Thermal Spray Overview

       1. Thermal spraying is a surface strengthening technology and an important part of surface engineering technology. It has always been a new technology project promoted in my country. It uses a certain heat source (such as arc, plasma spraying or combustion flame, etc.) to heat powder or filamentary metal or non-metallic materials to a molten or semi-molten state, and then sprays them at a certain speed with the help of the flame itself or compressed air. A technique in which a pretreated substrate surface is deposited to form a surface coating with various functions.



  2. Principle of thermal spraying: Thermal spraying refers to a series of processes in which fine and dispersed metallic or non-metallic coating materials are deposited on the surface of a prepared substrate in a molten or semi-molten state to form Some kind of spray deposited layer. The coating material can be powder, ribbon, wire or rod. The thermal spray gun provides the necessary heat by fuel gas, electric arc or plasma arc, heats the thermal spray material to a plastic or molten state, and then is accelerated by compressed air, so that the confined particle beam impinges on the surface of the substrate. Particles that hit the surface are deformed by stamping to form a laminated sheet, which adheres to the surface of the prepared substrate, then cools and accumulates to form a layered coating. The coating can achieve high temperature corrosion resistance, wear resistance, heat insulation, electromagnetic wave resistance and other functions due to different coating materials.



3. Definition: Thermal spraying is a metal surface processing method that sprays molten sprayed materials on the surface of parts through high-speed airflow to form a sprayed layer. We call the special working surface "coating" and the working method of making the coating "thermal spraying", which is a general term for spraying and spray welding using various heat sources.



4. Uses: Under the action of high-speed airflow, it is atomized into fine molten droplets or high-temperature particles, which are sprayed to the surface of the treated workpiece at a high flying speed to form a firm covering layer, so that the surface of the workpiece can obtain different hardness and wear resistance. , Corrosion resistance, heat resistance, oxidation resistance, heat insulation, insulation, electrical conductivity, sealing, disinfection, microwave radiation resistance and various other special physical and chemical properties. It can repair the old and make good use of waste in equipment maintenance, so that the scrapped parts can be "revived"; it can also be strengthened and pre-protected in the manufacture of new products to "prolong life".



5. Thermal spray material: Spray powder occupies a very important position in the entire thermal spray material. Thermal spray alloy powders include nickel-based, iron-based and cobalt-based alloy powders, which are used in the repair and protection of mechanical parts according to different coating hardness.