külmekstrusiooni

Külmekstrusioon, also known as cold extrusion, is a metal forming process that shapes metal at or near room temperature. It involves forcing a metal billet into a die cavity under high pressure. This pressure causes the metal to flow and conform to the shape of the die. Unlike hot extrusion, cold extrusion does not require preheating the metal, which offers several advantages.

The process is typically performed on ductile metals such as aluminum, copper, brass, and low-carbon steels. Cold extrusion is known for its ability to produce parts with excellent surface finish and tight dimensional tolerances. It can also significantly improve the mechanical properties of the material, such as tensile strength and hardness, due to work hardening. This is because the plastic deformation at lower temperatures causes the metal's grain structure to become refined and elongated in the direction of metal flow.

Cold extrusion is a versatile process capable of creating a wide range of complex shapes, including hollow components, gears, shafts, and fasteners. It is often used in automotive, aerospace, and appliance manufacturing for producing precision parts efficiently. The main limitations of cold extrusion include the higher forces required compared to hot extrusion and the limited range of workable materials, as brittle materials cannot withstand the deformation. However, its ability to create strong, precise parts with minimal material waste makes it a valuable manufacturing technique.