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DaimlerChrysler Researchers Develop Ceramics Suitable For Use in Automobile Brakes

13 March 2000

DaimlerChrysler Researchers Develop Ceramics Suitable For Use in Automobile Brakes

    AUBURN HILLS, Mich. and STUTTGART, Germany, March 13 Researchers from DaimlerChrysler have developed a cost-effective, fiber-
reinforced ceramic for use in brakes.
    Ceramic brakes have several advantages over conventional materials.  They
are heat and rust-resistant.  They are not subject to wear or warping and thus
are maintenance free.  In addition, they are one-third the weight of steel.
    However, fiber-reinforced ceramics, which overcome the problem of
brittleness of traditional ceramic materials, have been too expensive for
large-scale use.  Now, with a special combination of carbon and silicon
developed by DaimlerChrysler researchers, brake discs made from fiber-
reinforced ceramics can be produced on a large scale.
    Initial field studies have shown that ceramic brakes perform reliably
after 180,000 miles (300,000 kilometers) of use.  Brake disk changes are not
needed, saving the time and expense of maintenance.
    In the method of producing fiber-reinforced ceramics developed by
DaimlerChrysler researchers, short carbon fibers, carbon powder and resin are
first compressed and then heated to and held at about 1830 degrees Fahrenheit
(1000 degrees Celsius) for some time.  During this process, the carbon bonds
to form a stable framework similar to when pieces of ice fuse together.  When
cooled, this material can be shaped into the desired form.
    After grinding the brake disk blank to size, the finished blank is
reheated together with silicon, causing the pores in the carbon framework to
absorb the silicon.  This fiber-reinforced ceramic material cools overnight,
and the dark gray brake disc is ready for use.