Direct Extrusion or Forward Extrusion
The
equipment consists of a cylinder or container into which the heated
metal billet is loaded. One end of the container, the die plate with
necessary opening is fixed. From the other end plunger or ram compresses
the metal billet against the container walls and die plate, thus the
forcing it to flow of metal in the forward direction through the die
opening.
Acquiring
the shape of the opening the extruded metal is then carried by the
metal is then carried b the metal handling system as it comes out of the
die. A dummy block which is a steel disc of about 40mm thick with a
diameter slightly less than container is kept between the hot billet and
the ram to protect it form heat and pressure. In direct extrusion, the
problem of friction prevalent because of the relative motion between
heated metal billet and cylinder walls. To reduce this friction
lubricants are to be used. To reduce the damage to equipment, extrusion
is finished quickly and the cylinder is cooled before further extrusion.

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