Brazing is a joining technique used to join metal parts by utilizing a metal with a lower melting point than the materials being joined. It is technically considered brazing if the metal used melts above 450oC; otherwise, it is soldering. In furnace brazing, the entire assembly is heated to a temperature where the braze alloy melts and flows into the joint. Upon cooling, the alloy solidifies, creating a strong joint.
Almost any metal or ceramic can be brazed as long as the braze alloy effectively wets both surfaces to be joined. Oxide must be removed from metal surfaces to achieve wetting, which is typically done using a flux. In atmospheric pressure processes, hydrogen is often used for oxide reduction, while vacuum brazing relies on the vacuum itself. For ceramics and certain metals, a reactive braze alloy is needed to dissolve or react with the surface for wetting to occur.
The specific method of brazing depends on the materials being joined and the type of furnace used. For example, copper brazed mild steel can be processed in a mesh belt furnace using a copper paste in an endothermically generated atmosphere. In contrast, silver brazed copper can be processed in a vacuum furnace using a copper/silver alloy foil. Another common example is the brazing of aluminum heat exchangers in a mesh belt furnace, where the brazing alloy is roll-bonded onto thin aluminum sheets.
When selecting a braze alloy, the manner of introduction into the joint and its commercial availability should be considered. Ductile metals like copper, silver, and gold base braze alloys are available in various forms such as wire, shim, sheet, and powder. Nickel base braze alloys, on the other hand, are brittle and typically supplied as powder mixed with binders to form a paste. Joint design also influences the preferred form of braze alloy, with pre-placement often necessary for thick joints.
Brazing can be applied to a wide range of materials, including mild steel, stainless steel, cast iron, nickel, aluminum, copper, brass, bronze, ceramics, magnesium, and titanium. Its applications are extensive and include metal housings, electro-mechanical assemblies, pipe fittings, plumbing fixtures, automotive engine components, and HVAC system components.
Compared to welding, brazing has several advantages. It can join dissimilar metals, making it suitable for various applications. Additionally, brazing is well-suited for high-production projects, offers strong joints, and works well with both thick and thin metals.
Overall, brazing is a versatile and effective joining technique for a wide range of metals and ceramics. Its long history and widespread industrial use attest to its reliability and effectiveness in creating strong and durable joints.
Looking for high-quality brazing equipment for joining metals and ceramics? Look no further than KINTEK! Our wide range of brazing solutions is designed to meet your specific application needs. From brass and copper to stainless steel and ceramics, our equipment ensures successful brazing by removing oxide and ensuring wetting. Trust KINTEK for all your brazing requirements. Contact us today!
