摘要：

A composite structure is described in which a substrate is covered with an adherent protective/ornamental layer consisting of single phase cobalt oxide containing iron in solid solution therein. By way of example, a ferrous metal substrate to which a layer (at least about 0.5 mil thick) of cobalt has been applied is treated to provide a black, dense, coherent scale possessing a deep luster and high reflectivity. This enamellike coating is produced by (a) heat treatment of the plated substrate in an atmosphere not oxidizing to either cobalt or iron in order to interdiffuse the cobalt and iron and produce a cobalt-iron surface composition in which the iron content may range from about 2 to about 20 percent by weight and (b) oxidation of the plated substrate after it has been heated to temperatures in the range of 900° to 1,200° C.

展开