Brazing with Ipsen's Titan Type-6 Vacuum Furnace

Brazing is a metal joining process in which two or more materials are joined when a filler metal (having a melting point lower than that of the materials themselves) is drawn into the joint between them by capillary action.

Brazing has many advantages over other metal-joining techniques, particularly welding. Since the base metals never melt, brazing allows much tighter control over tolerances and produces a cleaner connection, normally without the need for secondary finishing. Because components are heated uniformly, brazing results in less thermal distortion than welding, and brazing provides the ability to easily join dissimilar metals and non-metals. Also note that brazing is ideally suited to cost-effective joining of complex and multi-part assemblies.

Vacuum brazing is carried out in the absence of air, using a specialized furnace and delivers significant advantages: extremely clean, flux-free braze joints of high integrity and superior strength. Improved temperature uniformity when heating in a vacuum, and lower residual stresses due to slow heating and cooling cycle results in significantly improved thermal and mechanical properties of the material. Other benefits of vacuum brazing include heat-treating or age-hardening of the work piece as part of the metal-joining process, all in a single furnace cycle. Like conventional brazing, vacuum brazing is easily adapted to mass production.

In order to obtain high-quality brazed joints, parts must be closely fitted and the base metals must be clean and free of oxides, normally accomplished by either chemical cleaning or mechanical (abrasive) cleaning. In the case of mechanical cleaning, proper surface roughness must be maintained as the capillary action of the filler material occurs much more readily on a rough surface than a smooth surface.

Temperature and time are also important factors that contribute to the quality of brazed joints. As the temperature of the braze alloy is increased, the alloying and wetting action of the filler metal increases as well. In general, the brazing temperature selected must be above the melting point of the filler metal, though there are several other factors that influence the joint designer's temperature selection. Typically, the preferred process will have the lowest possible braze temperature to minimize heat effects on the assembly, keep filler metal/base metal interactions to a minimum and maximize the life of fixtures. Most production braze processes are optimized to minimize brazing time and the associated costs.

The New Ipsen TITAN Type-6 Vacuum Furnace is a pure-bred brazing machine specifically designed for optimal brazing performance. With a work zone volume of 36"x 36"x48" and incredible 6,000 lb gross load capacity, there is nothing comparable on the market today. The entire TITAN family of furnaces was engineered from the start as a global production tool that switches easily between 20+ different languages, and metric or imperial units. The Titan will also operate on any standard voltage from 220 V to 460 V and frequencies of either 50 Hz or 60 Hz. It fits in one standard shipping container or on one standard semi trailer AND can be installed in about a day.

A sample of TITAN's technical features focused on the rigorous needs of brazing:

• Super-charged pumping system easily handles extreme vapor loads of brazing
• Ipsen certified for aerospace
• Enhanced controls delivering high part temperature uniformity
• Rugged CFC-lined hot zone resistant to braze material run-off

The TITAN Type-6 can be used for many different brazing processes including nickel joining, copper joining, ceramic to metal, radiators and oil coolers. Industries that often use this processing technology are medical, aerospace and automotive along with numerous others.