higher when the Ar bombardment time is 2 min compared to when the Ar bombardment time is 8 min or more. As shown in Figure 24, as indicated in range 58, the (111) orientation ratio is significantly higher when the deposition time is 100 min or more compared to when the deposition time is less than 100 min. As shown in Figure 25, as indicated in range 59, the (111) orientation ratio is significantly higher when the deposition rate is 0.04 μm / min or less compared to when the deposition rate is 0.05 μm / min or more. As shown in Figure 26, as indicated in range 60, the (111) orientation ratio is significantly higher when the bias voltage is 65 V compared to when the bias voltage is other than 65 V. As shown in Figure 27, in range 61, the (111) orientation ratio is significantly larger when the deposition temperature is 500°C or higher compared to when the deposition temperature is 300°C. As shown in Figure 28, no significant change in the (111) orientation ratio is observed with respect to changes in total pressure.

[0048] From the above, (111) In order to increase the orientation ratio, N ２ It is considered effective to control at least one of the following: / Ar, Ar bombardment time, deposition time, deposition rate, bias voltage, and deposition temperature.

[0049] [Embodiment 2] Figure 30 is a cross-sectional view showing the configuration of the coating layer forming body 101 according to Embodiment 2 of the present disclosure.

[0050] Figure 31 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, observed by SEM. Figure 32 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, observed by TEM. Figure 33 is a first example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, analyzed by EBSD.

[0051] Figure 34 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, observed by SEM. Figure 35 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, observed by TEM. Figure 36 is a second example of a cross-sectional photograph of the coating layer forming body 101 according to Embodiment 2 of this disclosure, analyzed by EBSD.

[0052] Figures 31 to 36 show the third crystal 8 and its surroundings within the coating layer-forming body 101.

[0053] The plurality of crystals 3 include a plurality of third crystals 8 in contact with the substrate 1, and the grain size of the third crystals 8 may be larger than the grain size of the second crystals 6. The grain size of the third crystals 8 being larger than the grain size of the second crystals 6 may be interpreted as the largest grain size among the plurality of third crystals 8 being larger than the largest grain size among the plurality of second crystals 6. The grain size of the third crystals 8 being larger than the grain size of the second crystals 6 may be interpreted as the smallest grain size among the plurality of third crystals 8 being larger than the smallest grain size among the plurality of second crystals 6.

[0054] The configuration of the coating layer forming body 101 according to Embodiment 2 of this disclosure may be optionally applied to the coating layer forming body 101 according to Embodiment 1 of this disclosure. The coating layer forming body 101 according to Embodiment 1 of this disclosure may further include the configuration of the coating layer forming body 101 according to Embodiment 2 of this disclosure.

[0055] The thickness of the coating layer 2 may be 3 μm or more and 20 μm or less. If the thickness of the coating layer 2 is less than 3 μm, even if various other configurations of the coating layer forming body 101 are applied, the coating layer 2 may be too thin and have low peel resistance. Specifically, if the coating layer 2 is too thin, the Young's modulus of the substrate 1 is lower than that of the coating layer 2, causing the substrate 1 to deform during sliding, and tensile stress to act inside the coating layer 2, which may result in low peel resistance. If the thickness of the coating layer 2 exceeds 20 μm, the film formation time tends to be longer.

[0056] [Summary] A coating layer forming body according to embodiment 1 of the present disclosure comprises a substrate and a coating layer located above the substrate, wherein the coating layer has a plurality of crystals containing Ti and N, a first region including a plurality of first crystals belonging to the plurality of crystals, and a second region located closer to the substrate than the first region and including a plurality of second crystals belonging to the plurality of crystals, wherein the grain size of the second crystals is smaller than the grain size of the first crystals.

[0057] In the coating layer forming body according to embodiment 2 of the present disclosure, in embodiment 1, the average grain size of the plurality of second crystals is smaller than the average grain size of the plurality of first crystals.

[0058] In the coating layer forming body according to embodiment 3 of the present disclosure, in embodiment 1 or 2, the average crystal grain size in the horizontal direction with respect to the substrate in the plurality of second crystals is 0.14 μm or less.

[0059] In the coating layer forming body according to embodiment 4 of the present disclosure, in any of embodiments 1 to 3, the average crystal grain size in the horizontal direction with respect to the substrate in the plurality of first crystals is 0.14 μm or more.

[0060] In the coating layer forming body according to embodiment 5 of the present disclosure, in any of embodiments 1 to 4, the ratio obtained by dividing the average grain size in the horizontal direction with respect to the substrate in the plurality of first crystals by the average grain size in the horizontal direction with respect to the substrate in the plurality of second crystals is 1.4 or more.

[0061] In the coating layer forming body according to embodiment 6 of the present disclosure, in any of embodiments 1 to 5, the thickness of the coating layer is 3 μm or more and 20 μm or less.

[0062] In any of embodiments 1 to 6, the coating layer forming body according to embodiment 7 of the present disclosure comprises a plurality of first oriented crystals having a (111) orientation and a plurality of second oriented crystals having a (101) orientation or a (001) orientation, wherein the grain size of the first oriented crystals is larger than the grain size of the second oriented crystals.

[0063] In the coating layer forming body according to embodiment 8 of the present disclosure, in any of embodiments 1 to 7, 70% or more of the plurality of crystals are (111) oriented.

[0064] In the coating layer forming body according to embodiment 9 of the present disclosure, in any of embodiments 1 to 8, the plurality of crystals include a plurality of third crystals in contact with the substrate, and the grain size of the third crystals is larger than the grain size of the second crystals.

[0065] In the coating layer forming body according to embodiment 10 of the present disclosure, in embodiment 9, the thickness of the coating layer is 3 μm or more and 20 μm or less.

[0066] The inventions described in this disclosure have been explained above based on the drawings and embodiments. However, the inventions described in this disclosure are not limited to the embodiments described above. That is, the inventions described in this disclosure can be modified in various ways within the scope shown in this disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the inventions described in this disclosure. In other words, it should be noted that it is easy for those skilled in the art to make various modifications or alterations based on this disclosure. Furthermore, it should be noted that these modifications or alterations are included in the scope of this disclosure.

[0067] 1 Substrate 2 Coating layer 3 Crystal 4 First crystal 5 First region 6 Second crystal 7 Second region 8 Third crystal 101 Coating layer forming body

Claims

1. A coating layer forming body comprising a substrate and a coating layer located above the substrate, wherein the coating layer has a plurality of crystals containing Ti and N, a first region containing a plurality of first crystals belonging to the plurality of crystals, and a second region located closer to the substrate than the first region and containing a plurality of second crystals belonging to the plurality of crystals, wherein the grain size of the second crystals is smaller than the grain size of the first crystals.

2. The coating layer forming body according to claim 1, wherein the average grain size of the plurality of second crystals is smaller than the average grain size of the plurality of first crystals.

3. The coating layer forming body according to claim 1 or 2, wherein the average grain size of the plurality of second crystals is 0.14 μm or less.

4. The coating layer forming body according to any one of claims 1 to 3, wherein the average grain size of the plurality of first crystals is 0.14 μm or more.

5. The coating layer forming body according to any one of claims 1 to 4, wherein the ratio obtained by dividing the average grain size of the plurality of first crystals by the average grain size of the plurality of second crystals is 1.4 or more.

6. The coating layer forming body according to any one of claims 1 to 5, wherein the thickness of the coating layer is 3 μm or more and 20 μm or less.

7. The coating layer forming body according to any one of claims 1 to 6, wherein the plurality of first crystals comprises a plurality of first oriented crystals having a (111) orientation and a plurality of second oriented crystals having a (101) orientation or a (001) orientation, and the grain size of the first oriented crystals is greater than the grain size of the second oriented crystals.

8. The coating layer forming body according to any one of claims 1 to 7, wherein 70% or more of the plurality of crystals are (111) oriented.

9. The coating layer forming body according to any one of claims 1 to 8, wherein the plurality of crystals includes a plurality of third crystals in contact with the substrate, and the grain size of the third crystals is larger than the grain size of the second crystals.

10. The coating layer forming body according to claim 9, wherein the thickness of the coating layer is 3 μm or more and 20 μm or less.

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