Vacuum Brazing and Heat Treatment

Aluminium Vacuum Brazing is a fluxless brazing process that is performed under high vacuum in a heated chamber using pre-placed or clad aluminium filler material. This process allows for the incorporation of internal fluid passages or galleries that can be used for the control of heat inputs/outputs of components that have specific heat operating ranges. Some advantages of Aluminium Vacuum Brazing include:

  • High strength joints in heat treatable aluminium alloys that enable light weight heat exchangers to be manufactured with superior structural integrity;
  • Fluxless operation meaning no potentially harmful residues or contaminates;
  • Excellent conductivity, both thermal and electrical, providing exceptional heat rejection characteristics while maintaining electrical integrity;
  • Greater freedom in design of products with intricate internal fluid passages or thin wall applications;
  • Greater reliability and durability in high stress design application compared to bolted or adhesive bonded applications; and
  • Relative low cost solutions for high end designs.

In association with Aluminium Vacuum Brazing, returning heat treatable brazed workings to a tempered state, through Solution Heat Treatment and Artificial Aging, is key to the performance and structural integrity of high stress components.  This is achieved in the PWR, specially designed, Solution Heat Treatment Furnace. This specialised equipment incorporates PLC controlled heating cycles with an automated, programmable, integral spray quench system that reduces residual stress during the quenching operation resulting in stable, high quality post braze components ready for final machining processes.

Applications for Aluminium Vacuum Brazed and Heat Treated components include, but are not limited to the following:

  • Cold plates – for both land based and aeronautical applications, cooling electronic components and power units;
  • Formula 1 and Formula E race-car platforms
  • Battery cell cooling/heating for electric vehicles;
  • Autonomous vehicles;
  • Airborne electronics and enclosures;
  • Radar installations and other military applications.
Vacuum Brazing is not limited to Aluminium. PWR’s capability also extends to high strength superalloys including Titanium, Nickle based and Chromium based metals such as Inconel and Heat Resistant Stainless Steels. These materials may also be brazed in the vacuum furnace with such alloy fillers as Silver, Nickle and Gold to provide superior joint interfaces.

PWR extends its brazing capability with two Controlled Atmosphere Brazing (CAB) furnaces, the first being a continuous belt with the second being a single batch type furnace. Controlled Atmosphere Brazing processes are performed in a Nitrogen atmosphere where pre-fluxed assemblies are joined together with pre-placed clad aluminium fillers, sheets or pastes that produce strong, leak-free joints in lower strength aluminium alloys for applications such as Radiators, Oil Coolers, Intercoolers and other Heat Exchangers.