Workpiece surface modification layer and method of making same

Abstract

The application discloses a workpiece surface modification layer and a preparation method thereof. The method comprises the following steps: S100, Cr metal is injected on the surface of a workpiece to be modified by using an ion injection technology to form an injection layer; S200, after the step S100, a CrAl film layer is deposited on the surface of the workpiece to be modified by using a technology combining ion injection and magnetron sputtering to form a composite metal transition layer; S300, after the step S200, a CrAlN film layer and a Cr film layer are deposited on the surface of the workpiece to be modified by using a magnetic filter cathode vacuum CrAl arc source and a Cr arc source to form a functional protective layer. The modification layer prepared by using the preparation method of the workpiece surface modification layer has strong adhesion with the surface of the workpiece, the film layer is uniform, the modification layer with corrosion resistance and wear resistance can be effectively prevented from falling off, and the service life of the workpiece is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of surface modification by physical vapor deposition, in particular to a method for preparing a modified layer on the surface of a workpiece such as an aviation hydraulic tank, and is suitable for preparing a modified layer on the inner wall surface of a workpiece made of aluminum alloy material and the like, which is resistant to corrosion and wear. BACKGROUND

[0002] During the working process of workpieces such as aviation hydraulic tanks and gears, the inner wall surface or the external surface thereof moves repeatedly to generate friction and wear, and the wear debris generated by wear can further aggravate wear. When used in harsh natural environments including sand, moisture, and marine environments, the surface of the workpiece has certain mold growth and corrosion phenomena, thereby causing the contact surface between the inner wall of the aviation hydraulic tank and the piston to fail, the meshing of the gear surface to fail, and the like. The failure of the contact surface between the inner wall of the hydraulic tank causes the hydraulic pump to fail to work normally, thereby causing the aircraft to lose control, and the failure of the meshing of the gear surface causes the gears to fail to work normally, thereby causing the gears to fail to work normally, which have serious consequences. Therefore, it is necessary to perform corrosion-resistant and wear-resistant protective treatment on the inner wall of the hydraulic tank, the surface of the gear, and the like to reduce the risk. At present, the commonly used method for modifying the surface of the workpiece is the hard chromium plating method, but this method not only pollutes the environment, but also has a low product qualification rate and cannot meet the requirements. Therefore, it is urgent to use an environmentally friendly and pollution-free technology to prepare a modified layer with excellent corrosion resistance and wear resistance. SUMMARY

[0003] The present application aims to provide a method for preparing a modified layer on the surface of a workpiece, which has excellent corrosion resistance and wear resistance and is not easy to fall off. Another object of the present application is to provide a modified layer on the surface of a workpiece prepared by the above method.

[0004] In order to achieve the above-mentioned objects, the method for preparing a modified layer on the surface of a workpiece comprises the following steps:

[0005] S100, using ion implantation technology to implant Cr metal on the surface of a workpiece to be modified to form an implanted layer;

[0006] S200, after the step S100, using ion implantation and magnetron sputtering combined technology to deposit a CrAl film layer on the surface of the workpiece to be modified to form a composite metal transition layer;

[0007] S300, after the step S200, using a magnetic filter cathode vacuum CrAl arc source and a Cr arc source to deposit a CrAlN film layer and a Cr film layer on the surface of the workpiece to be modified to form a functional protective layer.

[0008] In an embodiment of the above-mentioned method for preparing a modified layer on the surface of a workpiece, the step S300 comprises:

[0009] S310, depositing a CrAlN film layer on the surface of the workpiece to be modified by using a magnetic filter cathode vacuum CrAl arc source;

[0010] S320, after the step S310, depositing a Cr film layer and a CrAlN film layer on the surface of the workpiece to be modified by using a magnetic filter cathode vacuum Cr arc source and a CrAl arc source, wherein the Cr film layer and the CrAlN film layer are alternately formed for multiple times.

[0011] In an embodiment of the method for preparing the workpiece surface modification layer, in the step S100, the vacuum degree reaches 1.0×10 -3 Pa, the ion source voltage is 45KV, the extracted beam current is 5mA, and the implantation dose is 1-3×10 17 cm 3 .

[0012] In an embodiment of the method for preparing the workpiece surface modification layer, in the step S200, the arc current is 60-70A, the deposition negative bias is controlled to be 300-500V, the duty cycle is maintained to be 70-90%, the ion source voltage is 35-50KV, the extracted beam current is 5mA, and the deposition time is 5-10 minutes.

[0013] In an embodiment of the method for preparing the workpiece surface modification layer, in the step S310, the nitrogen flow is controlled to be 50-70sccm, the arc current is 60-70A, the vacuum degree of the vacuum chamber is maintained to be 1.0×10 -2 -2.0×10 -2 Pa, the deposition negative bias is controlled to be 300-500V, the duty cycle is maintained to be 70-90%, and the deposition time is 5-10 minutes.

[0014] In an embodiment of the method for preparing the workpiece surface modification layer, in the step S320, when forming the CrAlN film layer of each layer, the nitrogen flow is controlled to be 50-70sccm, the arc current is 60-70A, the vacuum degree of the vacuum chamber is maintained to be 1.0×10 -2 -2.0×10 -2 Pa, the deposition negative bias is controlled to be 100-300V, the duty cycle is maintained to be 70-90%, and the deposition time is 10-20 minutes.

[0015] The workpiece surface modification layer of the present application comprises a workpiece surface and a modification layer formed on the workpiece surface, wherein the modification layer is prepared by the method for preparing the workpiece surface modification layer, and the modification layer comprises an implantation layer, a composite metal transition layer and a functional protection layer which are sequentially formed on the workpiece surface.

[0016] In an embodiment of the workpiece surface modification layer, the functional protection layer comprises:

[0017] The first functional protective layer comprises a first CrAlN film layer and is formed on the composite metal transition layer.

[0018] The second functional protective layer is formed on the first functional protective layer and comprises Cr film layers and second CrAlN film layers arranged alternately in layers.

[0019] In an embodiment of the workpiece surface modification layer, the thickness of the injection layer is 50-70 nm, the thickness of the composite metal transition layer is 50-200 nm, and the thickness of the functional protective layer is 2100-5300 nm.

[0020] In an embodiment of the workpiece surface modification layer, the thickness of the first CrAlN film layer in the functional protective layer is 100-300 nm, the thickness of each Cr film layer is 100-300 nm, and the thickness of each second CrAlN film layer is 300-500 nm.

[0021] The workpiece surface modification layer prepared by the preparation method has strong adhesion to the workpiece surface, uniform film layer, can effectively prevent the modification layer from falling off, and improves the service life of the workpiece.

[0022] The application will be described in detail below in combination with the drawings and specific embodiments, but is not limited to the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a partial sectional view of the workpiece surface modification layer of the application.

[0024] Figure 2 It is a flowchart of the preparation method of the workpiece surface modification layer of the application.

[0025] Figure 3 It is a photo of the 96-hour salt spray corrosion resistance of the surface modification of the aviation hydraulic oil tank prepared by the preparation method of the application.

[0026] In the drawings, reference numerals

[0027] 410: inner wall

[0028] 420: modification layer

[0029] 421: injection layer

[0030] 422: composite metal transition layer

[0031] 423: functional protective layer

[0032] 4231: first functional protective layer

[0033] 4232: second functional protective layer DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings and specific examples, so as to further understand the purposes, solutions and effects of the present application, but not as a limitation on the protection scope of the appended claims of the present application.

[0035] The preparation method of the workpiece surface modification layer of the present application is suitable for various workpieces with corrosion resistance and wear resistance requirements, such as aviation hydraulic oil tank, gear, etc. The preparation method of the present application adopts ion implantation and magnetic filter cathode vacuum arc discharge technology combined with ion beam assisted deposition technology to deposit a metal transition layer on the surface of the workpiece, and adopts magnetic filter cathode vacuum arc discharge technology to deposit a metal / ceramic multilayer composite film layer. The corrosion-resistant and wear-resistant modification layer prepared on the inner wall or outer surface of the workpiece by the preparation method of the present application has strong adhesion to the workpiece, the film layer is uniform, and the problem of peeling off of the corrosion-resistant and wear-resistant modification layer can be effectively solved, the adhesion between the modification layer and the substrate is increased, and the service life is improved. The following takes the aviation hydraulic oil tank made of 2A70 aluminum alloy material as an example for illustration.

[0036] In detail, in combination with Figure 1 and Figure 2 , the preparation method of the workpiece surface modification layer of the present application comprises the following steps:

[0037] S100, using ion implantation technology, implanting Cr metal on the surface of the workpiece to be modified to form an implanted layer;

[0038] S200, after the step S100, using ion implantation and magnetron sputtering combined technology, depositing a CrAl film layer on the surface of the workpiece to be modified to form a composite metal transition layer;

[0039] S300, after the step S200, using a magnetic filter cathode vacuum CrAl arc source and a Cr arc source to deposit a CrAlN film layer and a Cr film layer on the surface of the workpiece to be modified to form a functional protective layer.

[0040] That is, the above steps S100, S200 and S300 are sequentially performed to sequentially form an implanted layer, a composite metal transition layer and a functional protective layer on the surface of the workpiece to be modified.

[0041] Further, the step S300 comprises:

[0042] S310, using a magnetic filter cathode vacuum CrAl arc source to deposit a CrAlN film layer on the surface of the workpiece to be modified;

[0043] S320, after the step S310, depositing Cr film layer and CrAlN film layer on the surface of the workpiece to be modified by using magnetic filter cathode vacuum Cr arc source and CrAl arc source, wherein the Cr film layer and the CrAlN film layer are alternately formed for multiple times.

[0044] In the step S310, the deposition negative bias when depositing the CrAlN film layer is higher than the deposition negative bias when depositing the CrAlN film layer in the step S320, and the deposition time when depositing the CrAlN film layer in the step S310 is lower than the deposition time when depositing the CrAlN film layer in the step S320, so that the CrAlN film layer formed in the step S310 is thinner. The CrAlN film layer deposited in the step S310 can improve the adhesion of the film layer.

[0045] According to the above method, the CrAlN film layer is deposited on the surface of the workpiece to be modified by using the magnetic filter cathode vacuum Cr arc source and the CrAl arc source, and the Cr film layer and the CrAlN film layer are alternately formed for multiple times. Figure 1 The aviation hydraulic oil tank of the present application comprises an inner wall 410 and a modified layer 420 formed on the inner wall, wherein the modified layer 420 comprises an injection layer 421, a composite metal transition layer 422 and a functional protective layer 423 formed on the inner wall 410 in sequence, i.e. the injection layer 421 is first formed on the inner wall 410, the composite metal transition layer 422 is formed on the injection layer 421, and the functional protective layer 423 is formed on the composite metal transition layer 422.

[0046] The protective coating of the prepared aviation hydraulic oil tank is a hard coating. Generally, the material of the aviation hydraulic oil tank is aluminum, which has low hardness. The purpose of the injection layer 421 of the modified layer 420 is to improve the hardness of the surface of the substrate, i.e. to improve the hardness of the surface of the inner wall 410 of the aviation hydraulic oil tank, so as to reduce the difference between the hardness of the surface layer of the substrate and the hardness of the deposited coating, and to reduce the internal stress between the coating and the substrate. After injecting Cr, the composition of the surface of the material forms a CrAl alloy, which is consistent with the element composition of the composite metal transition layer 422 deposited later, so as to further improve the adhesion between the coating and the substrate. The main function of the composite metal transition layer 422 is to improve the adhesion of the coating. The function of the functional protective layer 423 is to improve the wear resistance and corrosion resistance of the workpiece.

[0047] The functional protective layer 423 comprises a first functional protective layer 4231 and a second functional protective layer 4232, the first functional protective layer 4231 comprises a first CrAlN film layer, the first CrAlN film layer is formed on the composite metal transition layer 422, the second functional protective layer 4232 is formed on the first functional protective layer 4231, and the second functional protective layer 4232 comprises a Cr film layer and a second CrAlN film layer stacked and arranged alternately, wherein the thickness of the first CrAlN film layer of the first functional protective layer 4231 is less than the thickness of the second CrAlN film layer of the second functional protective layer 4232.

[0048] The thickness of the injection layer 421 is 50-70 nm, the thickness of the composite metal transition layer 422 is 50-200 nm, and the thickness of the functional protective layer 423 is 2100-5300 nm.

[0049] In the functional protective layer 423, the thickness of the first CrAlN film layer of the first functional protective layer 4231 is 100-300 nm, the thickness of the Cr film layer of each layer of the second functional protective layer 4232 is 100-300 nm, and the thickness of the second CrAlN film layer of each layer is 300-500 nm.

[0050] The bonding force of the modified layer 420 on the inner wall of the aviation hydraulic oil tank is above 80 N, and under the same working condition, the corrosion resistance of the modified workpiece is improved by more than 2 times, and the wear resistance is improved by more than 2 times.

[0051] In step S100 of the preparation method of the workpiece surface modification layer, the vacuum degree reaches 1.0x10 -3 Pa, the ion source voltage is 45KV, the extracted beam current is 5mA, and the injection dose is 1-3x10 17 cm 3 ; in step S200, the arc current is 60-70A, the deposition negative bias is controlled at 300-500V, the duty cycle is maintained at 70-90%, the ion source voltage is 35-50KV, the extracted beam current is 5mA, and the deposition time is 5-10 minutes.

[0052] In step S310 of the preparation method of the workpiece surface modification layer, the nitrogen flow is controlled at 50-70sccm, the arc current is 60-70A, the vacuum degree of the vacuum chamber is maintained at 1.0x10 -2 -2.0x10 -2 Pa, the deposition negative bias is controlled at 300-500V, the duty cycle is maintained at 70-90%, and the deposition time is 5-10 minutes; in step S320, when forming each layer of CrAlN film layer, the nitrogen flow is controlled at 50-70sccm, the arc current is 60-70A, the vacuum degree of the vacuum chamber is maintained at 1.0x10 -2 -2.0x10 -2 Pa, the deposition negative bias is controlled at 100-300V, the duty cycle is maintained at 70-90%, and the deposition time is 10-20 minutes. In step S320, for example, 5-10 times are repeated to make the Cr film layer and the CrAlN film layer alternate 5-10 times.

[0053] As shown in the embodiment, the Cr film layer and the CrAlN film layer of the modified layer 420 are alternately stacked 6 times. Figure 1 In combination Figure 3 , the specific parameters of the modified layer 420 prepared in this embodiment are as follows:

[0054] 1. Corrosion resistance: after 96 hours of salt spray test, the sample surface prepared with film has no corrosion pits or corrosion products.

[0055] 2. Wear resistance: the wear resistance is improved by at least 3 times compared with before plating.

[0056] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims attached to the present application.

Claims

1. A method for producing a surface modification layer of a workpiece, characterized by, The method comprises the following steps: S100, injecting Cr metal on the surface of the workpiece to be modified to form an injection layer by using ion implantation technology; S200, after the step S100, depositing a CrAl film layer on the surface of the workpiece to be modified to form a composite metal transition layer by using ion implantation and magnetron sputtering combined technology, so as to improve the adhesion of the coating; S300, after the step S200, depositing a CrAlN film layer and a Cr film layer on the surface of the workpiece to be modified to form a functional protective layer by using a magnetic filter cathode vacuum CrAl arc source and a Cr arc source, so as to improve the wear resistance and corrosion resistance of the workpiece; The step S300 comprises: S310, depositing a CrAlN film layer on the surface of the workpiece to be modified by using a magnetic filter cathode vacuum CrAl arc source; S320, after the step S310, depositing a Cr film layer and a CrAlN film layer on the surface of the workpiece to be modified by using a magnetic filter cathode vacuum Cr arc source and a CrAl arc source, wherein the Cr film layer and the CrAlN film layer are alternately formed for multiple times; The deposition negative bias when depositing the CrAlN film layer in the step S310 is higher than the deposition negative bias when depositing the CrAlN film layer in the step S320, and the deposition time when depositing the CrAlN film layer in the step S310 is lower than the deposition time when depositing the CrAlN film layer in the step S320, so that the CrAlN film layer formed in the step S310 is thinner than the CrAlN film layer formed in the step S320, so as to improve the adhesion of the film layer.

2. The method of claim 1, wherein The vacuum degree reaches 1.0×10 -3 The ion source voltage is 45 KV, the extraction beam current is 5 mA, and the injection dose is 1-3×10 17 / cm 3 .

3. The method of claim 1, wherein In the step S200, the arc current is 60-70 A, the deposition negative bias is controlled to be 300-500 V, the duty cycle is maintained to be 70-90%, the ion source voltage is 35-50 KV, the extracted beam current is 5 mA, and the deposition time is 5-10 minutes.

4. The method of claim 1, wherein In the step S310, the nitrogen flow is controlled to be 50-70 sccm, the arc current is 60-70 A, the vacuum degree of the vacuum chamber is maintained at 1.0x10 -2 -2.0x10 - 2 Pa, the deposition negative bias is controlled to be 300-500 V, the duty cycle is maintained to be 70-90%, and the deposition time is 5-10 minutes.

5. The method of claim 1, wherein In the step S320, when forming the CrAlN film layer of each layer, the nitrogen flow is controlled to be 50-70 sccm, the arc current is 60-70 A, the vacuum degree of the vacuum chamber is maintained at 1.0×10 -2 -2.0×10 -2 Pa, the deposition negative bias is controlled to be 100-300 V, the duty cycle is maintained to be 70-90%, and the deposition time is 10-20 minutes.

6. A workpiece surface modification layer comprising a workpiece surface and a modification layer formed on the workpiece surface, characterized by, The modification layer is made by the method for preparing a workpiece surface modification layer according to any one of claims 1 to 5, and the modification layer comprises an injection layer, a composite metal transition layer and a functional protective layer which are sequentially formed on the surface of the workpiece; The functional protective layer comprises: a first functional protective layer comprising a first CrAlN film layer, which is formed on the composite metal transition layer; a second functional protective layer comprising a Cr film layer and a second CrAlN film layer which are alternately stacked, and which is formed on the first functional protective layer, wherein the thickness of the first CrAlN film layer is less than the thickness of the second CrAlN film layer.

7. The workpiece surface-modified layer of claim 6, wherein, The thickness of the injection layer is 50-70 nm, the thickness of the composite metal transition layer is 50-200 nm, and the thickness of the functional protective layer is 2100-5300 nm.

8. The workpiece surface-modified layer of claim 7, wherein, In the functional protective layer, the thickness of the first CrAlN film layer is 100-300 nm, the thickness of each Cr film layer is 100-300 nm, and the thickness of each second CrAlN film layer is 300-500 nm.

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