Advanced devices increasingly need ceramic and metal in the same assembly — an insulating ceramic body sealed into a metal housing, an electrical feedthrough, a sensor window. Joining the two is notoriously difficult: adhesives outgas and age, mechanical seals leak, and conventional braze alloys simply will not wet a ceramic surface. Active metal brazing (AMB) solves the problem at the metallurgical level, forming a true chemical bond between ceramic and metal in a single furnace cycle.
Why Active Metal Brazing?
The traditional route to a ceramic-to-metal joint requires metallizing the ceramic first — a multi-step process of its own — before a conventional braze will take. Active braze alloys eliminate that step: they incorporate a reactive element, typically titanium, that chemically reacts with the ceramic surface at brazing temperature and wets it directly. We run the process in high vacuum with staged binder removal, precisely controlled soak profiles, and managed cooling rates to relieve the thermal-expansion mismatch between ceramic and metal — producing clean, flux-free, hermetic joints.
Benefits
- True metallurgical bond between ceramic and metal — not an adhesive or mechanical seal
- Hermetic, vacuum-tight joints
- Single-cycle process — no separate ceramic metallization step
- Flux-free, high-vacuum processing leaves no corrosive residues
- Joint strength and temperature capability far beyond polymer alternatives
- Well suited to miniature, precision components
Materials
Active metal brazing joins alumina and other technical ceramics — including zirconia, aluminum nitride, and sapphire — to stainless steels and other engineering alloys. Alumina to 316L stainless steel is a demonstrated combination in our lab.
Applications
- Hermetic sensor and electronics packages for medical devices
- Ceramic electrical feedthroughs and insulators
- Diagnostic and analytical instrument assemblies
- Vacuum and pressure hardware
- Optical and sapphire window assemblies
- Harsh-environment and high-temperature sensors