All three methods of welding, soldering and brazing are processes of joining two pieces of metal together, as well as filling in gaps in them. However, each type has its own significance and applications. Read on below for the comparison, to understand how each of the methods differs.
In welding, the two metals always have to be the same. You can’t weld two different metals together. For example, copper can’t be welded with steel.
A welding machine uses high temperatures to create molten metal that then joins two metal parts together. Oftentimes, filler metal is also used to create a weld pool that makes the joint even stronger and more durable.
If done correctly, the finished weld will be as strong or stronger as the base metal. However, if the weld was not carried out properly and, for example, the welder applied too much heat, the metal’s properties will be changed, weakening the weld.
There are different types of welding processes, such as MIG, TIG, stick, electron beam and laser welding. There’s also plasma welding, which is a process of cutting through large metal structures by melting through them.
This process is usually used in mechanical industries, such automotive, aerospace, and other.
The brazing process also joins two parts of metal together, but it doesn’t use metal melting for that. Instead, it uses filler metal (alloy), as is sometimes also used in welding. As the pool of molten metal cools, it bonds to the two pieces of metal and thus creating a strong, resilient joint.
The filler needs to be melted at temperatures below that of the metal parts. Unlike welding, brazing can be used to join dissimilar metals. For example, you can braze together copper and aluminum or silver and nickel.
The process also often uses a flux to create a protective atmosphere for the joining metals. It prevents the oxides from forming around the weld pool. It also cleans any contamination that might be left on the brazing surface.
There are also different brazing techniques, such as torch and furnace brazing. Properly brazed joints are stronger than either base metal, but not as strong as welded joints. Brazing does no significant change in base metals.
Brazing applications include automotive and heavy transport industries.
Soldering process is very similar to brazing with the difference only of much lower melting temperature. Soldering also involves the use of fillers or solders. When the melted solder cools down, it solidifies, joining the metal parts together. A successful soldering joint is not as strong as welded or brazed joint.
There are also two different types of soldering processes, which are soft soldering and silver soldering. Each has its own applications.
The same way as in brazing, soldering also uses flux. It cleans the metal surfaces and helps the solder to flow over the parts to be joined.
Originally, lead was used as the filler metal.
Soldering is commonly used in electronics, plumbing, metalwork and jewelry making. When joining electrical components, it doesn’t make the structure strong but connects the parts with conductive solder.
As you’re working with lower temperatures, soldering is considered an easier and safer method to work with. It also requires less of the specialized safety equipment.