Composite film layer for aluminum alloy surface and preparation method thereof

Abstract

The invention relates to the field of vacuum coating, and particularly discloses a composite film layer for an aluminum alloy surface and a preparation method thereof. The composite film layer for the aluminum alloy surface comprises a Cr layer, a CrWC layer, a WC layer and a DLC layer which sequentially cover the aluminum alloy surface. The preparation method comprises the following steps that 1, an alloy is cleaned; 2, ion cleaning is carried out in a vacuum coating chamber; 3, the Cr layer is deposited; 4, the CrWC layer is deposited; 5, the WC layer is deposited; and 6, the DLC layer is deposited. The aluminum alloy covered with the composite film layer is prepared by adopting the preparation method. According to the preparation method, the aluminum alloy can be directly adopted to replace stainless steel to be applied to a 5G signal transmitting tower base station and a mobile phone 3C type appearance decoration part, and the composite film layer has the advantages of being low in cost and good in corrosion resistance, wear resistance, hardness and heat dissipation performance; and in addition, the preparation method has the advantages of being easy to realize industrial production and low in cost.

Description

technical field [0001] The application relates to the field of vacuum coating, more specifically, it relates to a composite film layer used on the surface of aluminum alloy and a preparation method thereof. Background technique [0002] Due to the excellent performance of stainless steel in resistance to weak corrosive media such as air, steam, and water, the method of plating DLC ​​layer on stainless steel is usually used to prepare and apply to 5G signal transmission tower base stations that require high corrosion resistance and wear resistance of materials. As well as raw materials for mobile phone 3C appearance decorations and other fields. However, due to the relatively high cost of stainless steel, aluminum alloys are usually used instead of stainless steel at present. [0003] However, the corrosion resistance and strength of aluminum alloy are not as good as those of stainless steel, and it is difficult to meet the performance requirements of use. Therefore, it is u...

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Problems solved by technology

However, due to the relatively high cost of stainless steel, aluminum alloys are usually used instead of stainless steel

[0003] However, the corrosion resistance and strength of aluminum alloy are not as good as those of stainless steel, and it is difficult to meet the performance requirements of use. Therefore, it is usually necessary to increase the coating thickness of the aluminum alloy surface

[0004] In view of the related technologies mentioned above, the inventor believes that since the film thickness of PVD coating is generally relatively thin, it is difficult to meet the requirements of corrosion resistance. If the film layer of PVD coating is too thick, it is easy to cause excessive stress and appear The problem of peeling off from the base material. Therefore, the current coating method on the aluminum alloy surface is generally a combination of water plating and PVD coating. Generally, a nickel layer or a chromium layer is plated on the surface of the aluminum alloy first, and then a PVD film is coated on the water coating layer. Floor

The deposition rate of the water coating layer is fast, and the thickness can be relatively thick, which can meet the requirements of corrosion resistance, but the water coating layer is prone to bubbles during the deposition process, resulting in poor bonding between the water coating layer and the aluminum alloy surface, which is easy to detachment of film

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