Extrusion is the process by which long straight metal parts can be produced. The cross-sections that can be produced vary from solid round, rectangular, to L shapes, T shapes. Tubes and many other different types. Extrusion is done by squeezing metal in a closed cavity through a tool, known as a die using either a mechanical or hydraulic press. Extrusion produces compressive and shear forces in the stock. No tensile is produced, which makes high deformation possible without tearing the metal. The cavity in which the raw material is contained is lined with a wear resistant material. This can withstand the high radial loads that are created when the material is pushed the die.
Extrusion produces compressive and shear forces in the stock.
Extrusions, often minimize the need for secondary machining.. Surface finish for steel is 3 µm; (125 µ in), and Aluminum and Magnesium is 0.8 µm (30 µ in). The extrusion process can produce a wide variety of cross-sections that are hard to produce cost-effectively using other methods. Minimum thickness of steel is about 3 mm (0.120 in), whereas Aluminum and Magnesium is about 1mm (0.040 in). Minimum cross sections are 250 mm2 (0.4 in2) for steel and less than that for Aluminum and Magnesium. Minimum corner and fillet radii are 0.4 mm (0.015 in) for Aluminum and Magnesium, and for steel, the minimum corner radius is 0.8mm(0.030 in) and 4 mm (0.120 in) fillet radius.
Cold Extrusion
Cold extrusion is the state of the art technology that is becoming more and
more popular. parts produced with this method are being used more and more
in industry thanks to their great stability and particularly high quality
surface. Cold extrusion is a production method within the area of forming
technology, in which items in a wide variety of shapes are manufactured from
blanks. During the cold forming process the blank undergoes plastic deformation
in the pressing tool. Cold extrusion is the process done at room temperature
or slightly elevated temperatures. This process can be used for most materials-subject
to designing robust enough tooling that can withstand the stresses created
by extrusion. Examples of the metals that can be extruded are lead, tin, aluminum
alloys, copper, titanium, molybdenum, vanadium, steel. Examples of parts that
are cold extruded are collapsible tubes, aluminum cans, cylinders, gear blanks.
The advantages of cold extrusion are:
No oxidation takes place.
Good mechanical properties due to severe cold working as long as the temperatures
created are below the re-crystallization temperature.
Good surface finish with the use of proper lubricants.
Extrusion is done by squeezing metal in a closed cavity through a tool, known
as a die using either a mechanical or hydraulic press.
Cold Forging
The major advantages of cold forging are close dimensional tolerances, good surface finish quality, and the use of lower cost materials to obtain the required strength by work hardening without requiring heat treatment. The lower values require additional attention in processing, particularly the maintenance of tool surface finish.
Heckler AG and Cold Extrusion
Heckler AG specializes in cold extrusion technology for
COLD EXTRUSION
