Principle of soldering iron welding
It is a science to solder. The idea behind electric soldering iron welding is to use a heated soldering iron to heat and melt solid solder wire, then utilize flux to flow into the metal being welded, and finally, after cooling, make a solid and trustworthy solder bond.
When a copper surface and a tin-lead alloy are used to make a solder, the solder first wets the copper surface. As a result of the wetting, the solder then slowly diffuses to the copper metal, generating an adhesion layer on the contact surface that firmly fuses the two materials. As a result, wetting, diffusion, and metallurgy are the three physical and chemical processes used in soldering.
1. Wetting: Using capillary force, the melted solder runs around along the little bumps and crystalline spaces on the base metal's surface, generating an adhesive layer that allows the base metal and the solder to adhere to one another throughout the welding process. The metal's atoms are in close proximity to one another, getting to the point where their gravitational pull is active.
Conditions in the environment that lead to wetting: The base metal surface that is being welded must be free of impurities and oxides.
Picture metaphor Water cannot moisten the lotus if it is dropped onto its leaves to generate water droplets. If you drop water on cotton, it will seep inside the fibers, allowing the cotton to be moistened.
2. Diffusion: Mutual diffusion between solder and base metal atoms starts to happen as wetting progresses. Once the temperature rises, the atoms in the lattice are typically in a condition of thermal vibration. The base metal and solder atoms cross the contact surface and enter each other's lattice structures due to an increase in atomic activity. The heating temperature and duration determine the atoms' rate of movement and number.
3. Metallurgical combination: An intermediary layer —- metal compound is generated between the two metals as a result of mutual diffusion between the solder and the base metal. A metal compound must form between the base material to be welded and the solder in order to achieve a good solder bond. in order to develop a strong metallurgical connection with the base metal.
