Brazing is a modern technique for creating durable, long-lasting metal joints. The process fuses metal parts together by melting a different metal (with a lower melting point than the base metals) to create a seamless bond. Capillary action draws the filler metal through the joint and forms an even seal. Metals that are fused are not melted or altered in any way, retaining specific properties that are crucial to the overall product. Brazing can be used to assemble a diverse array of products, from tank blades for the defense industry, to cover plates for land-based turbines, to controlled parts for aircraft engines and pneumatic tools for the construction industry.

A product that is greater than its parts
Brazing brings versatility to the production process by giving manufacturers a wide choice in filler metals and alloys. These filler metals and alloys can be specifically chosen to add strength, durability or other enhanced qualities to the finished product. In essence, brazing creates a metal joint that is stronger and performs better than the metal parts that form it. Brazing also creates a smooth, even appearance in the joint that contributes to a product’s marketability and minimizes the costly need for finishing once the process is complete. Brazing is an excellent choice for joining ferrous metals such as stainless steel with non-ferrous metals such as copper. It is also effective for bonding metals that resist welding.

Atmosphere versus Vacuum
Quality performs brazing services in either an atmosphere or vacuum environment.

When appropriate, Quality Steel Treating eliminates the challenge of metal oxidation by brazing in a vacuum—meaning no air, oxygen or other gases are present when the treatment occurs. Vacuum brazing is an effective way to clean parts (i.e. vaporizing fingerprints) and is most useful when the product contains refractory or reactive metals. It is also best for working with certain exotic and nickel-based alloys containing:
• Aluminum
• Molybdenum
• Niobioum
• Zirconium
• Tantalum
• Titanium

QST’s atmosphere brazing services use argon, a naturally-occurring inert gas that serves as a protective environment for the metals being joined. It is an excellent choice for working with air-sensitive metals and protects them from oxidation with high-vapor pressure elements (such as zinc, cadmium and lead) that cannot be joined safely through vacuum brazing. Atmosphere brazing also minimizes any need for post-braze cleaning.

factors in brazing