Abstract: A strong lightweight composition containing inorganic coated microparticles which, when dispersed in a binder, produce a matrix having broad band absorption properties for electromagnetic radiation in the infrared and microwave regions and is useful as a thin coating or as a structural composite material in various applications for multispectral absorbers. The microparticles have a mean diameter of from 1 to 500 microns and are coated with the reaction product of a metal and a nonmetal.

Abstract: A strong lightweight composition containing metal coated microspheres has very broad band absorption properties for electromagnetic radiation and is useful as a thin coating or as a structural composite material in various applications. The microspheres have a diameter of from 1 to 350 microns and contain at least one radiation absorbing material selected from the group consisting of carbon, ferrites, magnetite, iron, nickel and cobalt, and have a thin-coating of metal on the microsphere surface. The metal coating is present at a weight percentage of 0.01 percent to 22 percent.