Introduction
Brazing is a process of joining two objects by using a third, weaker material that remains solid at the joining temperature. The most common brazing procedure is torch-based brazing. This process uses heat to melt the filler metal, which is held in place by capillary action to join the two fabrication components.
Types of Brazing
Brazing can be accomplished through various techniques including gas flame brazing, torch brazing, induction brazing, and furnace brazing. Whatever method chosen must be compatible with the base metal, as well as the temperature.
Gas Flame Brazing
Gas flame brazing is one of the most popular forms of brazing, mainly because it can be done with basic tools and supplies, and still produce good quality results. The process involves heating a torch, which is used to heat the surfaces of the materials being joined. This heat melts the filler metal, which is then allowed to capillarily flow around the entire surface, creating a solid bond.
Torch Brazing
Torch brazing uses a torch or fuel-gas flame to heat the pieces being joined. This flame heats the nearby surfaces, melts the filler metal, and allows it to capillarily flow over the entire surface, creating a strong bond. While this process is relatively simple and relatively safe, it is also dependent on the operator’s skill and experience. Inexperienced operators may create weak bonds, or may create excessive heat damage to the materials being jointed.
Induction Brazing
Induction brazing is a form of brazing that is slightly different from torch brazing in that the heating elements are placed inside the joint, rather than externally applied. The heating elements, usually coils, create an electrical induction field, which generates heat within the joint in order to either melt the filler metal or create a very hot field. The filler metal is then allowed to flow into the joint as it is slowly heated. The advantage of induction brazing is that the heat is localized, meaning that the filler metal is only melted within the joint and not in the surrounding areas.
Furnace Brazing
Furnace brazing is similar to induction brazing, but instead of using electrical induction fields, it uses heat from a furnace to melt the filler metal. The main advantage of furnace brazing is that it can join larger parts than can be heated with less powerful methods, such as torch or induction brazing. However, the downside of this is that it takes longer, as well as potentially costing more.
Conclusion
Brazing is a great way to join two metals together, forming a strong and lasting bond. There are several methods that can be used to accomplish this, each requiring different skills and each requiring the right type of material to use as a filler. The most popular brazing methods are torch brazing, gas flame brazing, induction brazing, and furnace brazing, each with their own advantages and disadvantages. Regardless of the method chosen, brazing is often used in fabrication and manufacturing, and can be applied in various industries.
