The Two Different Processes of Brazed and Weld

When you are working with metal and need to join two pieces together to attain a different shape or length you can use one of two processes to do this – braze and weld. You can also choose one of these to fix a length of metal that is broken or to fill in a few pieces to strengthen the piece.

What is braze?

In order to braze metals, you must use an alloy and there are several that you can use – silver, aluminum, copper and nickel. If you are familiar with soldering, then you will be able to braze easily. It is extremely important to clean the base metals thoroughly and the clearance between them. This is because in this process you do not heat the base metals, but you do heat and melt the alloys. Both the alloy and the metals must be oxide free and when putting them together you have to ensure that there is a tight fit. When you apply them properly, you will be assured of having a stronger connection.

What is weld?

Welding is the process of joining two metals together for a specific reason. This process involves the use of very high temperatures to join the filler and the base metal. In order to produce the high heat needed for welding, you need to use an electric arc, friction and gasoline. It is different from brazing in that while the filler is melted so is the base metal in order for the two to completely bond.

How are brazing and welding different?

Although both brazing and welding are two important processes used in the construction and fabrication industries and both of them require the use of heat, there are main differences between the two. In the brazing method, you only heat the alloy to the melting point and then applied to the base metals that you want to join. It will flow between the two of them making a connection. When you weld two pieces of metal together you have to melt the connecting alloy as well as the ends of both of the base pieces. In this way they are melted together to form a strong bond. While both processes require the use of heat, brazing does not need to have the high temperature that welding does.

It really doesn’t matter which process you use to join the metals as long as you take care to do it properly in order to have the strength and shape that you need. By not doing it properly, the joints will not hold and will need to be redone and this could be a costly mistake.

Summary

  1. You do not have to use the same high temperatures in brazing as you do in welding.
  2. When you weld two metals together, you have to melt the filler and the two metals. This changes the properties of the base metal.
  3. When you use brazing to join two metals, you don’t need to melt the metals – only the filler needs to be heated and melted.

 

  • The Expert

    Brazing is a metal-joining
    process whereby a filler metal is heated above and distributed between two or
    more close-fitting parts by capillary action. The filler metal is brought
    slightly above its melting temperature while protected by a suitable
    atmosphere, usually a flux. It then flows over the base metal and is then
    cooled to join the work pieces together.

     

    Welding is a fabrication
    or sculptural process that joins materials, usually metals or thermoplastics, by
    causing coalescence. This is often done by melting the work pieces and adding a
    filler material to form a pool of molten material that cools to become a strong
    joint, with pressure sometimes used in conjunction with heat, or by itself, to
    produce the weld. This is in contrast with soldering and brazing, which involve
    melting a lower-melting-point material between the work pieces to form a bond
    between them, without melting the work pieces.
     

    metal fabrication