Ferro Corporation
Carbide, nitride and silicide enhancers for laser absorption

Abstract:

A universal or all-purpose laser marking composition for forming satisfactorily dark laser marks on a wide variety of substrates is provided. The marking composition comprises an enhancer of nitrides, carbides, silicides, and combinations thereof. The enhancer may be selected one or more of ferromanganese, ferrosilicon, Fe.sub.xSi.sub.(1-x) where X can range from about 0.005 to 0.995, Fe.sub.5Si.sub.2, MgFeSi, SiC, CaSi, (Co)Mo, MoSi.sub.2, TiSi.sub.2, ZrSi.sub.2, WSi.sub.2, MnSi.sub.2, YSi, Cu.sub.5Si, Ni.sub.2Si, Fe.sub.3C, Fe.sub.7C.sub.3 and Fe.sub.2C, MoC, Mo.sub.2C, Mo.sub.3C.sub.2, YC.sub.2, WC, Al.sub.4C.sub.3, Mg.sub.2C, Mg.sub.2C.sub.3, CaC.sub.2, LaC.sub.2, Ta.sub.4C.sub.3, Fe.sub.2N, Fe.sub.3N, Fe.sub.4N, Fe.sub.7N.sub.3, Fe.sub.16N.sub.2, MoN, Mo.sub.2N, W.sub.2N, WN, WN.sub.2, and combinations thereof and combinations thereof. Upon disposing the marking composition on a substrate and exposing the marking composition to laser radiation, the marking composition absorbs the laser radiation, increases in temperature, chemically bonds with the substrate, and when formed on each of a metal, glass, ceramic, stone, and plastic substrates, the mark has a negative .DELTA.L dark contrast value of at least -1 compared to a mark formed by the marking composition without the enhancer.