Flux is a chemical mixture that is usually based on rosin and is an auxiliary material that ensures the smooth progress of the welding process. It plays an important role in the welding process. What is its specific role? The following is the knowledge of the role and harm of flux prepared by Xiaobian for everyone. Let's learn together!
First, the role of flux
The main contributing ingredient in the flux is rosin. The rosin is decomposed by tin at around 260 degrees Celsius, so the tin bath temperature should not be too high. Flux is a chemical that promotes welding. In solder, it is an indispensable auxiliary material and its role is extremely important.
(1) Dissolution of the oxide film on the surface of the base material to be welded
In the atmosphere, the surface of the base material being welded is always covered with an oxide film, and its thickness is approximately 2×10-9 to 2×10-8m. In the welding, the oxide film will inevitably hinder the wetting of the base metal by the solder, and the welding cannot be performed normally. Therefore, it is necessary to apply a flux on the surface of the base material so as to reduce the oxide on the surface of the base material, thereby eliminating the oxide film. .
(2) Prevent reoxidation of the base material being welded
The base metal needs to be heated during the welding process. At high temperatures, the metal surface will accelerate oxidation. Therefore, the liquid flux covers the surface of the base metal and the solder to prevent them from oxidizing.
(3) Reducing the surface tension of molten solder
The surface of the molten solder has a certain tension, just as the rain falls on the lotus leaf. The surface tension of the liquid will immediately coalesce into bead-like droplets. The surface tension of the molten solder will prevent it from flowing to the surface of the base metal, affecting the normal progress of wetting. When the flux covers the surface of the molten solder, the surface tension of the liquid solder can be reduced, and the wetting performance is significantly improved.
(4) Protection of the surface of the welding base material The original surface protection layer of the material to be welded has been destroyed during welding. After the soldering is finished, the good solder flux quickly recovers the effect of protecting the welding consumables.
Second, the hazard of flux
The flux that is completely harmless to the human body does not exist. Of course, this hazard exists only during the moment when the flux is used as a chemical reaction.
Fluxes that are less harmful to the human body are there, and that is environmental flux. The higher the environmental protection requirements, the less harmful the flux will be to the human body. However, there is no flux that is completely harmless to the human body because the flux itself is a chemical product.
Of course, the higher the requirement for environmental protection, the higher the flux cost and the higher the flux price. Therefore, many factories only purchase fluxes that just meet customer requirements in order to save costs.
Third, the poor flux residue and countermeasures
Flux residue causes problems that have a certain degree of corrosivity to the substrate, reduce the conductivity, and cause migration or short circuit. Non-conductive solids such as intrusion into the contact parts of the components can cause poor bonding, excessive resin residues, and adhesion of dust and debris. , affect the use of product reliability.
Reasons for use and countermeasures: Select appropriate flux, moderate activator activity, use flux to form a protective film after soldering, use no flux residue after soldering, use low solids no-clean flux, post-weld cleaning .
Xiao Bian concludes: The relevant knowledge on the role of flux and flux hazards is introduced here, and I hope to help everyone. If you want to know more related information, you can pay attention to this website information.
Environmental protection testing environmental protection latex paint brand reinforced laminate flooring environmental protection green wardrobe brand green putty powder
Manual Sausage Filler,Sausage Filler Machine,Home Sausage Stuffer,Commercial Sausage Filler
Suzhou CoreMission International Trading Co.,Ltd. , https://www.szcoremission.com