Electron beam welding provided the answer to a tough joining problem faced by Industrial Members GEC Alsthom Traction (now Alstom Transport) in welding 800 large heat sinks for use on trains for the UK rail network. Heat sinks are easily visible around the skirts of networker trains and are used both to cool the invertors and to provide an environmental cover.
GEC wanted to manufacture larger units and, with its manufacturing press running at maximum capacity, it was decided to join pairs together using electron beam welding. The extrusions were made of an aluminium silicon magnesium alloy (6063) and measured approximately 600mm by 300mm with a 16mm wide joining face. Eight pairs were clamped to the transverse table of TWI's 150m 3 electron beam chamber. The EB gun installed in the chamber at the time was capable of 100kW of output, but for this relatively small production job just 7kW of power was needed (today TWI operates numerous electron beams, with capabilities ranging from 5kW to 150kW). Each weld took about three minutes to complete so each clamping set-up was finished in less than an hour.
Electron beam was found to provide a high tech solution for mass production without the need for preheating or filler wire and with minimum distortion.
Please contact us for more information on how TWI's cutting edge electron beam technologies can benefit your business, or for more general information on TWI's wide range of services to the rail industry.