Surface Treatment Knowledge Hall: Introduction to thermal spraying
1, Thermal Spray is a kind of surface strengthening technology, which is an important part of surface engineering technology and has always been a new technology project promoted by our country.It is the use of some kind of heat source (such as arc, plasma spray
or combustion flame) Or filiform metallic or non-metallic material to a molten or semi-molten state and then is sprayed onto the surface of the pretreated substrate at a rate by flame holding itself or compressed air to be deposited to form a surface coating having various functions Technology.
2, the principle of thermal spraying: thermal spraying refers to a series of processes, in these processes, fine and dispersed metal or non-metallic coating material, in a molten or semi-molten state, deposited on a prepared substrate surface , To form some sort of spray deposit. The coating material can be in the form of powder, ribbon, filament or rod. Thermal spray guns provide the necessary heat from the fuel gas, arc or plasma arc to heat the thermal spray material to the plastic or molten state and then subject to compressed air acceleration to impinge the constrained particle beam onto the substrate surface. Particles impinging on the surface are deformed by stamping to form laminated sheets that adhere to the surface of the prepared substrate and subsequently cool and accumulate to form a layered coating. The coating due to the different coating materials can achieve high temperature corrosion, abrasion, heat insulation, anti-electromagnetic wave and other functions.
3, the definition: thermal spraying refers to the use of oxygen - acetylene flame, arc, plasma arc, explosion waves provide different heat source spraying device to produce high temperature and high pressure flame flow or supersonic flame flow, the material to be made into a coating such as various Metal, ceramic, metal and ceramic composites, solid spray materials of various plastic powders, instantly heated to a plastic or molten state, sprayed at high speed onto a surface of a pretreated (clean roughed) part forming a coating processing method. We specialize the work surface is called "coating", the manufacturing method of coating is called "thermal spraying", which is a general term for spraying and spraying with various heat sources.
4, use: This under the action of high-speed airflow atomized into fine droplets or high temperature particles, high jet speed jet to the treated workpiece surface, the formation of a solid cover, so that the workpiece surface with different hardness, Wear-resistant, corrosion-resistant, heat-resistant, anti-oxidation, heat insulation, electrical conductivity, sealing, disinfection, anti-microwave radiation and other special physical and chemical properties. It can be repaired in the maintenance of equipment waste, so that scrapped parts "back to life"; also in the manufacture of new products to strengthen and pre-protection, so that "longevity."
5, thermal spray material: spray powder in the entire spray material occupies a very important position. Thermal spraying alloy powder, including nickel-based, iron-based and cobalt-based alloy powder, depending on the coating hardness, respectively, for mechanical parts repair and protection.