Welding and Metal Joining

Welding and metal joining are essential processes that allow two or more metal pieces to be permanently joined. These methods rely on the application of heat, pressure, or both, to fuse the metals or to use a filler material to connect them. Over the years, these techniques have evolved from simple forging to high-tech processes. 

Unlike welding, brazing and soldering use a filler material with a lower melting point than that of the base metals. These processes do not melt the base pieces, making them ideal for joining metals with different melting points or for preventing part deformation. 

• Brazing: This uses a filler material, such as a copper or silver alloy, that melts above 450 °C. The molten filler flows by capillarity into the gap between the pieces and solidifies, creating a strong joint. Brazing is used to join pipes, air conditioning components, and bicycle parts. 

• Soldering: Similar to brazing, but uses filler materials, such as lead-tin solder, that melt below 450 °C. Soldered joints are less resistant than brazed joints but are ideal for electronics and plumbing, as the low heat protects sensitive components. 

Although welding and brazing are traditional methods, metal adhesion with structural adhesives has gained ground in industries such as aerospace and automotive. These polymer adhesives, such as epoxies, can join metals and other materials, distributing the load more uniformly and eliminating the need for heat, which prevents part deformation.

Each of these techniques offers unique advantages in terms of strength, aesthetics, and efficiency, allowing engineers to choose the ideal joining method for each project.