bimetallisch

Bimetallisch, in English bimetallic, describes a material or object that consists of two distinct metals bonded together. The different metals are chosen to combine desirable properties—such as hardness, strength, corrosion resistance, electrical or thermal conductivity, or wear resistance—not easily achieved by a single metal. Methods to produce bimetallic structures include cladding, diffusion bonding, roll bonding, and explosive welding. The result is a composite material or component whose behavior is determined by the combination and geometry of the two metals.

In engineering, bimetallic elements are used in laminated sheets, plates, and components. A common example is the bimetallic strip, formed from two metals with different coefficients of thermal expansion. When temperature changes, the strip bends, which can actuate switches in thermostats and protection devices. Bimetallic constructions are also employed to tailor surface properties such as wear and corrosion resistance or to achieve layered functionality in electronics, energy applications, and mechanical parts.

In currency and numismatics, bimetallic coins use two metals, typically a core of one metal surrounded by a ring of another. This design improves durability, enables easy denomination recognition, and provides anti-counterfeiting features. Historically, the concept of bimetallism referred to monetary systems that used two metals as legal tender standards, commonly gold and silver. The term is used in German and Dutch contexts to describe both material bonding and monetary concepts.