Brazing is a metal-joining technique wherein a filler metal is used to join two or more materials by drawing it into the joint by capillary action. A filler metal is a material with a melting point lower than that of the materials to be joined. Brazing exhibits several benefits over other metal-joining processes, especially welding:
- Base metals never melt, thus enabling close tolerances and joining materials neatly without going for secondary finishing
- Homogenous heating of components reduces thermal distortion when compared to welding
- Suitable for cost-efficient joining of complex and multi-part assemblies as brazing can easily join non-metals and dissimilar metals
Vacuum brazing is performed in a specially designed furnace in the absence of air and delivers the following benefits:
- Extremely clean
- Flux-free braze joints with high integrity and superior strength
- Improved temperature uniformity
- Lower residual stresses owing to slow heating and cooling cycle, resulting in dramatically improved mechanical and thermal properties of the material
- Age hardening or heat treating of the work piece is part of the metal-joining process, but all in a single furnace cycle
Vacuum brazing is convenient for mass production, like traditional brazing. It is used in many different industries, including automotive, aerospace, medical, and much more.
Conditions for High-Quality Brazing
For high-quality brazed joints, it is necessary to closely fit the parts to be joined and clean the base metals to make them free of oxides through chemical or mechanical (abrasive) cleaning.
It necessary to maintain proper surface roughness during mechanical cleaning because the capillary action of the filler material takes place more readily on a rough surface when compared to a smooth surface.
Time and temperature also play a key role in the quality of brazed joints. The filler metal’s alloying and wetting action increases with the rise in the temperature of the braze alloy. Typically, the brazing temperature chosen must be higher than the melting point of the filler metal, although there are several other parameters to be considered in temperature selection.
In general, the braze temperature is kept as low as possible in order to reduce heat effects on the assembly, minimize filler metal/base metal interactions, and optimize the life of fixtures. Most production braze processes are designed to reduce brazing time and related costs.
TITAN H6 Vacuum Furnace
The TITAN H6 vacuum furnace from Ipsen is a pure-bred brazing machine, specially engineered for delivering optimal brazing performance.
It has 6,000-pound gross load capacity with a work zone volume of 36" x 36" x 48". The entire line of TITAN furnaces was designed utilizing a sophisticated flow-production process, which uses premium components.
The following are the technical features of TITAN that emphasize the rigorous prerequisites of brazing:
- Super-charged pumping system that can easily handle extreme vapor loads of brazing
- Robust CFC-lined hot zone, resistant to braze material run-off
- Improved controls delivering high part-temperature uniformity
- Capable of fulfilling Nadcap and AMS 2750D/2750E applicable requirements
The TITAN H6 can be utilized as a vacuum brazing furnace for a myriad of processes:
- Copper joining
- Nickel joining
- Ceramic to metal
- Radiators and oil coolers
Besides providing long-lasting equipment and robust processing capabilities, Ipsen-quality workmanship ensures quick delivery, installation and start-up and offers customized solutions based on the requirement of customers.
Ipsen, Inc., a top manufacturer of vacuum and atmosphere furnaces, is the leader in thermal processing technology.
From vacuum furnace systems to their world-class Aftermarket Support team – Ipsen delivers quality.
This information has been sourced, reviewed and adapted from materials provided by Ipsen.
For more information on this source, please visit Ipsen.