Valaminen

Valaminen is a manufacturing process in which a liquid material, most commonly metal, is poured into a mold and allowed to cool and solidify to form a component. The process enables production of complex shapes, internal channels, and near-net-size parts with relatively simple tooling, making it suitable for prototypes and large-volume runs alike. While metal casting is most common, casting can also be applied to ceramics and certain polymers through resin or ceramic slurries.

The general sequence consists of pattern creation, mold making, removal of the pattern, mold assembly, and pour, followed by solidification and finishing. Many casting methods exist, including sand casting (loose-sand molds), investment casting (ceramic or wax patterns in a shell), die casting (high-pressure metal in reusable molds), shell molding, plaster-mold casting, lost-foam, centrifugal casting, and permanent-mold casting. Gating systems feed the mold to control flow and reduce porosity; feeders and risers compensate for shrinkage as the metal cools.

Common materials are iron and steel, aluminum and magnesium alloys, and copper, zinc, and nickel-based alloys. Casting is favored when parts are large, have complex geometries, or require near-net shapes to reduce machining. Limitations include dimensional tolerances, surface finish quality, and internal defects such as porosity or shrinkage, which depend on mold design, material, and process parameters.

Quality control uses visual inspection, dimensional measurement, and non-destructive testing to detect voids, cracks, or inclusions. Safety and environmental considerations address high-temperature handling, mold materials, energy use, and sand or ceramic waste management.