Powdered metal is a lower temperature casting process where metal powders
and binders are put into a mold and heated to a temperature below the
fluidization temperature of the metal. This is called sintering. The
purpose is to have something that needs very little to no machining
before assembly. It also results in some alloys and dispersions that
otherwise couldn't be achieved with conventional casting and can result
in some lighter parts since there remain some voids after the process is
done.
Strengths for the powdered metal they use for connecting rods are
somewhere between aluminum and steel as are the weights. They are also
stronger than most iron connecting rods. They can also "crack" the
connecting rod instead of machining the split. Conventional rods are cast
oval, the split is machined flat and the crank bore machined circular.
Powdered metal rods are sintered whole with a circular big end and a
groove where the split will be. The hole is finished, then they are
placed in a big press and broken along the groove line. This makes a
male/female grainy mating surface that will always go back together
during assembly in the perfect alignment, not subject to machining
tolerances.
http://www.asnt.org/publications/materialseval/basics/nov02basics/nov02basics.htm
Jon
Steven Trovato wrote:
>
> Yeah. What's a powdered metal rod?
>
> -Steve
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