What are the basic processes of thermal spraying

       The basic process of thermal spraying includes: substrate surface pretreatment, spraying, surface heat treatment and coating sealing treatment, and finishing of coating surface.







(1) Substrate surface pretreatment: After the spraying method is selected, the pretreatment process must be selected, including degreasing, rust removal, and surface roughening.







(2) Spraying: During spraying construction, reasonable process parameters must be determined to control the spraying quality.







Including: ① spraying heat source conditions, that is, the type of fuel and the ratio of mixing with oxygen;







②Material conveying, that is, the type, speed, flow rate and conveying position and angle of conveying gas;







③ Spraying materials, including material composition, physical properties, powder shape, particle size, wire or bar diameter, etc.;







④Substrate composition, substrate temperature, performance, and surface treatment method of the machine part; ⑤Spraying operation, including the distance between the spray gun and the machine part, the moving speed of the spray gun or the machine part, the angle between the spray gun and the machine part, and the spraying gas medium, etc.







(3) Post-coating treatment: Sealing treatment or heat treatment should be carried out immediately after coating.







(4) Finishing: After spraying, the coating needs to be ground to ensure dimensional accuracy. In addition, attention must be paid to safety protection during spraying construction.







Including: preventing the hazards of high-speed and high-temperature spraying jets to personnel and equipment; dustproof and ventilation of spraying dust; safety protection of spraying noise and spraying arc radiation.