Two-phase TiAlSiBN coating for cutting

Abstract

The present invention relates to a TiAlBSiN coating deposited on the surface of a substrate (1), wherein the coating (100) comprises three different coating portions along its coating thickness: a first portion (5), a second portion (10), and a third portion (50), the first portion (5) being deposited closer to the surface of the substrate (1) than the second and third portions, the second portion (10) being deposited directly on the outermost surface of the first portion (5), and the third portion (50) being deposited directly on the outermost surface of the second portion (10). The first portion (5) is formed from one or more layers, in either case formed by at least one adhesive layer, the first portion (5) exhibits either a completely cubic crystalline phase or a mixture of crystalline phases including a cubic crystalline phase and a hexagonal wurtzite phase of the crystal, and if it is a mixture of crystalline phases, it mainly exhibits a cubic phase, and at least one adhesive layer contains titanium and nitrogen; and The second portion (10) is formed from one or more layers, in either case formed by at least one support layer, the second portion (10) shows either a completely crystalline hexagonal wurtzite phase or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, and in the case of a mixture of crystalline phases, it shows mainly a wurtzite phase, and the at least one support layer contains titanium, aluminum, nitrogen, and at least one chemical element selected from boron and silicon; and The third portion (50) is formed from one or more layers, in either case being formed from at least one functional layer, the third portion (50) exhibiting either a completely crystalline cubic phase or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, the mixture of crystalline phases exhibiting primarily a cubic phase, and at least one functional layer containing titanium, silicon, and nitrogen.

Description

[Technical Field]

[0001] This application relates to a novel TiAlSiBN coating with improved performance, which is particularly advantageous for tools used in cutting processes, and is therefore especially suitable for cutting applications. [Background technology]

[0002] This application claims priority to German Patent Application No. 10 2023 002 527.5, filed on 21 June 2023, the entire contents of which are expressly incorporated herein by reference.

[0003] TiAlN and / or TiSiN layer (for example, Ti 1-x Al x N / Ti y Si 1-y Coating systems, including N-coating systems, are widely known as hard machining coating systems because they exhibit excellent protective performance against harsh cutting conditions, such as high thermal loads, oxidation, and wear.

[0004] In particular, the use of coating systems including a TiAlN layer as a support layer and a TiSiN layer as a top layer has been successful mainly for the following reasons: i. High thermal stability of the TiSiN top layer, as well as oxidation resistance and wear resistance. ii. The TiAlN support layer provides high hardness and toughness, while simultaneously offering good adhesion to the substrate. [Overview of the Initiative]

[0005] However, even in such coating systems, it was observed that the TiAlN support layer has a rougher morphology compared to the TiSiN top layer, which can lead to cohesive failure.

[0006] Furthermore, when the temperature rises during machining and the coating system is exposed to the resulting high temperatures, it has been observed that the thermodynamically metastable cubic TiAlN decomposes into cubic TiN and wurtzite AlN. This phase transition is undesirable because it can cause an undesirable decrease in hardness and elastic modulus, and a volume change of up to 20% per mole. This was also confirmed in the cutting tests reported by Horling et al. in the academic paper "Mechanical Properties and Machining Performance of Ti 1-x Al x N Coated Cutting Tools" (Surface and Coatings Technology, Vol. 191, Nos. 2-3, February 21, 2005, pp. 384-392).

[0007] The inventors intended to reduce the adverse effects of the aforementioned phase decomposition by using a two-phase TiAlN layer (a TiAlN layer showing both cubic and wurtzite phases, preferably mainly showing the wurtzite phase) instead of a fully cubic TiAlN layer (a TiAlN layer showing only the cubic phase).

[0008] However, the two-phase TiAlN layer showed undesirable mechanical properties (especially when using typical cutting tool substrates formed from hard materials such as cemented carbide, cubic boron nitride (cBN), and cermet), and had poor adhesion to the substrate.

[0009] Problems to be Solved Decomposition of the Ti 1-x Al x N / Ti y Si 1-y N coating system's Ti 1-x Al x N bottom layer causes cracks in the Ti 1-x Al x N bottom layer, and as a result, causes damage to the Ti 1-x Al x N / Ti y Si 1-y N coating system. ​​​1-x Al x N bottom layer is Ti y Si 1-y Because it has a coarser morphology compared to the N top layer, Ti 1-x Al x N bottom layer and Ti y Si 1-y Cohesive failure occurs at the interface of the N-top layer.

[0011] Objective of the present invention The main objective of the present invention is to provide a novel coating that exhibits superior performance compared to known coatings containing TiAlN and / or TiSiN layers, particularly in cutting applications. It is especially effective when using cutting tool substrates made from hard materials such as cemented carbide, cubic boron nitride (cBN), and cermet.

[0012] A further object of the present invention is to alleviate the above-mentioned problems observed in a coating system including a TiAlN support layer and a TiSiN top layer without causing deterioration of the mechanical properties of the coating system or its adhesion to the substrate.

[0013] Solution according to the present invention The above objective is achieved by the present invention by providing a novel two-phase TiAlSiBN coating according to claim 1.

[0014] The TiAlSiBN coating of the present invention (see schematic diagram of coating 100 in Figure 1 - in this specification, the TiAlSiBN coating of the invention is also called a novel two-phase TiAlSiBN coating or simply a two-phase TiAlSiBN coating) is a coating comprising at least three layers, the first of the at least three layers being a first layer (see coating portion 5 in Figure 1) that mainly exhibits a crystalline cubic phase and contains Ti and N and functions as an adhesion layer, the second of the at least three layers being a second layer (see coating portion 10 in Figure 1) that functions as a support layer and mainly exhibits a crystalline hexagonal wurtzite phase and contains Ti, Al, N, and additionally B and / or Si, and the third of the at least three layers being a third layer (see coating portion 50 in Figure 1) that functions as a functional layer and mainly exhibits a crystalline cubic phase and contains Ti, Si and N.

[0015] The crystalline hexagonal wurtzite phase in the TiAlSiBN coating 100 contains Al and N.

[0016] The term "functions as an adhesive layer" specifically refers to improving the adhesion between the TiAlSiBN coating 100 and the substrate surface on which the TiAlSiBN coating 100 is deposited. The first portion 5 comprises one or more adhesive layers and is deposited as close as possible to the surface of the substrate 1, preferably directly on the substrate surface.

[0017] The term "functions as a support layer" specifically refers to improving the cohesive forces and mechanical properties within the TiAlSiBN coating 100, thereby supporting the functional layer deposited thereon. The second portion 10 may include one or more support layers, which are deposited as close as possible to the first portion 5, preferably directly on the outermost surface of the first portion 5.

[0018] In this specification, the functional layer may also be referred to as the top layer, and the third portion 50 may be formed from one or more top layers. Preferably, the outermost layer of the third portion 50 in the TiAlSiBN coating 100 is the outermost surface of the coated substrate surface.

[0019] Between the substrate surface and the first portion 5 of the TiAlSiBN coating 100, one or more layers of metal layers or metal nitride layers (not shown in Figure 1) are optionally provided to modify the properties of the substrate surface before the formation of the TiAlSiBN coating 100 begins.

[0020] The upper part of the third portion 50 of the TiAlSiBN coating 100 may optionally be provided with one or more decorative or smoothing layers, for example (not shown in Figure 1). These are used to modify the outermost surface of the TiAlSiBN coating 100.

[0021] In any case, the sum of the thicknesses of any of the above-mentioned layers is preferably less than or equal to the sum of the thicknesses of the first portion 5, the second portion 10, and the third portion 50 forming the TiAlSiBN coating 100, more preferably less than or equal to 50% of the sum of the thicknesses of the first portion 5, the second portion 10, and the third portion 50, and even more preferably less than or equal to 30% of the sum of the thicknesses of the first portion 5, the second portion 10, and the third portion 50.

[0022] In a preferred embodiment, the novel two-phase TiAlSiBN coating according to the present invention comprises three distinct portions along the thickness of the coating, each portion comprising at least one layer. Thus, the two-phase TiAlSiBN coating of the present invention comprises at least three layers, namely, at least one adhesive layer comprising the first portion 5, at least one support layer comprising the second portion 10 (the support layer is also referred to herein as the bottom layer), and at least one functional layer comprising the third portion 50 (the functional layer is also referred to herein as the top layer).

[0023] The first part is provided to improve the adhesion of the TiAlSiBN coating to the substrate surface.

[0024] The second section is provided to improve cohesiveness within the TiAlSiBN coating, while simultaneously offering high hardness and toughness, and ensuring good support for the third section.

[0025] The third section is provided to achieve high thermal stability, as well as oxidation resistance and wear resistance.

[0026] The first part is formed by at least one adhesive layer (e.g., one or more adhesive layers), the second part is formed by at least one support layer (e.g., one or more support layers), and the third part is formed by at least one top layer (e.g., one or more top layers). Here: At least one adhesive layer, preferably the entire first portion: This refers to a material exhibiting a completely crystalline cubic phase (hereinafter abbreviated as "cub"), particularly a face-centered cubic phase (usually abbreviated as fcc phase), or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase (hereinafter abbreviated as "hex" or "wur"), where, in the case of a mixture of crystalline phases, it mainly exhibits a cubic phase and is detectable, for example, by transmission electron microscopy (TEM) (see, for example, Figure 3), and It contains titanium (Ti) and nitrogen (N), and optionally further contains at least one of aluminum (Al), boron (B), and silicon (Si), preferably aluminum (Al) and boron (B); At least one bottom layer, preferably the entire second portion: This represents either a completely crystalline hexagonal wurtzite phase or a mixture of crystalline phases containing a crystalline cubic phase and a crystalline hexagonal wurtzite phase, where, in the case of a mixture of crystalline phases, it mainly represents the wurtzite phase, which can be detected, for example, by transmission electron microscopy (TEM) (see, for example, Figure 3), and It comprises titanium (Ti), aluminum (Al), and nitrogen (N), and additionally comprises at least one of boron (B) and silicon (Si), preferably boron (B); At least one top layer, preferably the entire third portion: This refers to a completely crystalline cubic phase, particularly the fcc phase, or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, where, in the case of a mixture of crystalline phases, it mainly exhibits a cubic phase and is detectable, for example, by transmission electron microscopy (TEM) (not shown in Figure 3), and Containing titanium (Ti), silicon (Si), and nitrogen (N); When each coating portion 5, 10, and 50 (i.e., at least one adhesive layer, at least one bottom layer, and at least one top layer) was separately deposited on the substrate surface and analyzed using X-ray diffraction (XRD) analysis, the ratio of the cubic phase to the wurtzite phase was: In the adhesive layer, it is preferably greater than 0.3, and therefore cub / wur≧0.3, and in the bottom layer, it is preferably in the range of 0.01 to 0.3, and therefore 0.01 <cub / wur<0.3であり、 Preferably, the top layer is greater than 1, i.e., cub / wur > 1, and more preferably, at least one of the top layers may exhibit a completely crystalline cubic phase.

[0027] The aforementioned ratio of the cubic phase to the wurtzite phase corresponds to the peak intensity ratio of (200) cubic phase / (110) wurtzite phase.

[0028] In this specification, the term "peak intensity" is used, in particular, to refer to the net height of the corresponding peak (measured using the known X-ray diffraction analysis software EVA).

[0029] The measurements performed to define the above numerical range for the ratio of the cubic phase to the wurtzite phase were obtained using XRD techniques. In these measurements, the cubic phase peak (200) is located at a 2-theta angle of 40–44°, and the wurtzite phase peak (110) is located at a 2-theta angle of 49–60°. X-ray diffraction (also abbreviated as XRD) was performed using a Bruker X-ray diffractometer with a theta-2-theta configuration and a copper X-ray tube with a wavelength of 1.5406 angstroms (see, for example, Figure 4).

[0030] Similarly, when each coating portion 5, 10, and 50 (i.e., at least one adhesive layer, at least one bottom layer, and at least one top layer) is individually deposited on the substrate surface and analyzed using a known nanoindentation technique, the elastic modulus (Young's modulus, hereafter abbreviated as E) is: The adhesive layer may preferably be in the range of 300 GPa to 480 GPa, and more precisely, 300 ± 15 GPa ≤ E < 480 ± 15 GPa. The bottom layer may preferably be in the range of 250 GPa to 360 GPa, and more precisely, 250 ± 15 GPa ≤ E < 360 ± 15 GPa. Preferably, the E of the adhesive layer is higher than the E of the bottom layer.

[0031] Preferably, the bottom layer exhibits a mainly wurtzite phase characterized by an XRD peak intensity ratio of (200) cubic / (110) wurtzite in the range of 0.01 to less than 0.3, and a Young's modulus E between 250 GPa and 360 GPa (when the measurement error is plus or minus 15 GPa), where the cubic peak (200) is located at a 2-theta angle of 40 to 44°, and the wurtzite peak (110) is located at a 2-theta angle of 49 to 60°.

[0032] Preferably, the adhesive layer exhibits a mainly cubic phase characterized by an XRD peak intensity ratio of (200) cubic / (110) wurtzite of 0.3 or more and a Young's modulus E of 300 GPa to 450 GPa (when the measurement error is plus or minus 15 GPa), with the cubic peak (200) located at a 2-theta angle of 40 to 44° and the wurtzite peak (110) located at a 2-theta angle of 49 to 60°.

[0033] The aforementioned numerical ranges for hardness and elastic modulus were defined based on measurements using standard nanoindentation techniques, which are typically used for PVD coating films within the thickness ranges described herein.

[0034] Figure 5 shows the change in elastic modulus measured in a sample in which a substrate 1 is coated with the TiAlSiBN coating 100 according to the present invention. This coating 100 includes an adhesive layer forming the first portion 5, a support layer forming the second portion 10, and a functional layer as a top layer (and as the outermost layer of the TiAlSiBN coating 100) forming the third portion 50.

[0035] The common nanoindentation techniques and parameters listed in Table 1 were used to measure the modulus of elasticity:

[0036] [Table 1]

[0037] Before measuring the elastic modulus, the surface of the coated sample was treated with a known carrot polishing process to expose each layer for elastic modulus measurement.

[0038] According to a further preferred embodiment of the present invention, the elemental composition at atomic concentration of at least one adhesive layer, preferably the entire first portion, is given by the following formula: (Ti x Al y B z Si w ) t N u Here: x+y+z+w=1, and 0 ≤ y / x ≤ 0.21 or y / (x+y) < 0.67, and 0 ≤ z + w ≤ 0.25, preferably 0 ≤ z + w ≤ 0.10, more preferably 0 <z+w≦0.05、かつ 0≦z≦0.10, preferably 0≦z≦0.05, more preferably 0.01≦z<0.05, and 0≦w≦0.25, preferably 0≦w≦0.10, and 0.75 ≤ t / u ≤ 1.25, preferably 0.85 ≤ t / u ≤ 1.15

[0039] According to a further preferred embodiment of the present invention, the elemental composition at atomic concentration of at least one bottom layer, preferably the entire second portion, is given by the following formula: (Ti a Al b B c Si d ) v N q Here: a+b+c+d=1, and 0≦b / a≦2.1 and / or 0≦b / (a+b)<0.67, preferably 1≦b / a≦2.1, and 0 ≤ c + d ≤ 0.25, preferably 0 ≤ c + d ≤ 0.10, more preferably 0 <c+d≦0.05、かつ 0≦c≦0.05, preferably 0.01≦c<0.05, more preferably 0.01≦c≦0.04, and 0≦d≦0.25, preferably 0≦d≦0.10, and 0.75 ≤ v / q ≤ 1.25, preferably 0.85 ≤ v / u ≤ 1.15

[0040] According to a further preferred embodiment of the present invention, the elemental composition in atomic concentration of at least one top layer, preferably the entire third portion, is given by the following formula: (Ti e Si f ) g N h Here: e+f=1, and 0.5 ≤ f ≤ 0.35, preferably 0.5 ≤ f ≤ 0.25, and 0.75 ≤ r / p ≤ 1.25, preferably 0.85 ≤ r / p ≤ 1.15

[0041] To describe the present invention in more detail, refer to the drawings (Figures 1 to 4), examples, and results below. However, it should be understood that this information is intended to illustrate preferred embodiments and examples of the present invention and is not intended to limit the invention. [Brief explanation of the drawing]

[0042] Figure caption: [Figure 1] Figure 1: Schematic diagram of the two-phase TiAlSiBN coating according to the present invention [Figure 2] Figure 2: Comparison of wear changes and cutting conditions between a variant of the prior art and a variant of the invention. [Figure 3] Figure 3: TEM selective region diffraction pattern confirming a fitted TiAlBN adhesive layer in one preferred variant of the coating according to the invention. [Figure 4] Figure 4: XRD comparison of conventional coating and the inventive coating [Figure 5] Figure 5: Change in elastic modulus along the thickness of the TiAlSiBN coating 100 according to the invention. [Modes for carrying out the invention]

[0043] Figure 1 schematically shows a coated product 200 coated with a preferred embodiment of the two-phase TiAlSiBN coating 100 according to the present invention. Here, the first portion 5 of the TiAlSiBN coating 100 (for example, with a chemical elemental composition (Ti x Al y B z Si w ) t N u The second portion 10 (for example, with a chemical elemental composition (Al)) is formed by or includes one adhesive layer having the same, and the second portion 10 (for example, with a chemical elemental composition (Al)) is formed by directly depositing the adhesive layer on the surface of the substrate 1, and the second portion 10 (for example, with a chemical elemental composition (Al)) a Ti b Si c B d ) e N q A bottom layer having or including the above is formed directly on the first portion 5, and the third portion 50 (for example, with a chemical elemental composition (Ti e Si f ) g N h A top layer having (or including) is formed directly onto the second portion 10.

[0044] According to yet another preferred embodiment of the present invention, at least one adhesive layer within the first part 5, preferably the entire part 5 (i.e., all adhesive layers within part 5), has a chemical elemental composition in atomic percentages (without considering contaminating elements, i.e., unavoidable impurities which should be less than 2 atomic percent of the total of all elements present), and the formula is (Al af Ti bf B qf ) cf N df The values ​​are expressed as af+bf+qf=1, 0.75≦cf / df≦1.15, 0.425≦af≦0.76, 0.17≦bf≦0.425, 0.002≦qf≦0.05, preferably 0.003≦qf≦0.050, more preferably 0.003≦qf≦0.045 or 0.003≦qf≦0.040, and are measured using standard ToF-ERDA (Time-of-Flight Elastic Recoil Detection Analysis) or ERDA (Elastic Recoil Detection Analysis) and SIMS (Secondary Ion Mass Spectrometry) techniques, which are standardly used for PVD coating films having the thickness range described herein and containing the elements described herein.

[0045] According to yet another preferred embodiment of the present invention, at least one adhesive layer within the first part 5, preferably the entire first part 5 (i.e., all adhesive layers within part 5), has a chemical elemental composition in atomic percentages (without considering contaminating elements, i.e., unavoidable impurities which should be less than 2 atomic percent of the total of all elements present), and is of formula (Al ai Ti bi B qi ) ci N di It is expressed as ai + bi + qi = 1, 0.75 ≤ ci / di ≤ 1.15, 0.425 ≤ ai ≤ 0.76, 0.17 ≤ bi ≤ 0.425, 0.002 ≤ qi ≤ 0.05, preferably 0.003 ≤ qi ≤ 0.050, more preferably 0.003 ≤ qi ≤ 0.045 or 0.003 ≤ qi ≤ 0.040, which is measured using ERDA and SIMS techniques.

[0046] More preferably (as with the first part 5 of the embodiment described immediately above), at least one bottom layer in the second part 10, preferably the entire second part 10 (i.e., all bottom layers in part 10), has a chemical elemental composition in atomic percentages (without considering contaminating elements, i.e., unavoidable impurities which should be less than 2 atomic percent of the total of all elements present), and is of formula (Al ai Ti bi B qi )ciN di It is expressed as ai + bi + qi = 1, 0.75 ≤ ci / di ≤ 1.15, 0.425 ≤ ai ≤ 0.76, 0.17 ≤ bi ≤ 0.425, 0.002 ≤ qi ≤ 0.05, preferably 0.003 ≤ qi ≤ 0.050, more preferably 0.003 ≤ qi ≤ 0.045 or 0.003 ≤ qi ≤ 0.040, which is measured using ERDA and SIMS techniques.

[0047] In this specification, and particularly in the context described later, the following terms are used to facilitate the description and explanation of embodiments: The term "adhesive layer" is used when referring to the entire first part 5 of the TiAlSiBN coating 100. The term "bottom layer" is used when referring to the entire second portion 10 of the TiAlSiBN coating 100. The term "top layer" is used to refer to the entire third portion 50 of the TiAlSiBN coating 100.

[0048] Chemical elemental composition of the adhesive layer (atomic percentage) (Comp Bottom_1stPort ) and the chemical elemental composition (atomic percentage) of the bottom layer (Comp Bottom_lastPort ) being similar or equal is, i.e., 0.9 ≤ Comp Bottom_1stPort / Comp Bottom_lastPort It is ≤ 1.11.

[0049] Preferably, taking into account the values ​​at the lower 10f of the bottom layer 10, the chemical element composition along the thickness of the bottom layer is constant or varies by a rate of less than 10%, more preferably less than 5%.

[0050] According to yet another preferred embodiment of the present invention, the top layer has a chemical elemental composition in atomic percentages (without considering contaminating elements, i.e., unavoidable impurities which should be less than 2 atomic percent of the total of all elements present), and the formula (Ti e Si f ) g N h It is expressed as follows, where e+f=1, 0.75≦g / h≦1.15, 0.6≦e≦0.95, and 0.05≦f≦0.4.

[0051] According to a further preferred embodiment of the present invention, an adhesive layer 5 (see Figures 3 and 4) is formed between the bottom layer 10 and the surface of the substrate 1 to be coated (hereinafter also referred to as the coated substrate surface or simply the substrate surface) having a two-phase TiAlBSiN coating. Here, the adhesive layer 5 mainly exhibits a face-centered cubic phase. When the bottom layer is a TiAlBN layer, the adhesive layer 5 is preferably a TiAlN layer or a TiAlBN layer.

[0052] The surface of the coating system preferably exhibits an average roughness Ra of less than 0.05 μm.

[0053] The coating exhibits excellent wear resistance, particularly in machining, when applied to cutting tools.

[0054] By doping the bottom layer of TiAlN with boron (B), a two-phase structure (of TiAlBN) is formed, which improves the mechanical properties and yields a feathery, fine morphology similar to that of TiSiN. [Examples]

[0055] To demonstrate the significant improvements achieved by using the coating according to the present invention in cutting applications, three inventive examples and two non-inventive examples are described in detail below: All coatings in the examples were deposited using high-power pulsed magnetron sputtering (HiPIMS) technology. However, the use of this method should not be construed as limiting the methods available for producing the coatings of the present invention. Any physical vapor deposition (PVD) technique can be used to produce the original coatings according to the present invention.

[0056] Deposition of film T1 (non-inventive example): The T1 coating consists of a TiAlN bottom layer and a TiSiN top layer. Both TiAlN and TiSiN exhibit a face-centered cubic phase.

[0057] The TiAlN bottom layer was deposited using a known method with a TiAl target having an atomic percentage ratio of Ti to Al of Ti / Al = 40 / 60. The TiAl target was sputtered (via HiPIMS) in a reactive atmosphere containing argon as the inert gas and nitrogen as the reactive gas. A negative bias voltage of -50V was applied to the substrate during the deposition of the TiAlN bottom layer.

[0058] The TiAlN bottom layer was deposited directly onto the substrate.

[0059] The TiSiN top layer was deposited on the TiAlN bottom layer using a TiSi target with an atomic percentage ratio of Ti to Al of Ti / Si = 75 / 25, by a known method. The TiSi target was sputtered (via HiPIMS) in a reactive atmosphere containing argon as the inert gas and nitrogen as the reactive gas. A negative bias voltage of -70V was applied to the substrate during the deposition of the TiSiN top layer.

[0060] Deposition of T2 film (example of invention): The T2 coating consists of a TiAlBN adhesive layer, a TiAlBN bottom layer, and a TiSiN top layer. The TiAlBN adhesive layer exhibits a face-centered cubic phase, the TiAlBN bottom layer exhibits a hexagonal wurtzite phase, and the TiSiN top layer exhibits a face-centered cubic phase.

[0061] The TiAlBN adhesive layer and bottom layer were deposited using a TiAlB target with Ti, Al, and B content in atomic percentages of Ti=32, Al=63, and B=5. The TiAlB target was sputtered (via HiPIMS) in a reactive atmosphere containing argon as the inert gas and nitrogen as the reactive gas. A negative bias voltage of -100V was applied to the substrate during the deposition of the TiAlBN bottom layer. The difference in deposition between the cubic phase TiAlBN adhesive layer and the wurtz phase bottom layer was achieved by setting different total pressures during the deposition of the TiAlBN adhesive layer and bottom layer. The total pressure used during the deposition of the TiAlBN adhesive layer (in the range of 0.1 Pa to 0.5 Pa) was lower than the total pressure used during the deposition of the TiAlBN bottom layer (in the range of greater than 0.5 Pa to 0.9 Pa).

[0062] The TiAlBN adhesive layer was deposited directly onto the substrate.

[0063] The TiSiN top layer was deposited in the same manner as the TiSiN top layer of Example T1, the only difference being that the negative bias voltage applied to the substrate during the deposition of the TiSiN top layer was -50V.

[0064] T3 film deposition (example of invention): The T3 coating consists of a TiAlBN adhesive layer, a TiAlBN bottom layer, and a TiSiN top layer. The TiAlBN adhesive layer exhibits a face-centered cubic phase, the TiAlBN bottom layer exhibits a hexagonal wurtzite phase, and the TiSiN top layer exhibits a face-centered cubic phase.

[0065] The TiAlBN adhesive layer and TiAlBN bottom layer were deposited using a TiAlB target having atomic percentages of Ti=32, Al=63, and B=5. The TiAlB target was sputtered (via HiPIMS) in a reactive atmosphere containing argon as the inert gas and nitrogen as the reactive gas. The phase difference between the TiAlBN adhesive layer and the TiAlBN bottom layer was achieved by setting different pressures and bias voltages during the deposition of the TiAlBN bottom layer. Similar to T2, the total pressure used during the deposition of the adhesive layer was set lower than the total pressure used during the deposition of the bottom layer. In T3, the negative bias voltage applied to the substrate during the deposition of the adhesive layer was -50V, and during the deposition of the bottom layer it was -100V.

[0066] The TiAlBN adhesive layer was deposited directly onto the substrate.

[0067] The TiSiN top layer was deposited using the exact same method as the TiSiN top layer in Example T2.

[0068] T4 film deposition (example of invention): The T4 coating consists of a TiAlBN bottom layer, a TiSiN top layer, and a TiAlN adhesive layer. The TiAlBN bottom layer exhibits a hexagonal wurtzite phase. The TiSiN top layer and TiAlN adhesive layer exhibit a face-centered cubic phase.

[0069] The TiAlBN bottom layer was deposited using a TiAlB target with atomic percentages of Ti=32, Al=63, and B=5. The TiAlB target was sputtered (via HiPIMS) in a reactive atmosphere containing argon as the inert gas and nitrogen as the reactive gas. No distinct regions were formed in the TiAlBN bottom layer. A negative bias voltage of -100V was applied to the substrate during the deposition of the TiAlBN bottom layer.

[0070] The TiAlBN bottom layer was not deposited directly onto the substrate; instead, an adhesive layer of TiAlN exhibiting a face-centered cubic phase was deposited between the substrate and the TiAlBN bottom layer. The coating of the adhesive layer was carried out by a known method under the same conditions as those described for the TiAlN bottom layer in Example T1.

[0071] The TiSiN top layer was deposited using the exact same method as the TiSiN top layer in Examples T2 and T3.

[0072] T5 film deposition (non-inventive example): The only difference between T4 and T5 is that T5 does not include an adhesive layer, and the TiAlBN bottom layer exhibiting a hexagonal wurtzite phase is deposited directly onto the substrate. Otherwise, the deposition of T5 was carried out in the same way as T4.

[0073] Generally, the inventive coating according to the present invention includes at least one adhesive layer exhibiting a face-centered cubic phase, a bottom layer of TiAlBN, TiAlBSiN, or TiAlSiN exhibiting a hexagonal wurtzite phase, a top layer of TiSiN exhibiting a face-centered cubic phase, and an adhesive layer of TiN, TiAlN, TiAlBN, TiAlBSiN, or TiAlSiN exhibiting a face-centered cubic phase.

[0074] The inventors found that by using the coated tools according to the present invention, tool life can be extended by more than 50% compared to conventional coatings, and the coated tools were tested in milling hard materials.

[0075] Further detailed investigations and tests were conducted on the coating described in the above examples. Figures 2 to 4 are used to illustrate the invention in more detail, but they do not limit the invention.

[0076] Figure 2 shows a comparison of wear changes between a non-inventive coating (e.g., a two-layer coating of TiAlN and TiSiN) and an inventive coating (e.g., a variant of the invention including an AlTiBN layer and a TiSiN layer), and the respective cutting conditions. The corresponding tool (in this case, a WC-C ball nose end mill) was used for machining hardened steel after being coated with the non-inventive and inventive coatings (T1-T5) as described above. T5 shows that using an AlTiBN bottom layer and a TiSiN top layer without at least a primarily (i.e., mostly) cubic (suitable) adhesive layer (e.g., an adhesive layer of cubic TiAlN) as described above does not yield the significant advantages over state-of-the-art coatings obtained by using the coatings of the present invention including the adhesive layer, bottom layer, and top layer described herein.

[0077] Figure 3 shows a TEM selective region diffraction pattern confirming the formation of a fitted TiAlBN adhesive layer that mainly exhibits a cubic phase, while the TiAlBN bottom layer according to the present invention mainly exhibits a wurtzite phase. Figure 3 also shows that the TiAlBN in the bottom layer has a feathery microstructure similar to that of the TiSiN top layer in a preferred embodiment of the present invention, and this microstructure is shown to prevent cohesive fracture. Thus, the fitted TiAlBN adhesive layer mainly exhibiting a cubic phase was confirmed by the TEM observation shown in Figure 3.

[0078] Figure 4 shows an XRD comparison between a non-inventive coating (particularly a state-of-the-art cubic TiAlN / TiSiN coating) and an inventive coating containing a TiAlBN bottom layer and a TiSiN top layer, prepared according to different preferred embodiments of the present invention.

[0079] The inventors have demonstrated that, in the above-described embodiments of the present invention, a primarily wurtzite-type bottom layer, i.e., a primarily wurtzite-type TiAlBN bottom layer, offers significant advantages compared to coatings known in the prior art, as seen in the XRD of Figure 4. Furthermore, the fact that this primarily wurtzite-type bottom layer (primarily a wurtzite-type TiAlBN bottom layer in the above-described embodiments) has a feathery microstructure similar to that of TiSiN also has the advantage of providing excellent morphological integrity to prevent cohesive fracture at the interface between the bottom layer (TiAlBN bottom layer in the above-described embodiments) and the TiSiN top layer.

[0080] Specifically, the present invention relates in particular to the following: A TiAlBSiN coating deposited on the surface of a substrate 1, wherein the coating 100 comprises three distinct portions along its coating thickness: a first portion 5 is deposited directly on the surface of the substrate 1 and formed by at least one adhesive layer; a second portion 10 is deposited directly on the first portion 5 and formed by at least one support layer; and a third portion 50 is deposited directly on the second portion 10 and formed by at least one top layer. Here: At least one adhesive layer: This refers to a crystalline phase that is entirely crystalline cubic, or a mixture of crystalline phases containing a crystalline cubic phase and a crystalline hexagonal wurtzite phase, where, in the case of a mixture of crystalline phases, it mainly exhibits a cubic phase, and Containing titanium and nitrogen; and At least one supporting layer: It shows either a completely hexagonal wurtzite phase or a mixture of crystalline phases containing a crystalline cubic phase and a crystalline hexagonal wurtzite phase, and in the case of a mixture of crystalline phases, it mainly shows the wurtzite phase, and comprising titanium, aluminum, nitrogen, and at least one of boron and silicon; and At least one top tier: It exhibits either a completely crystalline cubic phase or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, where, in the case of a mixture of crystalline phases, it mainly exhibits a cubic phase, and It contains titanium, silicon and nitrogen.

[0081] The crystalline hexagonal wurtzite phase in the TiAlSiBN coating 100 contains Al and N.

[0082] Preferably, the respective thicknesses th5, th 10 and th 50 of the first coating portion, the second coating portion, and the third coating portion in the TiAlBSiN coating satisfy the following formula in micrometers or nanometers: 2 ≦ th5 × 100 / (th5 + th 10 + th 50 ) ≦ 60, and [ 15 ≦ th 510 × 100 / (th5 + th 10 + th 50 ) ≦ 60, and 20 ≦ th 50 × 100 / (th5 + th 10 + th 50 ) ≦ 60

[0083] Furthermore, the respective thicknesses th5, th 10 and th 50 of the first coating portion, the second coating portion, and the third coating portion in the TiAlBSiN coating may satisfy the following formula in micrometers or nanometers: 0.3 μm ≦ th5 + th 10 + th 50 ≦ 40 μm, and % 0.33 ≦ th 10 / th 50 ≦ 3, and / or 0.67 ≦ (th 10 + th 50 ) / th5 ≦ 49

[0084] According to a preferred embodiment of the present invention, the TiAlBSiN coating exhibits the following: The ratio of the cubic phase "cub" to the wurtzite phase "wur" in the at least one adhesive layer is greater than 0.3, that is: cub / wur ≧ 0.3; and The ratio of the cubic phase to the wurtzite phase in at least one of the supporting layers is in the range of 0.01 to 0.3, i.e., 0.01 <cub wur>0.3; and The ratio of the cubic phase "cub" to the wurtzite phase "wur" in the at least one top layer is greater than 1, i.e., "cub" / "wur" > 1, or the at least one top layer exhibits a completely crystalline cubic phase; Here, the ratio of the cubic phase to the wurtzite phase corresponds to the peak intensity ratio of (200) cubic phase to (110) wurtzite phase.

[0085] The TiAlBSiN coating preferably exhibits the following characteristics: The aforementioned at least one adhesive layer consists of the following: Titanium, aluminum, nitrogen, aluminum, at least one of boron and silicon, and unavoidable impurities of less than 1.5 atomic percent, Titanium, aluminum, boron and nitrogen, and unavoidable impurities of less than 1.5 atomic percent; and The aforementioned at least one support layer consists of the following: Titanium, aluminum, nitrogen, at least one of boron and silicon, and unavoidable impurities of less than 1.5 atomic percent, or Titanium, aluminum, boron and nitrogen, and unavoidable impurities of less than 1.5 atomic percent; and The aforementioned at least one top layer consists of the following: Titanium, silicon, nitrogen, and unavoidable impurities of less than 1.5 atomic percent.

[0086] Furthermore, the TiAlBSiN coating may be formed as follows: At least one adhesive layer is a layer mainly comprising TiN, TiAlN, TiAlBN, TiAlSiN, or TiAlBSiN, and / or At least one supporting layer is a layer mainly comprising TiAlBN, TiAlSiN, or TiAlBSiN, or composed of TiAlBN, TiAlSiN, or TiAlBSiN, and / or At least one functional layer is a layer that primarily contains or is composed of TiSiN.

[0087] According to a preferred embodiment, the TiAlBSiN coating is formed as follows. The modulus of elasticity varies along the thickness direction of the TiAlBSiN coating (100), and the minimum value of the modulus of elasticity E is along the three coating portions (5), (10), and (50). lowest This is detected at a point within the second coating portion (10) and / or at the beginning of portion 50 (the thickness of portion 50 directly above portion 10 is not sufficient for measurement, so E of portion 10 affects the measurement; this applies to the interface of all portions).

[0088] More preferably, the TiAlBSiN coating also has the following properties: The elastic modulus "E" of the at least one adhesive layer AL This range is 300 GPa to 480 GPa, i.e., 300 GPa plus or minus 15 GPa ≤ E AL <480 GPa ± 15 GPa; and The elastic modulus "E" of the at least one support layer SL This range is 250 GPa to 360 GPa, i.e., 250 GPa plus or minus 15 GPa ≤ E SL <360 GPa ± 15 GPa; and The modulus of elasticity of the at least one adhesive layer is greater than the modulus of elasticity of the at least one support layer, i.e., E AL >E SL That is the case.

[0089] The at least one support layer preferably exhibits feathery growth, and more preferably the at least one top layer also exhibits feathery growth.

[0090] The at least one adhesive layer preferably exhibits a granular or columnar growth pattern.

[0091] In a preferred embodiment, the adhesive layer of the TiAlBSiN coating is a TiAlBN adhesive layer and exhibits fine-grained growth. In this case, preferably the bottom layer is also a TiAlBN layer but exhibits feathery growth, and preferably the top layer is a TiSiN layer but exhibits feathery growth.

[0092] Preferably, the at least one adhesive layer and the at least one support layer have the same chemical elemental composition or are formed containing the same chemical elements, and if the chemical elemental compositions are not the same, the difference in atomic concentration of each chemical element is less than 10 atomic percent or less than 5 atomic percent.

[0093] The TiAlBSiN coating 100 according to the present invention preferably contains the chemical element Ti throughout its entire thickness.

[0094] The TiAlBSiN coating 100 according to the present invention preferably consists of three parts: a first part 5, a second part 10, and a third part 50.< / cub>

Claims

1. A TiAlBSin coating formed on the surface of a substrate (1), The coating (100) comprises three different coating portions along the thickness of the coating: a first portion (5), a second portion (10), and a third portion (50). The first portion (5) is formed closer to the surface of the substrate (1) than the second and third portions. The second portion (10) is formed directly on the outermost surface of the first portion (5), The third portion (50) is formed directly on the outermost surface of the second portion (10), The first portion (5) is formed of one or more layers, in either case formed by at least one adhesive layer, Part 1 (5) shows either a completely crystalline cubic phase or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, and if it is a mixture of crystalline phases, it mainly shows a cubic phase. At least one adhesive layer contains titanium and nitrogen, The second portion (10) is formed of one or more layers, in either case formed by at least one support layer, Part 2 (10) shows either a completely crystalline hexagonal wurtzite phase or a mixture of crystalline phases containing a crystalline cubic phase and a crystalline hexagonal wurtzite phase, and in the case of a mixture of crystalline phases, it mainly shows the wurtzite phase. At least one support layer comprises titanium, aluminum, nitrogen, and at least one chemical element selected from boron and silicon. The third portion (50) is formed of one or more layers, in either case formed of at least one functional layer, The third part (50) shows either a completely crystalline cubic phase or a mixture of crystalline phases including a crystalline cubic phase and a crystalline hexagonal wurtzite phase, and in the case of a mixture of crystalline phases, it mainly shows a cubic phase. At least one functional layer contains titanium, silicon, and nitrogen. A TiAlBSin coating (100) characterized in that the crystalline hexagonal wurtzite phase in the TiAlBSin coating (100) contains, for example, Al and N in the form of AlN.

2. In the TiAlBSin coating (100) according to claim 1, The thickness th of the first coating portion (5), the second coating portion (10), and the third coating portion (50) in the TiAlBSin coating (100) ５ , th １０ , th ５０ This is the th in micrometers or nanometers. ５ , th １０ and th ５０ A TiAlBSin coating characterized by satisfying the following formula, which includes the following: 2 ≤ th ５ × 100 / (th ５ + th １０ + th ５０ ) ≤ 60, and 15 ≤ th ５１０ ×100 / (th ５ +th １０ +th ５０ ) ≤ 60, and 20≦th ５０ 100 / (th) ５ +th １０ +th ５０ )≦60

3. In the TiAlBSin coating (100) according to claim 1 or claim 2, 0.3 μm ≤ th ５ +th １０ +th ５０ ≤40 μm, and 0.33 ≤ th １０ / th ５０ ≤ 3, and / or 0.67≦(th １０ +th ５０ ) / th ５ ≦49 A TiAlBSin coating characterized by the following:

4. In the TiAlBSin coating (100) according to any one of claims 1 to 3, The at least one adhesive layer is It is composed of titanium, aluminum, nitrogen, aluminum, at least one of boron and silicon, and unavoidable impurities of less than 1.5 atomic percent, or It is composed of titanium, aluminum, boron, nitrogen, and unavoidable impurities of less than 1.5 atomic percent. The aforementioned at least one support layer is It is composed of titanium, aluminum, nitrogen, at least one of boron and silicon, and unavoidable impurities of less than 1.5 atomic percent, or It is composed of titanium, aluminum, boron, nitrogen, and unavoidable impurities of less than 1.5 atomic percent. The TiAlBSin coating is characterized in that the at least one functional layer is composed of titanium, silicon, nitrogen, and unavoidable impurities of less than 1.5 atomic percent.

5. In the TiAlBSin coating (100) according to any one of claims 1 to 4, At least one adhesive layer is a layer mainly comprising TiN, TiAlN, TiAlBN, TiAlSiN, or TiAlBSiN, or a layer mainly composed of TiN, TiAlN, TiAlBN, TiAlSiN, or TiAlBSiN, and / or At least one supporting layer is a layer mainly containing TiAlBN, TiAlSiN, or TiAlBSiN, or a layer mainly composed of TiAlBN, TiAlSiN, or TiAlBSiN, and / or A TiAlBSiN coating characterized in that at least one functional layer is a layer mainly containing TiSiN, or a layer mainly composed of TiSiN.

6. In the TiAlBSin coating (100) according to any one of claims 1 to 5, The TiAlBSin coating has a chemical elemental composition expressed in atomic concentrations as follows. The elemental composition of at least one adhesive layer, preferably the entire first portion (5), is given by the following formula: (Ti) ｘ Al ｙ B ｚ Si ｗ ( ｔ N ｕ Here: x + y + z + w = ​​1, and 0 ≤ y / x ≤ 0.21, or y / (x+y) < 0.67, and 0 ≤ z + w ≤ 0.25, preferably 0 ≤ z + w ≤ 0.10, more preferably 0 < z + w ≤ 0.05, and 0 ≤ z ≤ 0.10, preferably 0 ≤ z ≤ 0.05, more preferably 0.01 ≤ z < 0.05, and 0 ≤ w ≤ 0.25, preferably 0 ≤ w ≤ 0.10, and 0.75 ≤ t / u ≤ 1.25, preferably 0.85 ≤ t / u ≤ 1.15; and / or The elemental composition of at least one bottom layer, preferably the entire second portion (10), is given by the following formula: (Ti) ａ Al ｂ B ｃ Si ｄ ( ｖ N ｑ Here: a + b + c + d = 1, and 0 ≤ b / a ≤ 2.1 and / or 0 ≤ b / (a+b) < 0.67, preferably 1 ≤ b / a ≤ 2.1, and 0 ≤ c + d ≤ 0.25, preferably 0 ≤ c + d ≤ 0.10, more preferably 0 < c + d ≤ 0.05, and 0 ≤ c ≤ 0.05, preferably 0.01 ≤ c < 0.05, more preferably 0.01 ≤ c ≤ 0.04, and 0 ≤ d ≤ 0.25, preferably 0 ≤ d ≤ 0.10, and 0.75 ≤ v / q ≤ 1.25, preferably 0.85 ≤ v / u ≤ 1.15; and / or The elemental composition of the entire third portion (50), preferably at least one functional layer, is given by the following formula: (TS ｅ Si ｆ ) ｇ N ｈ Here: e + f = 1, and 0.05 ≤ f ≤ 0.35, preferably 0.05 ≤ f ≤ 0.25, and 0.75 ≤ g / h ≤ 1.25, preferably 0.85 ≤ g / h ≤ 1.15

7. In the TiAlBSin coating (100) according to any one of claims 1 to 6, The modulus of elasticity changes along the thickness of the TiAlBSin coating (100), and the minimum value of the modulus of elasticity E along the three coating portions (5), (10), and (50) is ｌｏｗｅｓｔ A TiAlBSin coating characterized in that E is detected at a point within the second coating portion (10) and / or at the beginning of portion 50 (the thickness of portion 50 directly above portion 10 is insufficient for measurement, so E of portion 10 affects the measurement - this also applies to the interface of all portions).

8. In the TiAlBSin coating (100) according to claim 7, The elastic modulus E detected in the second part (10) ｌｏｗｅｓｔ The minimum value is in the range of 200 GPa to 360 GPa, preferably in the range of 250 GPa to 320 GPa, and more preferably in the range of 250 GPa to 360 GPa, i.e.: 200 GPa ± 15 GPa ≤ E ｌｏｗｅｓｔ ≤360 GPa ± 15 GPa, Preferably, 250 GPa ± 15 GPa ≤ E ｌｏｗｅｓｔ ≤ 320 GPa ± 15 GPa More preferably 250 GPa ± 15 GPa ≤ E ｌｏｗｅｓｔ A TiAlBSin coating characterized by having a pressure of ≤360 GPa ± 15 GPa.

9. In the TiAlBSin coating (100) according to any one of claims 1 to 8, The TiAlBSin coating is characterized in that at least one of the support layers exhibits feather-like growth.

10. In the TiAlBSin coating (100) according to any one of claims 1 to 9, The TiAlBSin coating is characterized in that at least one of the functional layers exhibits feather-like growth.

11. In the TiAlBSin coating (100) according to any one of claims 1 to 10, The TiAlBSin coating is characterized in that at least one of the adhesive layers exhibits a fine-grained or columnar growth pattern.

12. In the TiAlBSin coating (100) according to claim 11, The adhesive layer is a TiAlBN adhesive layer, and the TiAlBSin coating is characterized by exhibiting fine-grained growth.

13. In the TiAlBSin coating (100) according to any one of claims 1 to 12, The TiAlBSin coating is characterized in that the at least one adhesive layer and the at least one support layer have the same chemical elemental composition or are formed containing the same chemical elements, and if the chemical elemental compositions are not the same, the difference in atomic concentration of each chemical element is less than 10 atomic percent.

14. In the TiAlBSin coating (100) according to claim 13, A TiAlBSin coating characterized by having a difference in atomic concentration of each chemical element of less than 5 atomic percent.

15. In the TiAlBSin coating (100) according to any one of claims 1 to 14, The TiAlBSin coating (100) is a TiAlBSin coating characterized by containing Ti along the entire coating thickness.

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