A tool coating suitable for machining titanium alloys and its preparation method and tool

Abstract

This invention discloses a tool coating suitable for machining titanium alloys, its preparation method, and the tool itself, relating to the fields of surface engineering and CNC tool cutting technology. The tool coating structure includes one of the following (a) or (b): (a) a base layer, a sub-base layer, a sub-top layer, and a top layer; (b) a base layer and a top layer; wherein the base layer is (Al) a Cr b M 1‑a‑b N; the next lower layer is (Al) c Ti d Me 1‑c‑d )N / (Al a Cr b M 1‑a‑b )N / (Ti e Si 1‑e N-level loop layer; the second-level loop layer is (Ti e Si 1‑e )N / (Al c Ti d Me 1‑c‑d The N-layer circulation layer; the top layer is TX. This invention not only significantly improves the chipping resistance, wear resistance, and adhesion resistance of the cutting tool, but also significantly extends the tool's service life.

Description

Technical Field

[0001] This invention belongs to the field of surface engineering and CNC cutting tool technology, specifically a tool coating suitable for titanium alloy machining, its preparation method, and the tool itself. Background Technology

[0002] Titanium alloys are widely used in aerospace, defense, petrochemical, and biomedical fields due to their lightweight and high strength. Although the development of CNC machining technology has made titanium alloy processing increasingly mature and ensured machining accuracy, the low thermal conductivity, high hardness, and high chemical affinity of titanium alloys still lead to problems such as tool adhesion and chipping during cutting.

[0003] Currently, traditional coated cutting tools are unsuitable for machining titanium alloys due to the high affinity between the Ti element in the coating and titanium alloys (TiN, AlTiN, AlCrN), leading to rapid tool failure. However, with continuous innovation in coating technology, such as the emergence of new coatings like soft coatings, superhard coatings, multilayer coatings, and nanocomposite coatings, the application of coated cutting tools in titanium alloy machining is gradually increasing, demonstrating significant advantages. Summary of the Invention

[0004] This invention overcomes at least one limitation of existing tool coatings in terms of high-temperature resistance, anti-adhesive wear ability, toughness, and adhesion, particularly the problem of shortened tool life caused by these limitations. Therefore, the tool coating provided by this invention is particularly suitable for machining titanium alloys, not only significantly improving tool cutting life but also effectively reducing wear.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0006] The present invention provides a tool coating suitable for machining titanium alloys, the coating structure of which includes one of the following (a) or (b);

[0007] (a) Bottom layer, second bottom layer, second top layer, and top layer;

[0008] (b) Bottom layer and top layer;

[0009] Wherein, the bottom layer is (Al) a Cr b M 1-a-b N;

[0010] The next lower layer is (Al) c Ti d Me 1-c-d )N / (Al a Cr b M 1-a-b )N / (Ti e Si1-e N-level loop layer;

[0011] The second-to-top layer is (Ti) e Si 1-e )N / (Al c Ti d Me 1-c-d N-level loop layer;

[0012] The top layer is TX;

[0013] M is at least one of W, Mo, V, Si, and B;

[0014] Me is at least one of W, Mo, V, Si, and B;

[0015] T is at least one of Zr, Nb, and Cr;

[0016] X is at least one of N, C, and CN;

[0017] 0.4≤a≤0.8, 0.2≤b≤0.5, 1-ab≥0;

[0018] 0.4≤c≤0.7, 0.3≤d≤0.6, 1-cd≥0;

[0019] 0.5≤e≤0.9.

[0020] Preferably, 0.6≤a≤0.8, 0.2≤b≤0.4, and 1-ab≥0;

[0021] 0.4≤c≤0.6, 0.3≤d≤0.5, 1-cd≥0;

[0022] 0.6≤e≤0.9.

[0023] More preferably, 0.6≤a≤0.7, 0.2≤b≤0.35, and 1-ab≥0;

[0024] 0.45≤c≤0.6, 0.3≤d≤0.45, 1-cd≥0;

[0025] 0.8≤e≤0.9.

[0026] a~e, 1-ab, 1-cd, and 1-e are all atomic ratios.

[0027] Among them, (Al) a Cr b M 1-a-b )N in Al a Cr b M 1-a-b The molar ratio of Al to N is 1:1; c Ti dMe 1-c-d The molar ratio of Ti to N is 1:1; e Si 1-e The molar ratio of N to N is 1:1.

[0028] The addition of W, Mo, and V elements in this invention enables the coating to generate a Magnéli phase during tribological processes, reducing the coefficient of friction and providing excellent lubrication, thereby improving the wear resistance of the coating. The addition of Si and B elements can generate a nanocrystalline AlTiN or AlCrN coating composed of amorphous BN or SiN, achieving a fine-grained strengthening effect, improving the hardness and toughness of the coating, and extending the life of coated tools.

[0029] In this invention, the substrate selected for the tool coating is a CNC cutting tool made of cemented carbide or ceramic material.

[0030] Furthermore, the hardness of the matrix is ​​1300–1500 HV. 30 .

[0031] In this invention, the thickness of the coating is 1.5 to 4.0 μm, preferably 2.0 to 4.0 μm.

[0032] In this invention, the thickness of the bottom layer is 0.2 to 3.5 μm, preferably 0.2 to 3.1 μm.

[0033] In this invention, the thickness of the sublayer is 0.8–1.5 μm, preferably 0.9–1.5 μm.

[0034] In this invention, the thickness of the sub-top layer is 0.8–1.5 μm, preferably 0.9–1.5 μm.

[0035] In this invention, the thickness of the top layer is 0.2 to 1.5 μm, preferably 0.2 to 1.0 μm.

[0036] In this invention, the thickness ratio of the sub-bottom layer to the sub-top layer is 0.5 to 2:1, and more preferably 0.6 to 1.5:1.

[0037] In this invention, the underlying layer is composed of (Al) a Cr b M 1-a-b N was formed by deposition.

[0038] In this invention, the sub-bottom layer is composed of (Al) c Ti d Me 1-c-d )N、(Al a Cr b M 1-a-b )N and (Ti e Si1-e The three layers (N, N, and N) were formed by alternating deposition.

[0039] In this invention, the second-to-top layer is (Ti e Si 1-e )N and (Al c Ti d Me 1-c-d The two layers, N and N, are formed by alternating deposition.

[0040] In this invention, the top layer is formed by TX deposition.

[0041] In this invention, the bottom layer is a single-layer structure.

[0042] In this invention, the top layer is a single-layer structure.

[0043] In this invention, the number of loop layers in the sub-bottom layer is 0 to 180, wherein (Al) c Ti d Me 1-c-d )N / (Al a Cr b M 1-a-b )N / (Ti e Si 1-e N represents a loop layer.

[0044] In this invention, the number of loop layers in the second-to-top layer is 0 to 200, wherein (Ti e Si 1-e )N / (Al c Ti d Me 1-c-d N represents a loop layer.

[0045] In this invention, the innermost layer of the sub-bottom layer is (Al). c Ti d Me 1-c-d )N.

[0046] In this invention, the outermost layer of the sub-bottom layer is (Ti) e Si 1-e )N.

[0047] In this invention, the innermost layer of the sub-top layer is (Ti) e Si 1-e )N.

[0048] In this invention, the outermost layer of the sub-top layer is (Al) c Ti d Me 1-c-d )N.

[0049] In this invention, the outermost layer of the subbottom layer and the innermost layer of the subtop layer have the same chemical composition.

[0050] In this invention, the innermost layer of the subbottom layer and the outermost layer of the subtop layer have the same chemical composition.

[0051] The present invention also provides a method for preparing the aforementioned tool coatings suitable for titanium alloy machining, wherein the coatings are all formed by vapor deposition.

[0052] In this invention, the vapor deposition is performed using cathodic arc technology.

[0053] In this invention, the reaction gas for vapor deposition is at least one of nitrogen and acetylene.

[0054] In this invention, the arc current of the arc source for vapor deposition is 150-200A, preferably 200A.

[0055] In this invention, the bias voltage for depositing the bottom layer and the top layer in the vapor deposition is -40 to -80V, preferably -40V.

[0056] In this invention, the bias voltage for depositing the sub-bottom layer and the sub-top layer in the vapor deposition is -30 to -100V, preferably -80V.

[0057] In this invention, the deposition temperature in the vapor deposition is 400-500℃, preferably 500℃.

[0058] In this invention, the purity of the target material used for vapor deposition is ≥99.8%.

[0059] In this invention, the target material for depositing the underlying layer is Al. a Cr b M 1-a-b alloy.

[0060] In this invention, the target material for depositing the sublayer is Al. c Ti d Me 1-c-d Alloys, Al a Cr b M 1-a-b Alloys and Ti e Si 1-e alloy.

[0061] In this invention, the target material for depositing the sub-top layer is Ti. e Si 1-e Alloys and Al c Ti d Me 1-c-d alloy.

[0062] In this invention, the target material for depositing the top layer is metal T.

[0063] A cutting tool, comprising the aforementioned tool coating suitable for machining titanium alloys.

[0064] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] 1. This invention employs cathodic arc technology to deposit tool coatings and successfully incorporates alloying elements Me and M into AlTiN and AlCrN coatings through alloying control, forming AlTiMeN and AlCrMN coatings, respectively. The addition of W, Mo, and V elements promotes the formation of the Magnéli phase in the coating, which possesses excellent lubrication properties, helping to reduce friction and wear. Simultaneously, the doping of S and B elements refines the grain size, which not only enhances the hardness of the coating but also improves its toughness.

[0067] 2. This invention develops a four-layer coating structure that fully utilizes the characteristics of three coatings: AlCrMN, TiSiN, and AlTiMeN. While AlCrMN has poor thermal stability, it possesses excellent high-temperature resistance. The Cr2O3 layer formed after high-temperature oxidation is relatively dense, effectively slowing down the oxidation process. The AlTiMeN coating exhibits good thermal stability, but its high-temperature resistance is relatively poor. The TiSiN coating has excellent high-temperature resistance, but the TiO2 layer formed after high-temperature oxidation is loose and porous, failing to effectively prevent oxygen intrusion. Therefore, the underlying nanocomposite structure is needed to slow down the oxidation process. From the bottom layer to the next top layer, the coating structure macroscopically shows a gradual decrease in AlCrMN content, while the AlTiMeN and TiSiN content gradually increases. Specifically, the bottom AlCrMN coating not only provides good adhesion but also acts as the final barrier protecting the substrate, exhibiting low stress and high-temperature oxidation resistance. The next bottom layer combines the thermal stability of AlTiMeN, the high-temperature resistance of AlCrMN, and the high hardness of TiSiN, effectively synergizing these three characteristics through a nanomultilayer structure. The design logic of the next top layer is similar to that of the bottom layer, further optimizing the coating's performance. This structured design allows the coating to maintain good adhesion while combining the advantages of various materials, improving the overall performance of the coating, especially in applications at high temperatures.

[0068] 3. To further enhance the overall performance of the coating, this invention specifically employs TX, a material with anti-adhesion properties, as the top coating. Due to its excellent chemical stability, TX is unlikely to chemically react or melt-weld with titanium (Ti) metal during cutting, thus effectively preventing material adhesion. This anti-adhesion property is crucial for improving the service life of cutting tools and maintaining cleanliness during the cutting process. By applying TX material to the top layer of the coating structure, not only is the durability of the coating enhanced, but it also helps maintain the stability and performance of the cutting tool under high temperature and high pressure environments.

[0069] 4. The coating of the present invention not only exhibits excellent resistance to chipping, wear, and adhesion, but also significantly improves the service life of the cutting tool. The cutting life of the cutting tool containing the coating of the present invention is 188-240 min; in some preferred embodiments, the cutting life can reach 210-240 min; in more preferred embodiments, the cutting life can reach 216-240 min. Attached Figure Description

[0070] Figure 1 This is a schematic diagram of the tool coating structure.

[0071] Figure 2 This is a scanning electron microscope image of the tool coating in Example 15. Detailed Implementation

[0072] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0073] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0074] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is understood that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein; "0-5" is merely a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer greater than or equal to 2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0075] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0076] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0077] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0078] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0079] Unless otherwise specified, the term "or" is inclusive in this invention. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0080] Figure 1 This is a schematic diagram of the coating structure. In the diagram: L1 is the bottom layer, L2 is the subbottom layer, L3 is the subtop layer, and L4 is the top layer.

[0081] The matrix selected has a hardness of 1420 HV. 30 Carbide CNC inserts.

[0082] In L2, (Al) c Ti d Me 1-c-d )N / (Al a Cr b M 1-a-b )N / (Ti e Si 1-e The number of iterations in the N-layer is m, where m = 0 to 180.

[0083] In L3, (Ti e Si 1-e )N / (Al c Ti d Me 1-c-d The number of iterations in the N-level loop is n, where n = 0 to 200.

[0084] The deposition conditions for the following examples and comparative examples are as follows:

[0085] 1) Deposition technology: cathodic arc technology;

[0086] 2) Deposition pressure: 3.5 Pa;

[0087] 3) Reaction gases: nitrogen, acetylene. Different reaction gases are selected according to the different TX in the top layer of each embodiment and comparative example.

[0088] When X is N, nitrogen is selected; when X is C, acetylene is selected; when X is CN, a mixture of acetylene and nitrogen is selected.

[0089] 4) Deposition bias: The bias voltage for the bottom and top layers of the deposition is -40V, and the bias voltage for the subbottom and subtop layers of the deposition is -80V;

[0090] 5) Target current: The arc current of each arc source is 200A;

[0091] 6) Deposition temperature: 500℃.

[0092] Example 1

[0093] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 3.2 μm.

[0094] 1. Structure of each coating:

[0095] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0096] The top layer is ZrN.

[0097] The thickness of the bottom layer is 2.8 μm.

[0098] The thickness of the top layer is 0.4 μm.

[0099] 2. Preparation methods for each coating:

[0100] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0101] The target material for depositing the top layer is metallic Zr.

[0102] Example 2

[0103] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 3.0 μm.

[0104] 1. Structure of each coating:

[0105] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0106] The top layer is NbN.

[0107] The thickness of the bottom layer is 2.7 μm.

[0108] The thickness of the top layer is 0.3 μm.

[0109] 2. Preparation methods for each coating:

[0110] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0111] The target material for depositing the top layer is metallic Nb.

[0112] Example 3

[0113] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 3.8 μm.

[0114] 1. Structure of each coating:

[0115] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0116] The top layer is CrN.

[0117] The thickness of the bottom layer is 3.0 μm.

[0118] The thickness of the top layer is 0.8 μm.

[0119] 2. Preparation methods for each coating:

[0120] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0121] The target material for depositing the top layer is metallic Cr.

[0122] Example 4

[0123] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 2.8 μm.

[0124] 1. Structure of each coating:

[0125] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0126] The top layer is CrCN.

[0127] The thickness of the bottom layer is 2.1 μm.

[0128] The thickness of the top layer is 0.7 μm.

[0129] 2. Preparation methods for each coating:

[0130] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0131] The target material for depositing the top layer is metallic Cr.

[0132] Example 5

[0133] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 2.8 μm.

[0134] 1. Structure of each coating:

[0135] The underlying layer is (Al) 0.63 Cr 0.27 V 0.1 )N.

[0136] The top layer is ZrN.

[0137] The thickness of the bottom layer is 2.3 μm.

[0138] The thickness of the top layer is 0.5 μm.

[0139] 2. Preparation methods for each coating:

[0140] The target material for depositing the underlying layer is Al. 0.63 Cr 0.27 V 0.1 alloy.

[0141] The target material for depositing the top layer is metallic Zr.

[0142] Example 6

[0143] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 3.2 μm.

[0144] 1. Structure of each coating:

[0145] The underlying layer is (Al) 0.63 Cr 0.27 Si 0.1 )N.

[0146] The top layer is ZrN.

[0147] The thickness of the bottom layer is 2.7 μm.

[0148] The thickness of the top layer is 0.5 μm.

[0149] 2. Preparation methods for each coating:

[0150] The target material for depositing the underlying layer is Al. 0.63 Cr 0.27 Si 0.1 alloy.

[0151] The target material for depositing the top layer is metallic Zr.

[0152] Example 7

[0153] The tool coating for machining titanium alloys in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 3.4 μm.

[0154] 1. Structure of each coating:

[0155] The underlying layer is (Al) 0.63 Cr 0.27 B 0.1 )N.

[0156] The top layer is ZrN.

[0157] The thickness of the bottom layer is 3.1 μm.

[0158] The thickness of the top layer is 0.3 μm.

[0159] 2. Preparation methods for each coating:

[0160] The target material for depositing the underlying layer is Al. 0.63 Cr 0.27 B 0.1 alloy.

[0161] The target material for depositing the top layer is metallic Zr.

[0162] Example 8

[0163] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer and a top layer, and the thickness of the coating is 2.4 μm.

[0164] 1. Structure of each coating:

[0165] The underlying layer is (Al) 0.63 Cr 0.27 Si 0.067 W 0.033 )N.

[0166] The top layer is ZrN.

[0167] The thickness of the bottom layer is 2.0 μm.

[0168] The thickness of the top layer is 0.4 μm.

[0169] 2. Preparation methods for each coating:

[0170] The target material for depositing the underlying layer is Al. 0.63 Cr 0.27 Si 0.067 W 0.033 alloy.

[0171] The target material for depositing the top layer is metallic Zr.

[0172] Example 9

[0173] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer, and the thickness of the coating is 3.7 μm.

[0174] 1. Structure of each coating:

[0175] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0176] The next lower layer is (Al) 0.6 Ti 0.3 B 0.1 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0177] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 B 0.1 N-level loop layer;

[0178] The top layer is ZrN.

[0179] The thickness of the bottom layer is 0.4 μm.

[0180] The thickness of the sublayer is 1.1 μm.

[0181] The thickness of the sublayer is 1.1 μm.

[0182] The thickness of the top layer is 1.1 μm.

[0183] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0184] The number of loop layers in the lower layer is 90.

[0185] The number of loop layers in the second-to-top layer is 150.

[0186] 2. Preparation methods for each coating:

[0187] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0188] The target material for depositing the sublayer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.85 Si 0.15 alloy.

[0189] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Ti 0.85 Si0.15 alloy.

[0190] The target material for depositing the top layer is metallic Zr.

[0191] Example 10

[0192] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer, and the thickness of the coating is 3.6 μm.

[0193] 1. Structure of each coating:

[0194] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0195] The next lower layer is (Al) 0.6 Ti 0.3 B 0.1 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0196] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 B 0.1 N-cycle layer.

[0197] The top layer is ZrN.

[0198] The thickness of the bottom layer is 0.5 μm.

[0199] The thickness of the sublayer is 1.5 μm.

[0200] The thickness of the sublayer is 1.0 μm.

[0201] The thickness of the top layer is 0.6 μm.

[0202] The thickness ratio of the sub-bottom layer to the sub-top layer is 1.5:1.

[0203] The number of loop layers in the lower layer is 60.

[0204] The number of loop layers in the second-to-top layer is 100.

[0205] 2. Preparation methods for each coating:

[0206] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0207] The target material for depositing the sublayer is Al.0.6 Ti 0.3 B 0.1 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.85 Si 0.15 alloy.

[0208] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0209] The target material for depositing the top layer is metallic Zr.

[0210] Example 11

[0211] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a sub-bottom layer, a sub-top layer, and a top layer, and the thickness of the coating is 3.8 μm.

[0212] 1. Structure of each coating:

[0213] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0214] The next lower layer is (Al) 0.6 Ti 0.3 B 0.1 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0215] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 B 0.1 N-cycle layer.

[0216] The top layer is ZrN.

[0217] The thickness of the bottom layer is 0.3 μm.

[0218] The thickness of the sublayer is 1.0 μm.

[0219] The thickness of the sublayer is 1.5 μm.

[0220] The thickness of the top layer is 1.0 μm.

[0221] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.5.

[0222] The number of loop layers in the lower layer is 30.

[0223] The number of loop layers in the second-to-top layer is 50.

[0224] 2. Preparation methods for each coating:

[0225] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0226] The target material for depositing the sublayer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.85 Si 0.15 alloy.

[0227] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0228] The target material for depositing the top layer is metallic Zr.

[0229] Example 12

[0230] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a sub-bottom layer, a sub-top layer, and a top layer, and the thickness of the coating is 3.8 μm.

[0231] 1. Structure of each coating:

[0232] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0233] The next lower layer is (Al) 0.6 Ti 0.3 W 0.1 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0234] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 W 0.1 N-cycle layer.

[0235] The top layer is ZrN.

[0236] The thickness of the bottom layer is 0.5 μm.

[0237] The thickness of the sublayer is 1.1 μm.

[0238] The thickness of the sublayer is 1.1 μm.

[0239] The thickness of the top layer is 1.1 μm.

[0240] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0241] The number of loop layers in the lower layer is 90.

[0242] The number of loop layers in the second-to-top layer is 150.

[0243] 2. Preparation methods for each coating:

[0244] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0245] The target material for depositing the sublayer is Al. 0.6 Ti 0.3 W 0.1 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.85 Si 0.15 alloy.

[0246] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 W 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0247] The target material for depositing the top layer is metallic Zr.

[0248] Example 13

[0249] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a sub-bottom layer, a sub-top layer, and a top layer, and the thickness of the coating is 3.8 μm.

[0250] 1. Structure of each coating:

[0251] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0252] The next lower layer is (Al) 0.6 Ti 0.3 Mo 0.1 )N / (Al 0.7 Cr0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0253] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 Mo 0.1 N-cycle layer.

[0254] The top layer is ZrN.

[0255] The thickness of the bottom layer is 0.5 μm.

[0256] The thickness of the sublayer is 1.1 μm.

[0257] The thickness of the sublayer is 1.1 μm.

[0258] The thickness of the top layer is 1.1 μm.

[0259] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0260] The number of loop layers in the lower layer is 90.

[0261] The number of loop layers in the second-to-top layer is 150.

[0262] 2. Preparation methods for each coating:

[0263] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0264] The target material for depositing the sublayer is Al. 0.6 Ti 0.3 Mo 0.1 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.85 Si 0.15 alloy.

[0265] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 Mo 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0266] The target material for depositing the top layer is metallic Zr.

[0267] Example 14

[0268] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer.

[0269] The coating has a thickness of 3.0 μm.

[0270] 1. Structure of each coating:

[0271] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0272] The next lower layer is (Al) 0.6 Ti 0.32 Mo 0.08 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0273] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.32 Mo 0.08 N-cycle layer.

[0274] The top layer is ZrN.

[0275] The thickness of the bottom layer is 0.5 μm.

[0276] The thickness of the sublayer is 1.0 μm.

[0277] The thickness of the sublayer is 1.0 μm.

[0278] The thickness of the top layer is 0.5 μm.

[0279] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0280] The number of loop layers in the lower layer is 90.

[0281] The number of loop layers in the second-to-top layer is 150.

[0282] 2. Preparation methods for each coating:

[0283] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0284] The target material for depositing the sublayer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Al 0.7 Cr 0.3 Alloys, Ti0.85 Si 0.15 alloy.

[0285] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Ti 0.85 Si 0.15 alloy.

[0286] The target material for depositing the top layer is metallic Zr.

[0287] Example 15

[0288] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer.

[0289] The coating has a thickness of 3.9 μm.

[0290] 1. Structure of each coating:

[0291] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0292] The next lower layer is (Al) 0.6 Ti 0.32 Mo 0.08 )N / (Al 0.7 Cr 0.3 )N / (Ti 0.8 Si 0.2 N-cycle layer.

[0293] The second-to-top layer is (Ti) 0.8 Si 0.2 )N / (Al 0.6 Ti 0.32 Mo 0.08 N-cycle layer.

[0294] The top layer is ZrN.

[0295] The thickness of the bottom layer is 0.6 μm.

[0296] The thickness of the sublayer is 1.1 μm.

[0297] The thickness of the sublayer is 1.1 μm.

[0298] The thickness of the top layer is 1.1 μm.

[0299] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0300] The number of loop layers in the lower layer is 90.

[0301] The number of loop layers in the second-to-top layer is 150.

[0302] Scanning electron microscope images of the tool coating prepared in this experiment are shown below. Figure 2 The enlarged view on the right side of the figure is for illustrative purposes only; the area within the frame does not represent the actual magnified range. 2. Preparation methods for each coating:

[0303] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0304] The target material for depositing the sublayer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Al 0.7 Cr 0.3 Alloys, Ti 0.8 Si 0.2 alloy.

[0305] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Ti 0.8 Si 0.2 alloy.

[0306] The target material for depositing the top layer is metallic Zr.

[0307] Example 16

[0308] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer, and the thickness of the coating is 3.0 μm.

[0309] 1. Structure of each coating:

[0310] The underlying layer is (Al) 0.62 Cr 0.31 Si 0.07 )N.

[0311] The next lower layer is (Al) 0.57 Ti 0.38 B 0.05 )N / (Al 0.62 Cr 0.31 Si 0.07 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0312] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.57 Ti 0.38 B 0.05N-cycle layer.

[0313] The top layer is ZrN.

[0314] The thickness of the bottom layer is 0.2 μm.

[0315] The thickness of the sublayer is 0.9 μm.

[0316] The thickness of the sublayer is 0.9 μm.

[0317] The thickness of the top layer is 1.0 μm.

[0318] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0319] The number of loop layers in the lower layer is 90.

[0320] The number of loop layers in the second-to-top layer is 150.

[0321] 2. Preparation methods for each coating:

[0322] The target material for depositing the underlying layer is Al. 0.62 Cr 0.31 Si 0.07 alloy.

[0323] The target material for depositing the sublayer is Al. 0.57 Ti 0.38 B 0.05 Alloys, Al 0.62 Cr 0.31 Si 0.07 Alloys, Ti 0.85 Si 0.15 alloy.

[0324] The target material for depositing the sub-top layer is Al. 0.57 Ti 0.38 B 0.05 Alloys, Ti 0.85 Si 0.15 alloy.

[0325] The target material for depositing the top layer is metallic Zr.

[0326] Example 17

[0327] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer, and the thickness of the coating is 3.6 μm.

[0328] 1. Structure of each coating:

[0329] The underlying layer is (Al) 0.62 Cr 0.3 Si 0.05 W0.03 )N.

[0330] The next lower layer is (Al) 0.45 Ti 0.45 B 0.1 )N / (Al 0.62 Cr 0.3 Si 0.05 W 0.03 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0331] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.45 Ti 0.45 B 0.1 N-cycle layer.

[0332] The top layer is ZrN.

[0333] The thickness of the bottom layer is 0.7 μm.

[0334] The thickness of the sublayer is 1.1 μm.

[0335] The thickness of the sublayer is 1.0 μm.

[0336] The thickness of the top layer is 0.8 μm.

[0337] The thickness ratio of the sub-bottom layer to the sub-top layer is 1.1:1.

[0338] The number of loop layers in the lower layer is 90.

[0339] The number of loop layers in the second-to-top layer is 150.

[0340] 2. Preparation methods for each coating:

[0341] The target material for depositing the underlying layer is Al. 0.62 Cr 0.3 Si 0.05 W 0.03 alloy.

[0342] The target material for depositing the sublayer is Al. 0.45 Ti 0.45 B 0.1 Alloys, Al 0.62 Cr 0.3 Si 0.05 W 0.03 Alloys, Ti 0.85 Si 0.15 alloy.

[0343] The target material for depositing the sub-top layer is Al.0.45 Ti 0.45 B 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0344] The target material for depositing the top layer is metallic Zr.

[0345] Example 18

[0346] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a subbottom layer, a subtop layer, and a top layer, and the thickness of the coating is 2.6 μm.

[0347] 1. Structure of each coating:

[0348] The underlying layer is (Al) 0.6 Cr 0.3 V 0.1 )N.

[0349] The next lower layer is (Al) 0.6 Ti 0.3 B 0.1 )N / (Al 0.6 Cr 0.3 V 0.1 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0350] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.3 B 0.1 N-cycle layer.

[0351] The top layer is ZrN.

[0352] The thickness of the bottom layer is 0.3 μm.

[0353] The thickness of the sublayer is 1.0 μm.

[0354] The thickness of the sublayer is 1.0 μm.

[0355] The thickness of the top layer is 0.3 μm.

[0356] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0357] The number of loop layers in the lower layer is 90.

[0358] The number of loop layers in the second-to-top layer is 150.

[0359] 2. Preparation methods for each coating:

[0360] The target material for depositing the underlying layer is Al. 0.6 Cr 0.3 V 0.1 alloy.

[0361] The target material for depositing the sublayer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Al 0.6 Cr 0.3 V 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0362] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.3 B 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0363] The target material for depositing the top layer is metallic Zr.

[0364] Example 19

[0365] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a bottom layer, a second top layer, and a top layer, and the thickness of the coating is 3.2 μm.

[0366] 1. Structure of each coating:

[0367] The underlying layer is (Al) 0.6 Cr 0.3 B 0.1 )N.

[0368] The next lower layer is (Al) 0.6 Ti 0.32 Mo 0.08 )N / (Al 0.6 Cr 0.3 B 0.1 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0369] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.32 Mo 0.08 N-cycle layer.

[0370] The top layer is ZrN.

[0371] The thickness of the bottom layer is 0.4 μm.

[0372] The thickness of the sublayer is 1.2 μm.

[0373] The thickness of the sublayer is 1.2 μm.

[0374] The thickness of the top layer is 0.4 μm.

[0375] The thickness ratio of the sub-bottom layer to the sub-top layer is 1:1.

[0376] The number of loop layers in the lower layer is 90.

[0377] The number of loop layers in the second-to-top layer is 150.

[0378] 2. Preparation methods for each coating:

[0379] The target material for depositing the underlying layer is Al. 0.6 Cr 0.3 B 0.1 alloy.

[0380] The target material for depositing the sublayer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Al 0.6 Cr 0.3 B 0.1 Alloys, Ti 0.85 Si 0.15 alloy.

[0381] The target material for depositing the sub-top layer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Ti 0.85 Si 0.15 alloy.

[0382] The target material for depositing the top layer is metallic Zr.

[0383] Example 20

[0384] The tool coating for titanium alloy machining in this embodiment consists of a bottom layer, a bottom layer, a second top layer, and a top layer, and the thickness of the coating is 3.2 μm.

[0385] 1. Structure of each coating:

[0386] The underlying layer is (Al) 0.6 Cr 0.3 B 0.1 )N.

[0387] The next lower layer is (Al) 0.6 Ti 0.32 Mo 0.08 )N / (Al 0.6 Cr 0.3 B0.1 )N / (Ti 0.85 Si 0.15 N-cycle layer.

[0388] The second-to-top layer is (Ti) 0.85 Si 0.15 )N / (Al 0.6 Ti 0.32 Mo 0.08 N-cycle layer.

[0389] The top layer is ZrC.

[0390] The thickness of the bottom layer is 0.3 μm.

[0391] The thickness of the sublayer is 1.1 μm.

[0392] The thickness of the sublayer is 1.0 μm.

[0393] The thickness of the top layer is 0.8 μm.

[0394] The thickness ratio of the sub-bottom layer to the sub-top layer is 1.1:1.

[0395] The number of loop layers in the lower layer is 90.

[0396] The number of loop layers in the second-to-top layer is 150.

[0397] 2. Preparation methods for each coating:

[0398] The target material for depositing the underlying layer is Al. 0.6 Cr 0.3 B 0.1 alloy.

[0399] The target material for depositing the sublayer is Al. 0.6 Ti 0.32 Mo 0.08 Alloys, Al 0.6 Cr 0.3 M 0.1 Alloys and Ti 0.85 Si 0.15 alloy.

[0400] The target material for depositing the second-layer top layer is Ti. 0.85 Si 0.15 Alloys and Al 0.6 Ti 0.32 Mo 0.08 alloy.

[0401] The target material for depositing the top layer is metallic Zr.

[0402] Comparative Example 1

[0403] The tool coating of this comparative example, suitable for machining titanium alloys, consists of an underlayer with a thickness of 3.0 μm.

[0404] 1. Structure of each coating:

[0405] The underlying layer is (Al) 0.67 Ti 0.33 )N.

[0406] The thickness of the bottom layer is 3.0 μm.

[0407] 2. Preparation methods for each coating:

[0408] The target material for depositing the underlying layer is Al. 67 Ti 33 alloy.

[0409] Comparative Example 2

[0410] The tool coating of this comparative example, suitable for machining titanium alloys, consists of an underlayer with a thickness of 3.0 μm.

[0411] 1. Structure of each coating:

[0412] The underlying layer is (Al) 0.7 Cr 0.3 )N.

[0413] The thickness of the bottom layer is 3.0 μm.

[0414] 2. Preparation methods for each coating:

[0415] The target material for depositing the underlying layer is Al. 0.7 Cr 0.3 alloy.

[0416] Effect Example

[0417] The cutting tools containing the coatings of the above embodiments and comparative examples were subjected to cutting tests under the following conditions, and the test results are shown in Table 1.

[0418] Flat end mill: D6.0R0.5x16xd6x50-4T;

[0419] Machining method: Side milling;

[0420] Cutting speed Vc: 170 m / min;

[0421] Feed rate fz: 0.056 mm / rev;

[0422] Depth of cut Ap: 8mm;

[0423] Cut width Ae: 0.4mm;

[0424] Cooling method: Water cooling;

[0425] Workpiece material: Ti-6Al-4V (TC4).

[0426] Table 1

[0427]

[0428] As can be seen from the above embodiments and comparative examples, in embodiments 1 to 4, the coating surface has an anti-adhesion top coating design, which makes the coated tool have a good adhesive wear effect during the cutting process, and thus the cutting life of the coated tool is slightly longer.

[0429] Examples 5, 7, and 8 have good wear resistance and lubricity due to alloy doping in the coating substrate, thus improving the lifespan. However, in Example 6, the excessive addition of Si resulted in an excessively high amorphous content in the coating, which reduced the coating hardness and thus led to a slightly worse effect.

[0430] Examples 9-11 optimized the number of cycles for the sub-bottom and sub-top layers. The higher the number of cycles, the thinner the thickness of each layer, and the better the strengthening effect of the nano-multilayer structure, thus resulting in a longer cutting life for the coated tool.

[0431] Examples 12-15 compared the Si content in doped metals Me and TiSiN. It was found that the cutting life of the coated tools was basically the same for W and Mo at the same doping content (Examples 12 and 13). However, with slightly lower Mo doping, the coating showed a slight advantage. Overall, the difference was not significant. However, the increase in Si content had a greater impact on the coating's lifespan. When the Si content increased to 20 at% (Example 15), the cutting life of the coated tools increased. This may be because W and Mo have basically the same lubricity, but the increase in Si content has a greater impact on the nanocomposite structure of the TiSiN coating.

[0432] Examples 16-20 show that V, Si, and B were doped into AlCrN, and acetylene was added to ZrN. The results show that the doping elements in AlCrN have a certain good effect on the cutting life of the coating, while the surface ZrCN, relative to ZrN, basically performs the same in actual cutting process.

[0433] Compared with the comparative example, the above embodiments show significant advantages in cutting performance, both in terms of structural optimization and coating composition optimization. In particular, the anti-chipping properties of the coated tools are significantly enhanced during the machining of titanium alloys.

[0434] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this invention. It should be understood that the above descriptions are merely specific embodiments of this invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A tool coating suitable for machining titanium alloys, characterized in that, Its coating structure includes a base layer, a sub-base layer, a sub-top layer, and a top layer; Wherein, the bottom layer is (Al) a Cr b M 1-a-b )N; The next lower layer is (Al) c Ti d Me 1-c-d )N / (Al a Cr b M 1-a-b )N / (Ti e Si 1-e N-level loop layer; The second-to-top layer is (Ti) e Si 1-e )N / (Al c Ti d Me 1-c-d N-level loop layer; The top layer is TX; M is at least one of W, Mo, V, Si, and B; Me is at least one of W, Mo, V, Si, and B; T is at least one of Zr, Nb, and Cr; X is at least one of N, C, and CN; 0.4≤a≤0.8, 0.2≤b≤0.5, 1-ab≥0; 0.4≤c≤0.7, 0.3≤d≤0.6, 1-cd≥0; 0.5≤e≤0.9。 2. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, The substrate for the tool coating is a CNC insert made of cemented carbide or ceramic material, wherein the hardness of the substrate is 1300~1800 HV. 30 .

3. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, At least one of the following conditions (1) to (4) must be met: (1) The thickness of the bottom layer is 0.2~3.5μm; (2) The thickness of the sublayer is 0.8~1.5μm; (3) The thickness of the sub-top layer is 0.8~1.5μm; (4) The thickness of the top layer is 0.2~1.5μm.

4. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, At least one of the following conditions (1) to (2) must be met: (1) The thickness of the coating is 1.5~4.0μm; (2) The ratio of the thickness of the sub-bottom layer and the sub-top layer coating is 0.5~2:

1.

5. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, At least one of the following conditions (1) to (4) must be met: (1) The bottom layer is a single-layer structure; (2) The top layer is a single-layer structure; (3) The number of loop layers in the second-lowest layer is 0 to 180, and this number of loop layers is not zero; wherein, (Al) c Ti d Me 1-c-d )N / (Al a Cr b M 1-a-b )N / (Ti e Si 1-e N represents a loop layer; (4) The number of loop layers in the second-to-top layer is 0 to 200, and this number of loop layers is not zero; where, (Ti e Si 1-e )N / (Al c Ti d Me 1-c-d N represents a loop layer.

6. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, At least one of the following conditions (1) to (4) must be met: (1) The innermost layer of the sub-bottom layer is (Al) c Ti d Me 1-c-d )N; (2) The outermost layer of the sub-bottom layer is (Ti) e Si 1-e )N; (3) The innermost layer of the sub-top layer is (Ti) e Si 1-e )N; (4) The outermost layer of the sub-top layer is (Al) c Ti d Me 1-c-d )N.

7. The tool coating suitable for machining titanium alloys as described in claim 1, characterized in that, At least one of the following conditions (1) to (2) must be met: (1) The outermost layer of the subbottom layer and the innermost layer of the subtop layer have the same chemical composition; (2) The innermost layer of the subbottom layer has the same chemical composition as the outermost layer of the subtop layer.

8. The method for preparing a tool coating suitable for machining titanium alloys as described in any one of claims 1 to 7, characterized in that, The coatings are all formed by vapor deposition; Wherein, the vapor deposition satisfies at least one of the following conditions (1) to (7): (1) The vapor deposition process employs cathodic arc technology; (2) The reaction gas for the vapor deposition is nitrogen or acetylene; (3) The arc current of the arc source for vapor deposition is 100~200A; (4) The vacuum degree of the vapor deposition is 1.0~6.0 Pa; (5) The bias voltage for depositing the bottom layer and the top layer in the vapor deposition is -30~-100V; (6) The bias voltage for depositing the sub-bottom layer and the sub-top layer in the vapor deposition is -30~-200V; (7) The deposition temperature in the vapor deposition is 400~600℃.

9. The method for preparing a tool coating suitable for machining titanium alloys as described in claim 8, characterized in that, At least one of the following conditions (1) to (5) must be met: (1) The purity of the target materials used in the vapor deposition is ≥99.8%; (2) The target material for depositing the underlying layer is Al. a Cr b M 1-a-b alloy; (3) The target material for depositing the sublayer is Al. c Ti d Me 1-c-d Alloys, Al a Cr b M 1-a-b Alloys and Ti e Si 1-e alloy; (4) The target material for depositing the sub-top layer is Ti. e Si 1-e Alloys and Al c Ti d Me 1-c-d alloy; (5) The target material for depositing the top layer is metal T.

10. A cutting tool comprising the cutting tool coating for machining titanium alloys as described in claims 1 to 7.

Images