Here are some surface treatment techniques that can be applied to fasteners in the aerospace field:

Passivation treatment: By specific chemical or electrochemical treatment, a dense oxide film or chemical film is formed on the metal surface, known as a passivation film. This film can effectively isolate metals from direct contact with the external environment, thereby reducing the risk of chemical or electrochemical corrosion of metals. It is suitable for various metal materials such as stainless steel, aluminum alloys, titanium alloys, etc.

Aluminum plating treatment: Aluminum coating can weaken or even eliminate the contact corrosion between fasteners and connectors, while providing a certain lubrication effect for fasteners during assembly to reduce the friction between threaded pairs and the mounting holes between the rod and the connector.

Ion vapor deposition (IVD) aluminum plating: It is a method of forming an aluminum coating on the surface of titanium alloy fasteners, which has good protective and lubricating properties, and can improve the corrosion resistance and service life of fasteners.

Silver plating treatment 4: Xi'an Zhitong Aviation Technology Co., Ltd. has applied for a patent for "a method of silver plating on the surface of aviation fasteners". The process is simple, easy to operate, efficient, and environmentally friendly. The obtained silver plating layer has good adhesion to the fasteners, good anti discoloration ability, high glossiness, and good coating density.

Molybdenum disulfide dry film lubrication: Molybdenum disulfide has low friction coefficient, high temperature resistance, and heavy pressure resistance. It can form a strong, heat-resistant, and heavy pressure resistant molybdenum disulfide lubrication protective film on the friction surface of metal parts, avoiding component wear, ablation, and biting. It is commonly used for lubrication and protection of aerospace fasteners.

Aluminum alloy anodizing: Aluminum alloy fasteners can be treated with anodizing to generate a porous aluminum oxide film. Sealing treatment can improve corrosion resistance and also achieve good appearance effects.

Black metal oxidation (blackening): For aerospace fasteners made of black metal materials, blackening treatment can be performed to form a layer of iron oxide film, which enhances rust prevention ability, but the wear resistance is relatively poor.