A pre mixed metal powder, meeting your material
specifications, is gravity fed into the die cavity using
a feed shoe. The "green" part is molded inside
the tooling, in most cases to the components final
net shape, and then ejected from the die. The irregular
shaped iron particles interlock together during the
compaction and allow for the parts to be handled in this
green state and retain their shape without excessive damage
or chipping. The force required to compact the green parts
to size is typically around 30 psi. In this state the parts
have a relatively indefinite shelf life due to the lubricant
in the powder forming a protective layer on the parts
and keeping them essentially rust free.
Sintering
Next step is the sintering operation. Parts are loaded
into a sintering furnace at approximately 2050° F. The
furnace chamber is filled with a protective atmosphere
generally consisting of hydrogen and nitrogen to assist
with de-lubing the parts and protecting against
decarburization. The parts will see a soak time at
temperature of at least 30 minutes to achieve an adequate
sinter, bonding of the iron particles, and will spend
another 30-45 minutes in a cool down portion at the
discharge end before exiting the furnace. In many cases
the parts at this state are ready for use and/or assembly
at the customer location. Many other value added
operations may also be performed to the parts depending
on the component requirements.
Secondary Operations
As with any steel part a number of secondary operations
are available to finish the component. One of the strengths
of TPI is the ability to readily provide a wide assortment
of secondary operations such as CNC machining, heat
treatment, zinc plating, and many other operations.
(see our Services
and Capabilities page for a complete list.
TPI Powder Metallurgy 12030 Beaver Rd.
P.O. Box 69
St. Charles, MI 48655-0069
Ph: 989-865-9921 • Fax: 989-865-9924
Email:tpiparts@tpipm.com
