Explanation

Also called soldering flux, the flux used in soldering. brazing flux is used in soldering to ensure smooth soldering process and secure soldering joints. brazing flux is widely used in most soldering, except for soldering in vacuum and protective atmosphere or using ft brazing flux brazing filler metal. The functions of brazing flux in soldering process mainly include: removing the surface oxides of base metal and brazing filler metal - creating necessary conditions for the wetting and spreading of liquid brazing filler metal on the surface of soldering base metal; The surface of soldering base metal and brazing filler metal is covered with a liquid film layer. Prevent oxidation during the heating process; activation or conditioning the surface, improve the wetting and flow of brazing filler metal. For this reason. brazing flux must meet the following basic requirements: it has sufficient ability to remove the oxide film on the surface of base metal and brazing filler metal; The melting temperature and minimum active temperature of brazing flux are lower than the melting temperature of brazing filler metal: it has sufficient thermal stability in the soldering temperature range; Low viscosity and good flow ability at soldering temperature; It can well wet the base metal and brazing filler metal; The density is less than that of liquid brazing filler metal. The brazing flux used in soft soldering is called soft brazing flux, which can be divided into organic soft brazing flux and inorganic soft brazing flux. The organic soft brazing flux is mainly used in the electronic industry. Including rosin, esters, amines, organic halides, etc., with weak corrosiveness; Inorganic soft agents mainly include hydrochloric acid, hydrofluoric acid, phosphoric acid, zinc chloride, ammonium chloride, etc., which have strong corrosiveness. The brazing flux used in brazing is called brazing flux, which mainly includes borax, boric acid, fluoride and chloride of alkali metals and alkaline earth metals.

Classification