Important uses of electroplating equipment and electroplating technology in the aviation field
1 Common surface treatment technology for aerospace equipment materials Common process methods for surface treatment of aerospace equipment materials include: anodizing, micro-arc oxidation, electroplating, thermal spraying, vapor deposition, high-energy beam processing, sol-gel method, etc. The fundamental task of these processing technologies is to form a new surface through surface treatment technology, thereby giving the surface materials of spacecraft new functional characteristics.
1.1 Anodizing Anodizing is most widely used in aluminum and aluminum alloy materials. Aluminum and its alloys are placed in electrolytes such as sulfuric acid, chromic acid, and oxalic acid as anodes, and electrolyzed under specific conditions and external current to form an oxide film on their surface. This oxide film changes the surface state and properties of the aluminum alloy, and can play a role in surface coloring, improving corrosion resistance, enhancing wear resistance and hardness, and protecting the surface of aluminum parts. Sulfuric acid DC anodizing process is the most commonly used anodizing technology. After sulfuric acid DC anodizing, the surface hardness of aluminum parts increases, and the wear resistance and corrosion resistance are enhanced. The thin layer of anodized film has a large number of micropores, which can absorb various lubricants and is suitable for manufacturing cylinders or other wear-resistant parts of spacecraft power systems; the film has strong micropore adsorption capacity and can be colored into various beautiful and bright colors.
1.2 Micro-arc oxidation Micro-arc oxidation technology, also known as plasma oxidation technology, refers to the surface treatment technology of in-situ growth of ceramic oxide films on the surface of non-ferrous metals such as Al, Mg, Ti, Nb, Zr and their alloys using plasma chemistry and electrochemistry principles. This technology breaks through many shortcomings of traditional anodizing. By controlling the process, the metal surface is ceramicized, and the resulting ceramic film has excellent wear and corrosion resistance, high hardness and insulation resistance. Compared with other similar technologies, the comprehensive performance of the film layer has been greatly improved, and the process is simple, easy to operate, and has high processing efficiency. Therefore, it has been increasingly applied and developed in the field of aerospace.
1.3 Electroplating Electroplating treatment can form a uniform coating on the surface of complex structure devices, so it has been widely used in the field of surface protection of aerospace equipment materials. In precision electronic devices, electroplating of Au, Ag and other metals can obtain highly reliable electrical contacts and graphic coatings; electroplating of tungsten alloy layers enables the surface of spacecraft in harsh service environments to withstand high-temperature burning and radiation thermal corrosion above 2,000 °C; electroplating technology can also prepare coatings that give the surface of aerospace equipment special functions such as magnetism or electromagnetic shielding.
1.4 Thermal Spraying Thermal spraying technology is a method of using a heat source to heat the spraying material to a molten or semi-molten state, and spraying and depositing it at a certain speed onto the surface of a pretreated substrate to form a coating, giving the substrate surface some special properties. Thermal spraying technology is widely used and can prepare functional coatings such as corrosion resistance, electrical insulation, wear resistance and friction reduction, high temperature oxidation resistance, and electromagnetic shielding absorption. Spray coating materials can be metals, metal alloys, ceramics, metal ceramics, plastics, and composite materials, etc., and are widely used in various parts of aerospace equipment.
