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LINKING PEOPLE, JOINING NATIONS
the Danjang Kunshan Grand Bridge in China, opened in 2011, occupied a distance of 164.8
kilometres of road and rail including the Beijing-Shanghai high-speed rail line, officially
being the longest bridge in the world. It is important to note that its construction consisted
of around 450 000 tons of steel in its welded structure and without the facility to produce
continuous welded track, high-speed rail travel would not have advanced to the stage as we
know it today.
Magnetic levitation as a technology has the means to take speeds of high-
speed trains to well above the current levels of 300 km/hr, perhaps approaching
600-700 km/hr. Recently, a trial Japanese seven-car magnetic levitation train set the world
record for a high-speed trainwith a speed of 600 km/hr in a short test run.
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There is expectation
that the rail journey from Tokyo to Nagoya (286 km) will take only 45 minutes at a speed of
500 km/hr with the commercial introduction of a Maglev train in 2027. Japan is hoping
to sell its high-speed rail technology overseas as part of an attempt to revive the world’s
third biggest economy through infrastructure exports.
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For this, eventually, to happen the
supporting structure and guide ways will require state-of-the-art welding technology to
ensure the integrity and safety of high-speed trains using magnetic levitation principles are
maintained.
The heart of all progress is not just the major structures that stand out for
all to see. It is the smaller, less visible world of nano- and micro-technology
that ensures that the larger world can operate and fulfil its operational function.
A failure of a small switch or circuit board can completely disrupt a whole
railway system or power supply and cause significant economic loss and
inconvenience. Welcome to the world of microjoining! The involvement of
microjoining in the electronics, instrument, and actuator and sensor industries
is as important and as extensive as that of welding in other manufacturing
industries.
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The proper functioning of small mechanical devices and
electronic systems in the aerospace, medical, telecommunications, computer,
automotive and oil and gas industries is critically dependent on the use of
efficient and reliable microjoining techniques.
The welding industry has responded to these challenges and IIW has remained
actively involved in these activities through participation in Commission VII
Microjoining
and Nanojoining
(C-VII) and the preceding Select Committees headed by Prof. Norman
Zhou (Canada), a group with the goal to identify, develop and create best practices in
microjoining and nanojoining techniques. Miniaturisation of medical devices and the use of
implantable prosthetic materials in the human body have also increased markedly in recent
years meaning that welding in such situations has had to keep up with human expectations.
This has required special joining techniques such as ultrasonic and thermosonic welding