Modifying the composition of a brass and bronze surface layer under a high power ion beam of a nanosecond duration

The change in the composition of the surface layers of brass LS59-1 and bronze BrOS10-10 under the action of a high power ion beam has been studied. Zinc depletion of the brass surface at a beam current density of $j\sim$ 50 A/cm$^2$ is shown; zinc enrichment of the surface layer is observed at $j >$ 150 A/cm$^2$, and a thin zinc layer is found to be formed across the entire surface. For bronze BrOS10-10, tin enrichment of the surface is registered only under a multiple effect of the beam at $j >$ 150 A/cm$^2$. Various mechanisms of modifying the elemental composition are considered.