HIROSHIMA - Mazda Motor Corporation has developed the world's
first direct spot joining technology to join steel and
aluminum.
This new technology - Mazda has applied for more than 20 patents
related to this process - was first employed in 2003 in the
development of the Mazda RX-8 sports car that used friction heat to
join separate aluminum sheets.
The technology has evolved, and will be used to join the trunk
lid and bolt retainer for the all-new Mazda MX-5 sports car that is
scheduled to go on sale in Australia about October.
Until now welding two different metals such as steel and
aluminum has been a difficult task. However, by optimising the
rotating tool shape and joining characteristics, and by using
galvanized steel on one side, joining steel and aluminum has been
made possible.
The process is similar to that of joining two pieces of
aluminum, when a joining gun holds the parts from both sides with a
welding tool. The joining tool is then made to spin while force is
applied, which in turn generates frictional heat that subsequently
joins the aluminum materials to the steel sheet metal.
Galvanized steel helps prevent the galvanic corrosion that
results from the contact of two different types of metal.
Compared with conventional joining techniques such as riveting
or clinching, steel and aluminum spot friction welding makes it
easier to join materials that are difficult to deform, such as
aluminum casting and high tensile steel. Additionally, running
costs can be reduced because riveting becomes unnecessary.
This innovative technology makes it simple to join steel and
aluminum, and improves the potential of coupling aluminum parts to
steel in vehicle bodies, and has other applications in a wide range
of industrial uses.
The technology contributed significantly to Mazda's vehicle
weight reduction "gram strategy" program during the development of
the MX-5 sports car, as well as lowering costs.
For further information contact:
Alastair Doak
National Public Relations Manager
Phone: (03) 8540 1962
Mobile: 0418 626 329
Email:adoak@mazda.com.au