extruded

Extruded refers to a material or product that has been shaped by extrusion, a process in which a material is forced through an opening or die to create a fixed cross-sectional profile. The extrusion process can align the material’s grain and produce long sections with consistent geometry, making it widely used in manufacturing and fabrication. Extrusion also denotes volcanic products that are pushed onto the surface during a eruption.

In manufacturing, extrusion can be performed as hot extrusion, cold extrusion, or a combination. Direct extrusion moves the billet through a stationary die with the ram applying force, while indirect extrusion moves the die or container to reduce friction. Hollow and solid sections are possible, and some processes produce tubes or complex profiles by using mandrels or multiple dies. Heating the material reduces the required extrusion force, but can alter microstructure and surface finish; cold extrusion yields high-strength parts at room temperature.

Materials commonly shaped by extrusion include metals (such as aluminum, copper, steels, and magnesium alloys), polymers (plastics like PVC and polyolefins), ceramics, and certain food products (pasta, snacks, cereals). Advantages of extrusion include the ability to create long lengths with near-net shapes, good surface finishes, strong dimensional control, and efficient material use. Limitations involve costly tooling and dies, wear and maintenance, material compatibility with high temperatures, and potential residual stresses or anisotropy in the finished parts.

Applications span architectural extrusions (profiles and channels), tubing and piping, heat exchangers, automotive components, electrical conduits, and food products. In geology, extrusion is used to describe lava or magma that emerges onto the surface, forming extrusive rocks.