the ultimate stainless manifold? (no direct Audi content)

[Steinbru@VNET.IBM.COM]

VACUUMING METALS INTO MOLDS

   One day, a peek under the hood of a car might reveal an
exhaust manifold of gleaming stainless steel instead of dull
cast iron.
   Today, 25 percent of an automobile's fuel goes toward cool-
ing down the motor so the cast iron components won't self-
destruct. Able to withstand higher temperatures, stainless
steel parts would allow car engines to run more efficiently.
   This year, several automakers will begin making stainless
steel exhaust manifolds using a new technology that allows
molds to be filled in an unusual way. Instead of being poured in
from the top, the molten metal is drawn in from the bottom by
means of a vacuum-similar to how a milkshake is sucked
through a straw.
   "The process is capable of making very thin-walled steel
parts, enabling people to design parts that they couldn't have
before," says G. Dixon Chandley, president of Metal Casting
Technology in Milford, N.H.
   Pouring often splatters molten metal onto the sides of the
mold, leaving defects in the finished piece. With the vacuum tech-
nology; however a manufacturer can control how fast the mold
fills and thus improve the quality of the finished piece.   C.W.
(from Science News Vol.155 No.5)