Pohjametalli

Pohjametalli, in metallurgy, refers to a metal that is not classified as a noble metal. In English, the corresponding term is base metal. Base metals are typically inexpensive, abundant, and more chemically reactive than noble metals such as gold, silver, and platinum. They are prone to corrosion and oxidation unless protected by coatings or alloys.

Base metals often serve as substrates for coatings, as components in alloys, or as the primary metal in a product. Common base metals include iron and its alloy steel, copper, aluminium, zinc, tin, and lead. Nickel and chromium are also treated as base metals in many contexts, especially when used as alloying elements or coatings, though they can exhibit relatively high corrosion resistance depending on the environment.

Processing and finishing methods are commonly applied to base metals to improve performance. Surface treatments such as galvanization (zinc coating on steel), electroplating (to apply a thin layer of another metal), painting, powder coating, and anodizing (notably on aluminium) are standard practices to enhance hardness, wear resistance, and corrosion protection.

Challenges associated with base metals include susceptibility to corrosion, tarnish, and galvanic corrosion when in electrical or chemical contact with different metals. Material selection for a given application balances factors such as mechanical properties, cost, availability, and environmental impact. Understanding pohjametalli involves recognizing its role as the practical, cost-effective workhorse in many industries, contrasted with the higher-value, corrosion-resistant noble metals used for premium applications.