A composite coated cutting tool and a method of making the same

Abstract

The present application relates to the field of milling cutter coating design, in particular to a kind of composite coating cutter and its preparation method.The cutter includes cemented carbide substrate and composite coating;The composite coating is prepared by arc ion plating, and from substrate to outside, it includes XN transition layer, AlXN intermediate layer, nano-composite functional layer;X is Ti and / or Cr.Its preparation method includes using arc ion plating to prepare each coating.The present application improves the service life of coating by designing multilayer coating, and avoids the problem that nano-composite functional layer falls off early due to low adhesion by designing transition layer and intermediate layer.The present application can effectively improve the performance of cutter in dry machining, reduce the wear length of relief surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of milling insert coating design, in particular to a composite coating tool and a preparation method thereof. BACKGROUND

[0002] In the field of machining, milling inserts play an extremely important role, and are used for work in the process of milling metals. However, with the extension of machining time, especially in the dry machining process which is emerging under the current emphasis on environmental friendliness, the tool will appear phenomena such as sticking, chipping and wear, which will cause the tool to fail rapidly due to oxidation and wear. In order to prolong the service life of the tool, a hard coating layer is generally coated on the surface of the hard alloy tool, from the traditional XN (X is Ti or Cr) and AlXN single-layer coating to the later multi-layer coating (such as patent application CN118957492A). The coating should have properties such as high hardness, high wear resistance and high oxidation resistance, which help to improve the service time of the insert and improve the machining performance of the insert.

[0003] AlXSiN coating is a coating formed by introducing a fourth element Si into the AlXN coating, which has a wide application in the field of titanium alloy cutting. AlXSiN coating has a nanocrystalline or even amorphous structure, which provides the AlXSiN coating with high hardness, but if this coating is directly deposited on the substrate, it will have low bonding force. Therefore, in the application process, the AlXSiN coating is often combined with other coatings such as XN and AlXN to form a composite coating for use, which can significantly improve the problem of coating bonding force.

[0004] At present, oxidation failure is one of the important reasons for the failure of machining inserts, which is mainly caused by the reaction between the insert and oxygen in the air due to the rapid rise in temperature during dry machining. The oxidation layer is easy to fall off from the coating after the reaction occurs, thereby exposing the substrate, and ultimately causing the tool to fail. At the same time, bonding force, hardness and wear resistance are also key parameters of tool performance, so it is meaningful to design a tool that takes into account oxidation resistance, hardness and wear resistance. SUMMARY

[0005] In order to solve the problems existing in the prior art, the purpose of the present application is to provide a composite coating tool preparation method. The preparation method provided by the present application takes into account wear resistance, hardness, bonding force and oxidation resistance, and can solve at least one aspect of the problems or defects mentioned in the background art.

[0006] In order to achieve the above-mentioned application purpose, the present application provides the following technical scheme:

[0007] The composite coating cutter of the present application comprises a cemented carbide substrate and a composite coating on the substrate; the composite coating is prepared by arc ion plating, and comprises, from the substrate outward, an XN transition layer, an AlXN intermediate layer deposited on the surface of the XN transition layer, a nanocomposite functional layer deposited on the surface of the AlXN intermediate layer, and an AlXN surface layer deposited on the surface of the nanocomposite functional layer.

[0008] The nanocomposite functional layer is selected from one of AlXN / AlXSiN nanocomposite functional layers and AlX1N / AlX2N nanocomposite functional layers; X is Ti and / or Cr; X1 is Ti or Cr, X2 is Ti or Cr, and the selected elements of X1 and X2 are different.

[0009] As one of the preferred solutions, the nanocomposite functional layer surface is further deposited with an AlXN surface layer.

[0010] The overall thickness of the composite coating is 1.60 to 2.0 μm.

[0011] In the present application, the thickness of the XN transition layer is 0.8-0.12 μm, the thickness of the AlXN intermediate layer is 0.25-0.4 μm, the thickness of the nanocomposite functional layer deposited on the surface of the AlXN intermediate layer is 0.5-0.8 μm, and when necessary, an AlXN surface layer with a thickness of 0.3-0.45 μm can be deposited on the surface of the nanocomposite functional layer. The thickness of each coating is controlled in order to seek a balance among various properties. If the XN transition layer is too thin, it can result in insufficient bonding force, early peeling of the coating, and the like. If the XN transition layer is too thick, it can result in introduction of excessive internal stress, affecting the overall toughness, and the like. If the AlXN intermediate layer is too thin, it can result in failure to relieve stress, resulting in poor bonding force between the functional layer and the transition layer, and the like. If the AlXN intermediate layer is too thick, it can result in improvement of the bonding force, but sacrifice of various mechanical properties, and the like. If the nanocomposite functional layer is too thin, it can result in insufficient hardness, wear resistance, and the like. If the AlXN / AlXSiN nanocomposite functional layer is too thick, it can result in insufficient bonding force, early peeling of the coating, and the like. The AlXN surface layer deposited on the surface of the nanocomposite functional layer is helpful to improve the surface toughness of the product and increase the impact resistance of the product.

[0012] The present application provides a preparation method of a nanogradient composite cutter, comprising the following steps:

[0013] Step 1: argon etching is performed on the surface of the cutter substrate, and after etching, an XN transition layer is deposited.

[0014] Step 2: first arc ion plating is performed on the surface of the product obtained in step (1) to obtain an AlXN intermediate layer.

[0015] Step 3: a second arc ion plating is performed on the surface of the product obtained in step (2) to obtain a nanocomposite functional layer. X is Ti and / or Cr.

[0016] In actual application, the WC-Co substrate is subjected to sand blasting and cleaning treatment. Then, argon etching treatment is performed, and after etching, the deposition of the transition layer XN is performed.

[0017] In the present application, the argon etching treatment comprises: adjusting the basic cavity pressure to 1.0×10 -3 Pa by a vacuum pump, heating the cavity temperature to 550℃ and keeping for 30 min, rotating the support at a speed of 3.5 r / min, first introducing N2 and Ar with a volume ratio of 1:2, adjusting the cavity pressure to 4 Pa, arc ionizing Ar + , and bombarding and cleaning the blade substrate under a bias voltage of -800 V for 15 min. Then, the N2 channel is closed, the bias voltage is kept at -800 V, the H2 channel (flow rate of 30 sccm) is opened, H2 is ionized to clean and activate the surface of the target material for 10 min. Preferably, the target material is X.

[0018] Preferably, in step (1), the target current for depositing the transition layer is 100-140 A, the substrate bias voltage is -700 to -900 V, and the deposition time is 2-5 min. In step (1), the XN transition layer is deposited by using at least one of a titanium target and a chromium target.

[0019] Preferably, in step (2), the target current for the first arc ion plating is 120-140 A, the substrate bias voltage is -80 to -100 V, and the first arc ion plating time is 15-25 min.

[0020] Preferably, in step (3), the second arc ion plating is performed twice: the first time, the target current is 120-140 A, the substrate bias voltage is -85 to -105 V, and the arc ion plating time is 50-60 min; the second time, the target current is 120-140 A, the substrate bias voltage is -90 to -110 V, and the arc ion plating time is 60-80 min.

[0021] Preferably, a third arc ion plating is performed on the surface of step (3) to obtain an AlXN surface layer; the target current for the third arc ion plating is 120-140 A, the substrate bias voltage is -100 to -120 V, and the third arc ion plating time is 70-80 min.

[0022] Preferably, in step (2), at least one of an aluminum-titanium target and an aluminum-chromium target is used to deposit the AlXN intermediate layer.

[0023] Preferably, the target material used in the deposition of the AlXN / AlXSiN nanocomposite functional layer in step (3) is selected from at least one of an AlX target and an AlXSi target.

[0024] Preferably, the target material used in the deposition of the AlXN layer is selected from at least one of an aluminum titanium target and an aluminum chromium target.

[0025] In the present application, the target material is selected from an X target, two AlX targets, and an AlXSi target, wherein the molar ratio of Al to X in the two AlX targets is 67:33, and one of the other two target materials is selected from the other two target materials;

[0026] or the target material is selected from an X target and two AlX targets, wherein the molar ratio of Al to Ti in the two AlX targets is 67:33, and the molar ratio of Al to Cr in the two AlX targets is 70:30.

[0027] wherein the molar ratio of AlXSi is 60:30:10; the AlX No. 1 target and the AlXSi target are symmetrically placed when placed; and the X target, the AlX No. 1 target and the AlX No. 2 target, the AlXSi target and the AlX No. 1 target, and the AlX No. 1 target and the AlX No. 2 target are respectively turned on from etching to the first, second, and third arc ion plating.

[0028] The purity of the target material is greater than or equal to 99.9 wt.%.

[0029] When the target material is selected from a Ti target, an AlX target, and an AlXSi target (the purity of the target material is 99.9 wt.%), wherein the molar ratio of Al to Ti in the two AlX targets is 67:33, and one of the other two target materials is selected from the other two target materials, wherein the molar ratio of AlXSi is 60:30:10; the AlX No. 1 target and the AlXSi target are symmetrically placed when placed. The Ti target, the AlX No. 1 target and the AlX No. 2 target, the AlXSi target and the AlX No. 1 target, and the AlX No. 1 target and the AlX No. 2 target are respectively turned on from etching to the first, second, and third arc ion plating.

[0030] Preferably, the nitrogen flow rate is 300-500 sccm.

[0031] The present application also provides a coated tool comprising a blade substrate and a composite coating prepared by the above method; the composite coating comprises an XN transition layer, an AlXN intermediate coating deposited on the surface of the TiN transition layer, and a nanocomposite functional layer deposited on the AlXN intermediate coating.

[0032] As preferred, an AlXN surface layer deposited on the nanocomposite functional layer can also be provided.

[0033] The coating disclosed in the present application has a substrate comprising a WC-Co-based hard alloy milling blade, and as preferred, the binder phase of the hard alloy tool contains elements such as Ta and Nb.

[0034] Further preferably, the model of the insert substrate comprises APMT1135, APMT1604, RPMT1003 and RDMW1204.

[0035] Compared with the prior art, the present application has the following advantages: the present application provides a composite coated cutting tool and a preparation method thereof, the composite coated cutting tool prepared by the arc ion plating process comprises a hard alloy cutting tool substrate and a composite coating on the substrate: Si and other elements are added as a nanocomposite functional layer to refine the grain size to the nanocrystalline level to provide higher hardness and oxidation resistance; XN is used as a transition layer, AlXN is used as a surface layer and an intermediate layer to improve the adhesion of the nanocomposite functional layer. Therefore, the present application has good mechanical properties, oxidation resistance and adhesion in general, and the composite coated cutting tool has the advantages of simple preparation process, easy operation and suitability for large-scale production. The results of the examples show that the flank wear length of the single-layer coating comparative example is higher than that of the multilayer nanocomposite coating example after milling TC4 titanium alloy for 840 m under the condition of high-speed milling at 140 m / min. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A schematic diagram of a nanomultilayer composite coating designed by the present application.

[0037] Figure 2 A metallographic photograph of the product after cutting according to Example 3 of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the drawings and examples of the present application will be described in detail below, obviously, the described examples are only a part of the examples of the present application, not all the examples. Based on the examples of the present application, all the examples obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0039] Example 1

[0040] (1) A hard alloy insert substrate (model APMT1604) was used to clean various impurities on the surface by sandblasting, the sandblasting time was 3 s, the pressure was 0.2 MPa, after sandblasting, the substrate was placed in an ultrasonic water tank for acid washing, alkali washing and ultrapure water washing for 15 s each, then the residual liquid was blown off, the substrate was dried in a drying oven at 90℃ for 60 min, and then was sent into an arc ion plating chamber and placed on a rotating support.

[0041] (2) Put Ti target, AlTi target and AlTiSi target (the purity of the target material is 99.9 wt.%) at the same time, among which two AlTi targets, the ratio of Al to Ti is 67:33 (molar ratio); the other two target materials are one each, among which the ratio of AlTiSi is 60:30:10 (molar ratio); the AlTi No. 1 target and the AlTiSi target are symmetrically placed when placed. Adjust the basic cavity pressure to 1.0 x 10 -3 Pa, heat the cavity temperature to 550℃ and keep for 30 min, the rotating support speed is 3.5 r / min, first introduce N2 and Ar with a volume ratio of 1:2, adjust the cavity pressure to 4 Pa, arc ionize Ar + , bombard and clean the blade substrate under a bias of -800 V for 15 min, close the N2 channel, keep the bias at -800 V, open the H2 channel (flow rate 30 sccm) to ionize H2 to clean and activate the surface of the target material for 10 min.

[0042] (3) After etching the surface of the substrate, deposit a TiN transition layer (thickness about 0.1 microns), introduce 200 sccm of N2, keep the cavity pressure at 4 Pa, keep the substrate bias at -800 V and the target current at 120 A for the Ti target, for 3 min. At this time, the AlTi target and the AlTiSi target are not powered.

[0043] (4) Deposit an AlTiN intermediate layer (thickness about 0.3 microns), increase the cavity pressure to 25 Pa, keep the target current of AlTi No. 1 target and AlTi No. 2 target at 140 A and the substrate bias at -80 V, for 20 min, other parameters remain unchanged. At this time, the Ti target and the AlTiSi target are not powered.

[0044] (5) Deposit AlTiN / AlTiSiN nanocomposite functional layer (thickness about 0.6 microns), keep the target current of AlTiSi target and AlTi No. 1 target at 140 A and the substrate bias at -85 V, for 55 min. Then change the substrate bias of each to -90 V, for 70 min, other parameters remain unchanged. At this time, the Ti target is not powered.

[0045] (6) Deposit AlTiN surface layer (thickness about 0.35 microns), keep the target current of AlTi No. 1 target and AlTi No. 2 target at 140 A and the substrate bias at -100 V, for 75 min, other parameters remain unchanged, finally the total thickness of the coating is about 1.35 μm.

[0046] Example 2

[0047] (1) The same as example 1.

[0048] (2) Same as example 1.

[0049] (3) Same as example 1.

[0050] (4) Change the target current of two targets to 120 A, other parameters are same as example 1, the thickness of the deposited AlTiN intermediate layer is about 0.32 microns.

[0051] (5) Change the target current of two targets to 120 A, other parameters are same as example 1, the thickness of the deposited AlTiN / AlTiSiN nanocomposite functional layer is about 0.65 microns.

[0052] (6) Change the target current of two targets to 120 A, other parameters are same as example 1, the thickness of the deposited AlTiN surface layer is about 0.37 microns, and the total thickness of the finally obtained coating is about 1.45 μm.

[0053] Example 3

[0054] (1) Same as example 1.

[0055] (2) Same as example 1.

[0056] (3) Same as example 1.

[0057] (4) Change the target current of two targets to 130 A, other parameters are same as example 1, the thickness of the deposited AlTiN intermediate layer is about 0.33 microns.

[0058] (5) Change the target current of two targets to 130 A, other parameters are same as example 1, the thickness of the deposited AlTiN / AlTiSiN nanocomposite functional layer is about 0.7 microns.

[0059] (6) Change the target current of two targets to 130 A, other parameters are same as example 1, the thickness of the deposited AlTiN surface layer is about 0.4 microns, and the total thickness of the finally obtained coating is about 1.52 μm.

[0060] Example 4

[0061] (1) Same as example 1.

[0062] (2) Same as example 1.

[0063] (3) Same as example 1.

[0064] (4) Change the target current of two targets to 130 A, other parameters are same as example 1, the thickness of the deposited AlTiN intermediate layer is about 0.33 microns.

[0065] (5) Change the substrate bias of two targets, the substrate bias of the first deposition is -105 V, the substrate bias of the second deposition is -110 V, and other parameters are the same as those in Example 1, the thickness of the deposited AlTiN / AlTiSiN nanocomposite functional layer is about 0.74 microns.

[0066] (6) Change the substrate bias of two targets to -120 V, and other parameters are the same as those in Example 1, the thickness of the deposited AlTiN surface layer is about 0.43 microns, and the total thickness of the finally obtained coating is about 1.67 μm.

[0067] Comparative Example 1

[0068] The AlTiN gradient coating of the comparative example is composed of a TiN transition layer and an AlTiN layer, and is prepared by the following method:

[0069] (1) The hard alloy milling tool piece substrate is cleaned of various impurities on the surface by sandblasting, the sandblasting time is 3 s, the pressure is 0.2 MPa, after sandblasting, the tool piece substrate is placed in an ultrasonic water tank for acid washing → alkali washing → ultrapure water for 15 min each, the residual liquid is blown off, and the tool piece substrate is dried in an oven at 90 ℃ for 60 min and then sent into an arc ion plating chamber. A vacuum pump is used to adjust the basic cavity pressure of the vacuum chamber to 1.0 x 10 -3 Pa, the chamber temperature is heated to 550 ℃ and kept for 30 min, the rotating support rotates at a speed of 3.5 r / min, N2 and Ar are first introduced, Ar ions are arc ionized, + under a bias voltage of -800 V, the tool piece substrate is bombarded and cleaned for 15 min. The N2 channel is closed, the bias voltage is kept at -800 V, and the H2 channel is opened to ionize H + ions to clean and activate the surface of the target material for 8 min.

[0070] (2) Deposition of TiN transition layer: close the H2 channel, open the N2 channel, the channel flow is 400 sccm, the cavity pressure in the furnace is 3 Pa, the Ti target is powered on, the target current is 140 A, and the substrate bias is -800 V. A TiN transition layer is deposited on the substrate surface while etching the substrate surface for 5 min, and the thickness is about 0.1 μm.

[0071] (3) Deposition of AlTiN coating: open the AlTi target current, the target current is 140 A, the deposition temperature is 550 ℃, the cavity pressure is 2 Pa, and the substrate bias is -120 V. An AlTiN coating is prepared on the surface of the TiN coating, the deposition time is 200 min, and the thickness is 1.5 μm.

[0072] The coating prepared above is subjected to milling cutter cutting experiment, the cutting material is TC4 titanium alloy, the cutting speed is 140 m / min, the feed rate is 0.1 mm / r, the cutting depth is 0.5 mm, and the cutting width is 5 mm. After cutting for 840 m, all the milling cutters are placed into a metallographic photograph for comparison of the length of the flank wear, and the final results are shown in Table 1.

[0073] .

[0074] As can be seen from the results in the table, the flank wear of the comparative examples is higher than that of each embodiment after high-strength dry machining of the difficult-to-machine material TC4 titanium alloy, indicating that the embodiments have a good effect on reducing tool wear in dry machining.

[0075] According to the above test conditions, when the test length is 1680 m, the length of the tool flank wear of Comparative Example 1 is 163.9 μm; the length of the tool flank wear of Example 1 is 146.2 μm; the length of the tool flank wear of Example 2 is 137.6 μm; the length of the tool flank wear of Example 3 is 152.9 μm; and the length of the tool flank wear of Example 4 is 138 μm.

[0076] Example 5

[0077] (1) The hard alloy blade substrate (model APMT1604) is used to spray sand to clean various impurities on the surface, the sandblasting time is 3 s, the pressure is 0.2 MPa, after sandblasting, the substrate is placed in an ultrasonic water tank for acid washing, alkali washing and ultrapure water washing for 15 s each, and then the residual liquid is blown off, the substrate is dried in a drying oven at 90°C for 60 min, and then placed on a rotating support in an arc ion plating chamber.

[0078] (2) The Cr target, the AlTi target and the AlCr target (the purity of the target material is 99.9 wt.%) are placed at the same time, among them, two AlTi targets, the ratio of Al to Ti is 67:33 (molar ratio); the other two targets are one each, among them, the ratio of AlCr is 70:30 (molar ratio); when placed, the AlTi No. 1 target and the AlCr target are placed symmetrically. The basic cavity pressure is adjusted to 1.0 x 10 -3 Pa by a vacuum pump, the cavity temperature is heated to 550°C and kept for 30 min, the rotating support rotates at a speed of 3.5 r / min, N2 and Ar with a volume ratio of 1:2 are first introduced, the cavity pressure is adjusted to 4 Pa, Ar + is ionized by arc at a bias voltage of -800 V to bombard and clean the blade substrate for 15 min, the N2 channel is closed, the bias voltage is kept at -800 V, the H2 channel (flow rate 30 sccm) is opened to ionize H2 to clean and activate the surface of the target material for 10 min.

[0079] (3) After etching the substrate surface, deposit a TiN transition layer, introduce 200 sccm of N2, maintain the chamber pressure at 4 Pa, maintain the substrate bias of the Cr target at -800 V and the target current at 120 A, and continue for 3 min.

[0080] (4) Deposit an AlCrN intermediate layer, increase the chamber pressure to 25 Pa, maintain the target current of the AlTi No. 1 and No. 2 targets at 120 A and the substrate bias at -85 V, and continue for 20 min, while keeping other parameters unchanged.

[0081] (5) Deposit an AlTiN / AlCrN nanocomposite functional layer, maintain the target current of the AlCr target at 120 A and the substrate bias at -90 V, and maintain the target current of the AlTi target at 120 A and the substrate bias at -85 V for 55 min. Then change the substrate bias of each target to -95 V and -90 V, respectively, and continue for 70 min, while keeping other parameters unchanged.

[0082] (6) Deposit an AlTiN surface layer, maintain the target current of the AlTi No. 1 and No. 2 targets at 140 A and the substrate bias at -100 V, and continue for 75 min, while keeping other parameters unchanged. Finally, the total thickness of the obtained coating is about 2.02 μm.

[0083] Example 6

[0084] (1) Use a cemented carbide blade substrate (model APMT1604) to clean the surface of various impurities by sandblasting, with a sandblasting time of 3 s and a pressure of 0.2 MPa. After sandblasting, place the substrate in an ultrasonic water tank and sequentially perform acid washing, alkali washing, and ultrapure water washing for 15 s each. After washing, blow off the residual liquid, and then place the substrate in an electric arc ion plating chamber after drying in a drying oven at 90°C for 60 min.

[0085] (2) Place Cr targets, AlTi targets, and AlCr targets (the purity of the targets is 99.9 wt.%) at the same time, wherein there are two AlTi targets, and the ratio of Al to Ti is 67:33 (molar ratio); and there is one of each of the other two kinds of targets, wherein the ratio of AlCr is 70:30 (molar ratio); when placed, the AlTi No. 1 target and the AlTiSi target are placed symmetrically. Adjust the basic chamber pressure to 1.0×10 -3 Pa by a vacuum pump, heat the chamber temperature to 550°C and keep it for 30 min, and the rotation speed of the rotating support is 3.5 r / min. First, introduce N2 and Ar in a volume ratio of 1:2, adjust the chamber pressure to 4 Pa, and electrically ionize Ar +The blade substrate was bombarded and cleaned for 15 minutes under a bias voltage of -800 V. The N2 channel was closed, the bias voltage was maintained at -800 V, and the H2 channel was opened (flow rate 30 sccm) to ionize H2 and clean and activate the target material surface for 10 minutes.

[0086] (3) After etching the substrate surface, deposit a TiN transition layer, introduce 200 sccm of N2, maintain the cavity pressure at 4 Pa, maintain the substrate bias voltage of -800 V and the target current of 120 A for 3 min.

[0087] (4) Deposit an AlTiN intermediate layer, increase the cavity pressure to 25 Pa, maintain the target current of 140 A and the substrate bias of -80 V for AlTi target 1 and target 2 for 20 min, and keep other parameters unchanged.

[0088] (5) Deposit AlTiN / AlCrN nanocomposite functional layers, maintaining target currents of 120A, 140A, and 140A for AlCr and AlTi targets and a substrate bias of -90 V for 55 min. Then change the substrate bias to -95 V for 70 min, while keeping other parameters unchanged.

[0089] (6) Deposit the AlCrN surface layer, maintain the AlCr target current of 120 A and the substrate bias voltage of -100 V for 75 min, and keep other parameters unchanged. The final coating thickness is about 1.38 μm.

[0090] Example 7

[0091] (1) Using a carbide blade substrate (model APMT1604), various impurities on the surface are removed by sandblasting. The sandblasting time is 3 s and the pressure is 0.2 MPa. After sandblasting, the substrate is placed in an ultrasonic water tank for acid washing, alkali washing, and ultrapure water washing for 15 s each. After washing, the residual liquid is blown away, and the substrate is dried in a drying oven at 90℃ for 60 min before being sent to the arc ion plating chamber and placed on a rotating support.

[0092] (2) Simultaneously place one each of the following targets: Ti target, AlTi target, AlCr target, and AlTiSi target (all with a purity of 99.9 wt.%). The molar ratio of AlTiAl to Ti is 67:33; the molar ratio of AlTiSi is 60:30:10; and the molar ratio of AlCr is 70:30. The AlTi target and the AlCr target are placed symmetrically. The basic cavity pressure is adjusted to 1.0 × 10⁻⁶ using a vacuum pump. -3Pa, the chamber temperature was heated to 550 ℃ and kept for 30 min, the rotating support speed was 3.5 r / min, N2 and Ar with a volume ratio of 1:2 were first introduced, the chamber pressure was adjusted to 4 Pa, and Ar was arc ionized + , the blade substrate was bombarded and cleaned for 15 min under a bias of -800 V, the N2 channel was closed, the bias was kept at -800 V, the H2 channel (flow rate 30 sccm) was opened to ionize H2 to clean and activate the surface of the target material for 10 min.

[0093] (3) After etching the surface of the substrate, a CrN transition layer was deposited, 200 sccm of N2 was introduced, the chamber pressure was kept at 4 Pa, the substrate bias of the Ti target was kept at -800 V and the target current was 120 A, and the process lasted for 3 min.

[0094] (4) The AlCrN intermediate layer was deposited, the chamber pressure was increased to 25 Pa, the target current of the AlCr target was kept at 120 A, the substrate bias was kept at -80 V, and the process lasted for 20 min, and other parameters remained unchanged.

[0095] (5) The AlTiN / AlCrN intermediate layer was deposited, the target current of the AlCr target and the AlTi No. 1 target was kept at 120 A and 140 A respectively, and the substrate bias was kept at -85 V, and the process lasted for 55 min. Other parameters remained unchanged.

[0096] (6) The AlTiN / AlTiSiN nanocomposite functional layer was deposited, the target current of the AlTi target and the AlTiSi target was kept at 140 A, and the substrate bias was kept at -90 V, and the process lasted for 70 min, then the substrate bias was increased to -100 V and kept for 75 min. Other parameters remained unchanged, and finally the total thickness of the coating was about 1.36 μm.

[0097] The performance of examples 5, 6 and 7 was as follows: after milling 840 m, the average wear of example 5 was 96.4 microns; example 6 was 129.9 microns; and example 7 was 79.9 microns. After milling 1680 m, the average wear of example 5 was 113.5 microns; example 6 was 130.4 microns; and example 7 was 119.1 microns.

Claims

1. A composite coated cutting tool, characterized in that, It includes a cemented carbide substrate and a composite coating on the substrate; the composite coating is prepared by arc ion plating and consists of, from the substrate outward, an XN transition layer, an AlXN intermediate layer deposited on the surface of the XN transition layer, a nanocomposite functional layer deposited on the surface of the AlXN intermediate layer, and an AlXN surface layer deposited on the surface of the nanocomposite functional layer. The nanocomposite functional layer is an AlXN / AlXSiN nanocomposite functional layer; where X is Ti and / or Cr. The composite-coated cutting tool is prepared through the following steps: (1) Argon etching is performed on the surface of the tool substrate, and an XN transition layer is deposited after etching; the etching bias voltage in step (1) is -700~-900 V; The target current for depositing the transition layer is 100~140 A, the bias voltage is maintained at -700~-900 V, and the deposition time is 2~5 min. (2) Perform a first arc ion plating on the surface of step (1) to obtain an AlXN intermediate layer; (3) Perform a second arc ion plating on the surface of step (2) to obtain a nanocomposite functional layer; In step (2), the target current of the first arc ion plating is 120~140 A, the substrate bias voltage is -80~-100 V, and the first arc ion plating time is 15~25 min. The second arc ion plating step (3) is performed in two stages: the first stage has a target current of 120~140 A, a substrate bias voltage of -85~-105 V, and an arc ion plating time of 50~60 min; the second stage has a target current of 120~140 A, a substrate bias voltage of -90 V~-110 V, and an arc ion plating time of 60~80 min. A third arc ion plating is performed on the surface in step (3) to obtain an AlXN surface layer; the target current of the third arc ion plating is 120~140 A, the substrate bias voltage is -100~-120 V, and the third arc ion plating time is 70~80 min.

2. The composite coated cutting tool according to claim 1, characterized in that: The target materials selected are X target, AlX target and AlXSi target, of which there are two AlX targets with a molar ratio of Al to X of 67:33; and one of each of the other two target materials. Alternatively, the target material can be selected as X target or AlX target, with two AlX targets, where the molar ratio of Al to Ti is 67:33 and the molar ratio of Al to Cr is 70:

30. The molar ratio of AlXSi is 60:30:10; AlX target 1 and AlXSi target are placed symmetrically during placement; from etching to arc ion plating 1, 2 and 3 are turned on respectively: X target, AlX target 1 and AlX target 2, AlXSi target and AlX target 1, AlX target 1 and AlX target 2. The purity of the target material used is greater than or equal to 99.9 wt.%.

3. The composite coated cutting tool according to claim 1, characterized in that: Its nitrogen flow rate is 200~500 sccm.

4. The composite coated cutting tool according to claim 1, characterized in that: The overall thickness of the resulting composite coating is 1.60 to 2.0 μm.

5. A composite coated cutting tool according to claim 1, characterized in that: The blade substrates used include one of the following models: APMT1135, APMT1604, RPMT1003, and RDMW1204.

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