Hydrogen furnace brazing is a precision brazing process performed in a controlled hydrogen atmosphere to reduce surface oxides and create a high-strength braze joint. Furthermore, clean and bright surfaces free of oxidation and contaminants make hydrogen-brazed assemblies ready for further assembly immediately (without additional operations or processing). In addition, we design our process to ensure high-integrity braze joints in a wide array of materials e.g., copper, stainless steel, and nickel-based alloys.
The Hydrogen Furnace Brazing Process
Hydrogen Furnace Brazing Assures High-Quality Assemblies
Hydrogen furnace brazing reduces oxides present on the surface of the parent materials. Therefore, it produces ultra-clean, high-integrity assemblies. Examples of assemblies fabricated by VPE e.g., electron accelerators, cyclotrons, sensor windows, as well as production aerospace assemblies.
Controlled Dew-Point Processing Prevents Oxidation
The hydrogen gas must be of certain purity to affect the wetting of the molten braze filler alloy on the parent materials. In fact, in many instances, a very dry (dew point less than -60°C) hydrogen atmosphere is required to prevent oxidation of parent materials such as stainless steel. However, materials such as copper use a wet hydrogen atmosphere in brazing or other thermal processing.
Alternate Methods Available for Niobium and Titanium Parent Materials
Niobium and titanium embrittle with reaction to the hydrogen gas. Therefore, they are not suitable for brazing in a hydrogen environment. However, these two metals may be brazed in a very clean inert atmosphere such as argon. Alternative joining processes to use are vacuum brazing and diffusion bonding.
Capabilities of Hydrogen Furnace Brazing
VPE’s extensive experience with hydrogen-brazed ceramic-to-metal assemblies assures the highest integrity assemblies for critical service, e.g.:
- Routinely meet helium leak-tight specifications to 2E-10 atm cc/sec.
- Controlled dew point processing enables VPE to selectively oxidize and treat products for specialized applications.
- VPE uses hydrogen brazing to manufacture seals and feed-throughs in high volumes.
- Ability to braze materials up to 18 in. x 18 in. x 100 in.
- We have both vertical as well as horizontal loading furnaces
- Temperature capabilities to 1250°C (2,282°F)
- Furnaces as well as induction brazing equipment
- Ceramic and refractory metal tooling and fixtures for consistent component fit-up and alignment.