TWI426153B - Coated article and method for making the same - Google Patents

Description

Coating member and preparation method thereof

The invention relates to a coating material and a preparation method of the coating material.

Aluminum alloys and magnesium alloys have the advantages of light weight, good heat dissipation and the like, and are widely used in the fields of automobile, aviation, communication, electronics, machinery and the like. However, due to the high chemical activity of aluminum and magnesium, it is easily oxidized in the air to form an oxide film. Under normal atmospheric conditions, the oxide film on the surface of aluminum and magnesium can effectively protect the aluminum or magnesium matrix, but in the electrolyte containing In moisture, such as the atmospheric environment of the ocean surface, severe corrosion will occur on the surface of aluminum and magnesium alloys, which will seriously damage the appearance of the product and shorten the service life of the product.

Salt spray resistance is an important parameter for the corrosion resistance of aluminum alloys and magnesium alloys. In order to improve the salt spray resistance of aluminum and magnesium alloys, surface treatment of aluminum and magnesium alloys is usually required. Common treatment methods There are anodizing treatment, baking varnish, etc., but these processes have large environmental pollution problems. The vacuum coating (PVD) technology is a very environmentally friendly coating process, and the coating film can be rich in variety and excellent in wear resistance. However, the film deposited by PVD process tends to grow in the form of columnar crystal, so the film layer exists. A large amount of intercrystalline gaps result in insufficient film densification and cannot effectively prevent salt spray erosion.

In view of this, it is necessary to provide a coated member which can effectively improve the salt spray resistance of aluminum and magnesium alloys.

In addition, it is also necessary to provide a method of preparing the above-mentioned coated member.

A coated member comprising a substrate and an anticorrosive layer formed on the surface of the substrate, the anticorrosive layer containing zirconium tungstate and aluminum oxynitride.

A method for preparing a coated member, comprising the steps of: providing a substrate; forming an anti-corrosion layer on the surface of the substrate by magnetron sputtering, the anti-corrosion layer containing zirconium tungstate and aluminum oxynitride, and using an aluminum-based target The aluminum-based target contains metal aluminum and zirconium tungstate, and nitrogen and oxygen are used as reaction gases.

The coating member of the invention deposits an anti-corrosion layer on the surface of the substrate, the anti-corrosion layer contains zirconium tungstate and aluminum oxynitride, and the zirconium tungstate has a negative thermal expansion coefficient, and the zirconium tungstate can be decreased with the temperature after the coating is completed. The expansion fills the gap between the aluminum oxynitride particles, so that the anti-corrosion layer reaches a more dense structure, which can effectively delay the penetration of the salt spray on the substrate and improve the corrosion resistance of the substrate.

10‧‧‧coated parts

11‧‧‧ base

13‧‧‧Anti-corrosion layer

20‧‧‧Vacuum Coating Machine

21‧‧‧ coating room

23‧‧‧Aluminum-based target

25‧‧‧Track

30‧‧‧vacuum pump

1 is a cross-sectional view of a coated member according to a preferred embodiment of the present invention; and FIG. 2 is a schematic view of a vacuum coater according to a preferred embodiment of the present invention.

Referring to FIG. 1, a coated member 10 according to a preferred embodiment of the present invention includes a substrate 11 and an anti-corrosion layer 13 formed on the surface of the substrate 11. The anti-corrosion layer 13 contains aluminum oxynitride (AlON) and zirconium tungstate (ZrW). ₂ O ₈ ), wherein the zirconium tungstate has a mass percentage of 15 to 35%.

The material of the base 11 is pure aluminum, aluminum alloy, pure magnesium or magnesium alloy.

The anti-corrosion layer 13 can be formed by magnetron sputtering. The anticorrosive layer 13 has a thickness of 0.5 to 1.1 μm.

ZrW ₂ O ₈ has a negative thermal expansion coefficient, that is, has the property of "heat shrinking and cold expansion", so that the gap between the aluminum oxynitride particles can be filled during the cooling after sputtering, so that the anticorrosive layer 13 reaches a dense structure. .

A method of preparing a coated member 10 according to a preferred embodiment of the present invention includes the following steps:

(a) A substrate 11 is provided which is pure aluminum, an aluminum alloy, a pure magnesium or a magnesium alloy.

(b) The substrate 11 is pretreated. The pretreatment includes grinding, electropolishing, wiping the surface of the substrate 11 with deionized water and absolute ethanol, and ultrasonic cleaning in acetone.

(c) Referring to FIG. 2, a vacuum coater 20 is provided. The vacuum coater 20 includes a coating chamber 21 and a vacuum pump 30 connected to the coating chamber 21 for vacuuming the coating chamber 21. In the coating chamber 21, a turret (not shown), a two-aluminum-based target 23 and a baffle (not shown) are provided. The baffle is used to sputter the sputtered particles onto the substrate 11 when the target is cleaned, which is automatically turned on or off by electric control. The turret drives the base 11 to revolve along a circular trajectory 25, and the base 11 also rotates as it revolves along the trajectory 25.

The aluminum-based target 23 contains metal aluminum and zirconium tungstate, wherein the zirconium tungstate has a mass percentage of 20 to 40%, and the balance is metal aluminum. The aluminum-based target 23 is prepared by a conventional powder metallurgy method, and the zirconium titanate powder with a mass percentage of 20-40% and the balance aluminum powder are uniformly mixed, and the cold isostatic pressing is used to form a blank body. After 800~880 °C sintering for 2~5h, it is naturally cooled. The aluminum-based target 23 prepared above may be sanded with a sandpaper to make the surface of the target flat.

(d) cleaning the aluminum-based target 23, the specific operation is: opening the baffle, vacuuming the coating chamber 21 to 3.0×10-5Pa, opening the aluminum-based target 23, and adjusting the bias of the substrate 11 to −50~ -150 V, then an argon gas (purity of 99.999%) having a flow rate of 500 sccm (standard state ml/min) was introduced into the coating chamber 21, and the surface of the aluminum-based target 23 was bombarded with argon gas, and sputtered for 10 minutes to make the target surface Impurities and dirt are spattered onto the baffle.

(e) An anti-corrosion layer 13 is sputtered on the substrate 11 by magnetron sputtering. As shown in FIG. 2, the base 11 is fixed on the rotating frame of the coating chamber 21 of the vacuum coating machine 20, and the coating chamber 21 is heated to a temperature of 100 to 120 ° C; the two aluminum-based target 23 is opened, and an aluminum-based target is disposed. The power of 23 is 6~8kw, the bias voltage applied to the base 11 is set to be -50~-150V; the working gas argon gas is introduced, the flow rate of argon gas is 100~300sccm, the reaction gas nitrogen and oxygen are introduced, and the flow rate of nitrogen is 10~20sccm, oxygen flow rate is 10~20sccm, coating time is 30~120min. The anticorrosive layer 13 has a thickness of 0.5 to 1.1 μm.

After the coating is completed, the coated member 10 is taken out by vacuum and allowed to cool naturally.

It can be understood that the coating member 10 can also provide a primer layer of aluminum or magnesium between the substrate 11 and the anti-corrosion layer 13 to increase the adhesion between the film layer and the substrate.

The invention will now be specifically described by way of examples.

Example 1

The vacuum coating machine 20 used in this embodiment is an intermediate frequency magnetron sputtering coating machine, which is produced by Shenzhen Nanfang Innovation Vacuum Technology Co., Ltd., model SM-1100H.

The material of the base 11 used in the present embodiment is an aluminum alloy.

Preparation of aluminum-based target 23: 25% by mass of zirconium tungstate powder and the balance of aluminum powder were uniformly mixed, and formed into a blank by cold isostatic pressing, and then naturally cooled after sintering at 810 ° C for 3.5 hours.

Sputtering anti-corrosion layer 13: aluminum-based target 23 has a power of 6 kW, an oxygen flow rate of 15 sccm, a nitrogen gas flow rate of 15 sccm, an argon gas flow rate of 250 sccm, a bias voltage of -100 V, a coating temperature of 100 ° C, and a coating time of 60min.

Example 2

The vacuum coater 20 used in the present embodiment is the same as that in the first embodiment.

The material of the base 11 used in the present embodiment is a magnesium alloy.

Preparation of aluminum-based target 23: 30% by mass of zirconium tungstate powder and the balance of aluminum powder were uniformly mixed, cold isostatic pressing to make a blank, and then sintered at 880 ° C for 3.5 h and then naturally cooled.

Sputtering anti-corrosion layer 13: the power of the aluminum-based target 23 is 7kw, the flow rate of oxygen is 20sccm, the flow rate of nitrogen is 15sccm, the flow rate of argon gas is 250sccm, the bias voltage is -100V, the coating temperature is 100 ° C, and the coating time is 75min.

Comparative example

The aluminum alloy substrate was sputtered by the same intermediate frequency magnetron sputtering coater as in Example 1, and the aluminum target was used as the target. The aluminum target power was 8 kw, the reaction gas was nitrogen and oxygen, and the nitrogen flow rate was 80 sccm. At 20 sccm, the bias voltage applied to the aluminum alloy substrate was -200 V, the duty ratio was 50%, and the sputtering time was 40 min, and a one-component aluminum oxynitride (AlON) layer was sputtered on the surface of the aluminum alloy substrate.

A sample of the coated aluminum oxide (AlON) film prepared by the coating member 10 prepared by the method of the present invention and the comparative example was subjected to a 35 ° C neutral salt spray (NaCl concentration of 5%). As a result, it was found that the samples prepared in the comparative examples were significantly corroded after 72 hours; and the coated members 10 prepared by the methods of Examples 1 and 2 of the present invention all showed corrosion after 120 hours.

The coating member 10 of the present invention deposits an anti-corrosion layer 13 on the surface of the aluminum or magnesium substrate 11, the anti-corrosion layer 13 containing zirconium tungstate and aluminum oxynitride, and the zirconium tungstate has a negative thermal expansion coefficient, and the coating is completed When the temperature is lowered, the zirconium tungstate can expand to fill the gap between the aluminum oxynitride particles, so that the anti-corrosion layer 13 can reach a more dense structure, can effectively delay the penetration of the salt spray on the substrate 11, and improve the corrosion resistance of the substrate 11. .

10‧‧‧coated parts

11‧‧‧ base

13‧‧‧Anti-corrosion layer

Claims (9)

A coating member comprising a substrate and an anti-corrosion layer formed on the surface of the substrate, wherein the anti-corrosion layer contains zirconium tungstate and aluminum oxynitride, and the zirconium tungstate in the anti-corrosion layer fills between the aluminum oxynitride particles Void. The coated member according to claim 1, wherein the substrate is made of pure aluminum, aluminum alloy, pure magnesium or magnesium alloy. The coated article according to claim 1, wherein the anti-corrosion layer is formed by magnetron sputtering and has a thickness of 0.5 to 1.1 μm. The coated article according to claim 1, wherein the anti-corrosion layer has a mass percentage of zirconium tungstate of 15 to 35%. A method for preparing a coated member, comprising the steps of: providing a substrate; forming an anti-corrosion layer on the surface of the substrate by magnetron sputtering, the anti-corrosion layer containing zirconium tungstate and aluminum oxynitride, and using an aluminum-based target The aluminum-based target contains metal aluminum and zirconium tungstate, and nitrogen and oxygen are used as reaction gases, and the zirconium tungstate in the anti-corrosion layer fills the gap between the aluminum oxynitride particles. The method for preparing a coated member according to claim 5, wherein the substrate is pure aluminum, an aluminum alloy, a pure magnesium or a magnesium alloy. The method for preparing a coated member according to claim 5, wherein the aluminum-based target has a mass percentage of zirconium tungstate of 20 to 40%, and the balance is metal aluminum. The method for preparing a coated member according to claim 5, wherein the aluminum-based target is prepared by a powder metallurgy method, and the tungstic acid is 20-40% by mass. The zirconium powder and the balance aluminum powder are uniformly mixed, and a solid body is formed by cold isostatic pressing, and then naturally cooled by sintering at 800 to 880 ° C for 2 to 5 hours. The method for preparing a coated member according to claim 5, wherein the specific process parameters of the step of forming the anti-corrosion layer are: the power of the aluminum-based target is 6-8 kw, and the bias voltage of the substrate is -50~ -150V, argon gas as working gas, argon gas flow rate is 100~300sccm, nitrogen and oxygen as reaction gases, nitrogen flow rate is 10~20sccm, oxygen flow rate is 10~20sccm, coating temperature is 100~120°C, coating The time is 30~120min.