Vacuum Brazing

At HTA, inspiration is at the heart of everything we do. We are a NADCAP accredited heat treat facility and exemplify excellence by more than living up to the standards of vacuum brazing set forth in AWS C3.7 as well as solution treating and artificial ageing in accordance with AMS2770. Our commitment to excellence ensures that we hold ourselves to the highest possible standards for our customers’ satisfaction.

Vacuum brazing is a specialised form of furnace brazing that provides superior bonding results. This type of metal joining technique forms leak tight, non-corrosive, and stronger connections than any alternative methods. It works by creating a vacuum in the furnace during the brazing process which achieves much cleaner and flux-free joints with high strength and integrity.

The components to be joined are first positioned together and fixed, if necessary, through fixturing, staking or a combination of these methods.

Vacuum brazing provides a cost-effective solution for many types of joins with great reliability and consistent quality!

  • Simultaneous vacuum brazing of multiple joints
  • Uniform heating and cooling for consistent metallurgy
  • No heat affected zone (HAZ)
  • Reliable and repeatable
  • Furnace batch process for one or a thousand assemblies
  • Fluxless brazing – no post braze cleaning
  • Simple or complex assemblies with varied component types
  • Clean, bright assemblies
  • Leak tight, high strength joint area

Stainless steel, Titanium, Stellite, Molybdenum, Carbon steel, Carbide, Copper and Ceramic.

Filler Materials or braze mediums include:
– Aluminum
– Copper
– Nickel
– Silver

  • The size and shape of items that can be vacuum brazed depends on the type of equipment operated by the heat treater. For large items, check the availability of suitably-sized facilities at an early stage.
  • The process best suits joints in parallel planes that can be brazed horizontally. These usually are flat panel-type structures

Complex shapes and designs need to be carefully thought out to allow braze mediums to flow in the capillary action, complex designs and incorrect braze mediums and preparations can cause the braze to be unsuccessful.

It can be noted that Vacuum Brazing is a very successful method of joining dissimilar materials or complex components compared with alternate methods when correct designs and jigging have been established with repeatable computer controlled processes.

All of the following information should be included if possible. If uncertain, ask your heat treater before producing a specification:

  • Material: type, grade, and the standard from which it is drawn, with drawing, composition and mill certificate where available.
  • Braze medium or filler material
  • Any general standards applicable (national, international or company) that contain relevant details which must be adhered to.
  • Existing condition; e.g. details of any prior heat treatment, such as hardening and tempering, solution treatment and ageing, intended to establish mechanical or other properties.
  • The level of mechanical properties required.
  • The type(s) of testing required; e.g. hardness (Vickers, Brinell), tensile etc. and any special locations for testing or the removal of samples for test pieces.
  • Requirements for any special certificates or data to be provided by your heat treater.

Guidance and information is always available from our experience heat treatment professionals.

Our procedures and work instructions are fully documented under our AS 9100 and ISO 9001 quality management systems.