Thermal spraying technology
Thermal spraying technology is defined in the national standard GB / t18719-2002 "thermal spraying terms and classification": thermal spraying technology is a method of using heat source to heat spraying materials to molten or semi molten state, and spray deposition on the surface of pretreated substrate at a certain speed to form coating. Thermal spraying technology makes a special working surface on the surface of common materials to achieve a series of functions, such as anti-corrosion, wear resistance, friction reduction, high temperature resistance, oxidation resistance, heat insulation, insulation, conductivity, microwave radiation protection, etc., so as to achieve the purpose of saving materials and energy. We call the special working surface coating and the working method of coating as thermal spraying 。 Thermal spraying technology is an important part of surface process technology, accounting for about one third of surface engineering technology.
Advantages of thermal spraying technology
1. The equipment is light and can be used on site.
2. The process is flexible and the operation procedure is few. It can repair quickly and reduce processing time.
3. Strong adaptability, generally not limited by the size of the workpiece and the site.
4. The coating thickness can be controlled.
5. In addition to spray welding, the heating temperature of the substrate is lower, the deformation of the workpiece is small, and the change of crystal structure and properties is also small.
6. It is suitable for parts of various matrix materials and can be used to prepare various protective coatings and functional coatings on almost all solid materials.
Characteristics of thermal spraying technology
From the analysis of the principle and process of thermal spraying technology, thermal spraying technology has the following characteristics
1. Due to the wide temperature range of the heat source, the coating materials that can be sprayed include almost all solid engineering materials, such as metals, alloys, ceramics, cermets, plastics and their composites. Therefore, the surface that can give the substrate various functions (such as wear resistance, corrosion resistance, high temperature resistance, oxidation resistance, insulation, heat insulation, biocompatibility, infrared absorption, etc.) can be applied
2. In the process of spraying, the heat on the surface of the substrate is small and can be controlled, so it can be sprayed on various materials (such as metal, ceramics, glass, cloth, paper, plastic, etc.), and has little effect on the structure and properties of the substrate, and the deformation of the workpiece is small
3. The equipment is simple and the operation is flexible. It can not only spray the large-scale components in large area, but also spray in the designated parts; it can be sprayed in the factory room or in the outdoor field.
With the improvement of the application requirements and the expansion of the field of thermal spraying, especially the progress of spraying technology itself, such as the increasingly high-energy and excellent spraying equipment, and the gradual increase of coating material varieties, the spraying operation procedures are less, the construction time is shorter, the efficiency is higher, and the economy is relatively economical, With the gradual improvement of performance, thermal spraying technology has obtained rapid development in recent ten years, not only the application field has been greatly expanded, but also the technology has developed from the early preparation of general protective coating to the preparation of various functional coatings; from the maintenance of single workpiece to the production of a large number of products; from single coating preparation to product failure analysis, surface pretreatment, coating materials It has become a very active subject in the field of material surface science and gradually formed in modern industry The independent material processing technology such as casting, forging, welding and heat treatment has become an important technological means to save valuable materials, save energy, improve product quality, prolong the service life of products, reduce costs and improve work efficiency. It has been widely used in various fields of national economy