Based in West Melbourne, EB Fusion specialises in electron beam welding (EBW), a metal joining technique used to create high-integrity welded joints.
The advantages of EBW include a high power density with very low overall heat input and therefore minimal distortion. EB welded parts require a minimal, if any, post-weld machining and unlike other fusion welding processes, they require no shielding gases. The weld quality is exceptional, with deep penetration and a narrow fusion zone resulting in near parent metal strength.
EBW is used for joining ferrous metals, light metals, and precious metals and their alloys to themselves or to each other, such as aluminium, nickel, copper, stainless steel, platinum, titanium, tungsten and tantalum. Typical applications include aerospace, automotive, marine and integrated electronics. The low heat input means that, for example, internally mounted, heat sensitive electronic packages may be sealed in a welded enclosure without damage.
EB Fusion provides a unique EBW service to industry Australia-wide, in conjunction with high-precision CNC turning and engineering capabilities, with a specific focus on metals and engineering thermoplastics such as polyether ether ketone (PEEK), polyphenylene sulphide (PPS) and polytetrafluoroethylene (PTFE).
The electron beam welding system
The EBW system is composed of an electron beam gun, a power supply, control system, work piece motion equipment, and vacuum-welding chamber. Fusion of the base metals eliminates the need for filler metals. The vacuum requirement for operation of the electron beam equipment eliminates the need for shielding gases and fluxes.
The electron beam gun has a tungsten filament, which is heated, freeing electrons. The electrons are accelerated from the source with high voltage potential between a cathode and anode. The stream of electrons then passes through a hole in the anode. The beam is directed by the magnetic forces exerted by focusing and deflecting coils. This beam is directed out of the gun column and strikes the workpiece.
The potential energy of the electrons is transferred to heat upon impact with the workpiece and cuts a perfect hole at the weld joint. Molten metal fills in behind the beam, creating a deep, finished weld. The electron beam stream and workpiece are manipulated by means of precise, computer-driven controls, within a vacuum welding chamber that consequently eliminates oxidation or contamination.
EBW offers a variety of benefits. It delivers the maximum possible weld penetration with the least amount of heat input, while causing minimal distortion and a narrow heat-affected zone (HAZ). EBW offers a high welding speed and can often reduce the need for secondary operations. Due to it being a computer-controlled process, EBW allows extreme precision and high levels of reproducibility, producing a clean, strong, homogenous weld under vacuum without the need for filler material. The vacuum environment also eliminates atmospheric contaminants in the weld. Exotic alloys and dissimilar materials can be welded. EBW frequently yields a zero-percent scrap rate, and it can be employed to salvage and repair both old and new components.
The vacuum chamber dimensions at EB Fusion measures 300mm x 300mm x 300mm, with a range of chamber extensions developed for specific job requirements. The system at EB Fusion can be configured to produce circular or rotary orientated weld paths, utilising a CNC rotary axis drive.