This paper demonstrates the results of investigations on operation regimes of vacuum-arc sources, affecting the element composition and properties of implantation and deposited ion-mixed structures. Operation of an ion-electron plasma and sources with combined film deposition and ion bombardment is described. The results on high-dose implantation are presented. We also report the results on changing mechanical properties and structures of metals and alloys. We shall briefly mention sources of high-power ion beams of nanosecond duration and their application in improving the mechanical properties of surface layers of metals and alloys.