Cold spraying_Introduction to cold air power spraying

       Cold air dynamic spraying technology (CGDS) is a new surface engineering technology developed recently. In the mid-1980s, Russians such as Alkimov discovered this technology by accident, and used this technology to spray-deposit pure metals, alloys and metal-ceramic composite coatings on different substrates. In the 1990s, the patented technology of practical air-conditioning power spraying was obtained, and the first commercial computer-controlled air-conditioning power spraying equipment was launched in 2000.



Cold air power spraying technology is an economical and practical spraying technology, which can be used for the preparation of surface coating of materials to improve and improve the surface properties of materials. Such as: wear resistance, corrosion resistance, electrical conductivity, mechanical properties of materials and other functions, and ultimately achieve the purpose of improving product quality.



The cold air power spraying technology realizes the deposition of the coating at a low temperature. The residual stress formed in the coating is low (mainly compressive stress), and the thickness of the coating can reach several millimeters; the heat-affected zone of the substrate is small, and it has no effect on the spray powder. Thermal influence, no oxidation, no pollution; it can keep the original properties of spray powder materials to the greatest extent, and the properties of the prepared coating basically maintain the properties of the original materials; it provides an important method for the preparation of nanostructured coatings and the nanometerization of metal material surfaces. process method. Compared with the existing coating technology, the spraying efficiency is high, the powder utilization rate is high (the sprayed powder can be recycled), the prepared coating is dense, the porosity is low, the residual stress is low, the heat-affected zone to the base material is small, and high thermal conductivity can be prepared. High conductivity, high conductivity coatings and other functional coatings, with low spray noise. The current research shows that the cold air dynamic spraying technology can realize the coating preparation of AI, Zn, Cu, Ni, Ti, Ag, Co, Fe, Nb, NiCr and other metals and alloys, and can also prepare high melting point Mo, Ta and high hardness coatings. Cermet CrgC2-NiCr, WC-Co and other coatings. Depositable coating materials include most metal coating materials, cermet coating materials, and organic coating materials. It is especially suitable for the preparation of nano-coating materials. It is one of the important process technologies in the field of surface engineering and the best supplement and extension of thermal spraying technology.