The mechanisms of element redistribution in the surface layer of multicomponent alloys during their irradiation by high power pulsed ion beams

Abstract

It is shown that redistribution of elements in the surface layer proceeds depending on a type of the stable diagram ("based" element-alloyed element) if treatment by high power pulsed ion beam takes place under the melting condition, when irradiation has been conducted at low values of ion current density (j<60 A cm'2). Here the impurity having a coefficient of distribution (ki) lesser 1 is supplanted by the solidified front to the surface but if ki>1 than the element is concentrated in the zone between matrix and solidified alloy. This mechanism and else a mechanism of intense evaporation of volatile components proceed during irradiation at higher values of j. At j>120-140 A cm'2 the chemical composition of the surface changes "from point to point” to a great extent due to crater formation.