LAYERED METALLIC MATERIALS

摘要

1,210,180. Token. VEREINIGTE DEUTSCHE METALLWERKE A.G. 14 May, 1968 [20 May, 1967 (2)], No. 22937/68. Heading G4X. [Also in Division B3] A metallic material comprises two constituents arranged alternately in at least three layers, the one constituent being magnetizable, made of nickel, and the other being non- magnetizable, made of a copper-nickel alloy having 5 to 60% nickel. The material may be in the form of a coin or disc with, for example, three layers, the inner layer being either nickel or copper nickel alloy. A set of coins comprises coins having a nickel layer or layers of a thick ness or total thickness, respectively, of 2.6%, 4.0%, 6.0%, 8.5%, 12%, and 17%, respectively, of the total thickness of each coin. The nickel thickness of a coin may lie, however, between 1 and 50% of the total thickness. The material may be made by an electrolytic thick nickel plating process, followed by cold rolling and diffusion annealing. Alternatively the layers may be applied by a hot or cold rolling process. Preferably the two outer layers of a three-layer coin are of equal thickness.