Which surface treatment technologies can be applied to fasteners in the aerospace field?

Here are some surface treatment technologies applicable to fasteners in the aerospace field:

1.Passivation Treatment:

Through specific chemical or electrochemical treatments, a dense oxide or chemical film, known as a passivation film, is formed on the metal surface. This film effectively isolates the metal from direct contact with the external environment, thereby reducing the risk of chemical or electrochemical corrosion. It is suitable for various metal materials such as stainless steel, aluminum alloys, and titanium alloys.

2.Aluminum Plating:

Aluminum coatings can weaken or even eliminate contact corrosion between fasteners and connectors, while also providing a certain degree of lubrication during assembly, reducing friction between threaded pairs and the shank and the mounting holes of connectors.

3.Ion Vapor Deposition (IVD) Aluminum Plating:

This is a method of forming an aluminum coating on the surface of titanium alloy fasteners. It has good protective and lubricating properties, improving the corrosion resistance and service life of the fasteners.

4.Silver Plating:

The patent application from Xi’an Zhitong Aviation Technology Co., Ltd., titled “A Method for Silver Plating the Surface of Aviation Fasteners,” features a simple, convenient, efficient, and environmentally friendly process. The resulting silver plating layer exhibits good adhesion to the fastener, excellent anti-discoloration capabilities, high gloss, and good film density.

5.Molybdenum Disulfide Dry Film Lubrication:

Molybdenum disulfide possesses low friction coefficient, high temperature resistance, and heavy pressure resistance. It can form a strong, heat-resistant, and heavy-pressure-resistant molybdenum disulfide lubricating protective film on the friction surfaces of metal parts, preventing wear, burning, and seizing. It is commonly used for lubrication and protection of aerospace fasteners.

6.Aluminum Alloy Anodizing:

Aluminum alloy fasteners can be anodized to generate a porous alumina film. Sealing the pores improves corrosion resistance and also achieves a better appearance.

7.Ferrous Metal Oxidation (Blackening):

For aerospace fasteners made of ferrous metals, blackening treatment can be performed to form a magnetite film, improving rust resistance, but with relatively poor wear resistance.