CN-122013092-A - Al2O3NiAl double-layer coating and preparation method thereof

Abstract

The invention discloses an Al 2 O 3 -NiAl double-layer coating and a preparation method thereof, belonging to the technical field of metal material plating. The invention provides an Al 2 O 3 -NiAl double-layer coating on the surface of an aluminum alloy and a preparation method thereof, aiming at solving the problem of limited service performance of the surface of the aluminum alloy in the prior art, wherein the Al 2 O 3 -NiAl double-layer coating is formed by spraying a NiAl coating on an aluminum alloy substrate, mixing nickel powder and aluminum powder through the NiAl coating, then spraying and reacting to obtain a coating containing NiAl and Ni 3 Al compounds, and oxidizing the NiAl coating to form a compact Al 2 O 3 ceramic layer on the surface. The Al 2 O 3 -NiAl double-layer coating has a compact structure, can effectively prevent corrosive media from penetrating and crack from expanding, and has good corrosion resistance and wear resistance.

Inventors

• ZHANG XIAOLIN
• DING YI
• LI MINGLIANG
• QIAN HAO
• GAO XUEFEI
• LI KEQIANG
• TANG HUADONG
• FENG FAN
• WANG FEI

Assignees

• 中航成飞民用飞机有限责任公司

Dates

Publication Date

20260512

Application Date

20260415

Claims (10)

1. The preparation method of the Al 2 O 3 -NiAl double-layer coating is characterized by comprising the following steps: A. Performing sand blasting treatment on the surface of the aluminum alloy matrix to obtain an aluminum alloy substrate with roughened surface; B. mechanically mixing metal nickel powder and metal aluminum powder according to a molar ratio of 3:1-3, and spraying the nickel aluminum mixed powder on the surface of the aluminum alloy substrate with roughened surface by adopting plasma spraying to obtain a metal NiAl coating, wherein in the step B, the thickness of the obtained metal NiAl coating is 100-300 mu m; C. And C, oxidizing the aluminum alloy substrate plated with the metal NiAl coating at 400-550 ℃ in an air atmosphere to obtain an Al 2 O 3 -NiAl double-layer coating, wherein the thickness ratio of the Al 2 O 3 coating to the NiAl coating in the obtained Al 2 O 3 -NiAl double-layer coating is 0.1-0.6:1.
2. 2. The preparation method of the Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step B, the particle size of the aluminum powder is 45-100 μm.
3. 3. The preparation method of the Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step B, the plasma spraying condition is that the voltage is 50-60V, the current is 400-450A, the flow rates of main gas Ar and auxiliary gas H 2 are respectively 60-70L/min and 2-3L/min, the flow rate of powder feeding gas Ar is 5-7L/min, the spraying distance is 90-110 mm, and the travelling speed is 8-10 cm/s.
4. 4. The method for preparing an Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step C, the thickness ratio of the Al 2 O 3 coating to the NiAl coating in the obtained Al 2 O 3 -NiAl double-layer coating is 0.4-0.55:1.
5. 5. The method for preparing the Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step C, the oxidation time is 2-6 hours.
6. 6. The method for preparing the Al 2 O 3 -NiAl double-layer coating according to claim 4, wherein in the step C, the oxidation time is 5-6 hours.
7. 7. The method of claim 1, wherein in step A, the aluminum alloy substrate is 7075 aluminum alloy, 7055 aluminum alloy, 6061 aluminum alloy or 2024 aluminum alloy.
8. 8. The method for preparing the Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step A, the time of the sand blasting treatment is 5-10 min.
9. 9. The method for preparing the Al 2 O 3 -NiAl double-layer coating according to claim 1, wherein in the step B, the particle size of the nickel powder is 45-150 μm.
10. 10. The Al 2 O 3 -NiAl double-layer coating prepared by the preparation method of the Al 2 O 3 -NiAl double-layer coating according to any one of claims 1-9.

Description

Al 2O3 -NiAl double-layer coating and preparation method thereof Technical Field The invention belongs to the technical field of metal material plating, and particularly relates to an Al 2O3 -NiAl double-layer coating and a preparation method thereof. Background The aluminum alloy has been widely used in various fields such as construction, aerospace and automobile manufacturing due to its advantages of light weight, high strength and good workability. However, aluminum alloys also present the problem of being susceptible to corrosion and wear, which not only affects their appearance, but also reduces their performance and service life, even in certain critical areas (e.g., aerospace) where safety may be compromised. The surface coating may provide protection for aluminum alloy components in service environments. Aiming at the problems, a great deal of researches on protective coatings on the surfaces of aluminum alloys are carried out at home and abroad. CN 110760782A discloses a wear-resistant aluminum alloy, which comprises an aluminum alloy substrate and a wear-resistant coating plated on the surface of the aluminum alloy substrate, wherein the wear-resistant coating comprises an Al/Ni primer layer plated on the aluminum alloy substrate and a metal ceramic composite coating plated on the Al/Ni primer layer, the Al/Ni primer layer comprises, by mass, 2-8% of Al, the balance of Ni, and the metal ceramic composite coating comprises, by mass, 10-30% of WC and the balance of Ni60. CN113089048a discloses an application of a protective coating for a welded joint, wherein the protective coating for the welded joint has a double-layer structure of an anodic aluminum oxide layer and a Ni-P plating layer, and the protective coating for the welded joint is applied to a welded joint surface of aluminum alloy friction stir welding, and the preparation method comprises the following steps of 1) pretreating the welded joint surface of aluminum alloy to obtain a smooth and smooth welded joint surface of aluminum alloy to be reinforced, 2) performing anodic oxidation treatment on the welded joint surface of aluminum alloy to be reinforced obtained through the treatment in step 1) to obtain a compact porous anodic aluminum oxide intermediate layer, 3) performing activation reaming treatment on the anodic aluminum oxide intermediate layer obtained through the treatment in step 2) to obtain the welded joint surface of nickel-aluminum alloy to be plated, and 4) performing electrochemical nickel plating treatment on the welded joint surface of nickel-aluminum alloy to be plated obtained through the treatment in step 3) to obtain the protective coating for the welded joint. CN118835243A discloses a preparation method of an aluminum alloy micro-arc oxidation-chemical plating Ni/P electromagnetic shielding coating, which comprises the following steps of 1 grinding and cleaning an aluminum alloy sample, 2 preparing a micro-arc oxidation coating by adopting a double-pulse direct current power supply, 3 immersing the micro-arc oxidation sample obtained in the step 2 into a sensitization solution for 1-5 min, flushing residual liquid with deionized water, 4 activating the sample in an activation solution for 20-50 s, flushing the residual liquid with deionized water, 5 reducing the sample in a reduction solution for 10-90 s, taking out, flushing the residual liquid with deionized water, 6 performing chemical plating treatment in a water bath, 7 immersing the workpiece obtained in the step 6 in a stearic acid ethanol solution, wherein the concentration of the stearic acid ethanol solution is 0.1-1 mol/L, the solution temperature is 50-70 ℃, the soaking time is 1-8 h, and taking out and drying to obtain the composite coating. CN118308715A discloses a preparation method of a pitting corrosion resistant aluminum-based composite coating, which comprises the following steps of S1, mechanically mixing aluminum alloy powder, branched-crystal Ni powder, cr powder and spherical Al 2O3 powder according to the mass ratio of 9-21:3-7:12-28:10, drying in 50-80 ℃ blasting dryness to prepare mixed powder, S2, carrying out sand blasting treatment on a metal substrate under the pressure of 0.5-0.8 MPa by adopting silicon carbide sand grains to enable the surface roughness Sa of the metal substrate to reach 2.5, S3, putting the mixed powder into low-pressure cold spraying equipment, adjusting the parameters of the low-pressure cold spraying equipment, wherein the pressure of a spray gun is 0.6-0.85 MPa, the working temperature is 400-600 ℃, the moving speed of a nozzle is 800-1200 mm/min, the powder supply speed is 0.5-0.9 g/s, and carrying out spraying on the surface of the metal substrate subjected to sand blasting pretreatment by operating machines to obtain the pitting corrosion resistant aluminum-based composite coating. It can be seen that the surface service performance of the Al 2O3 layer is improved by anodic oxidation or micro-arc oxidation