Conditions and mechanisms of the defects formation in vacuum ion-plasma coatings

Abstract

Abstract The results of studies of various structural features of vacuum ion-plasma PVD-coatings qualified by the authors as coating defects, are presented. Defects include a large volume of porosity, deformation of crystallites, exfoliation, etc. The systematization of defects is presented, depending on the nature of their nucleation (droplet, substructural, and growth defects) and on the character of their distribution in the coating (regular and stochastic). Coatings of various chemical composition were obtained by the method of ion-plasma deposition using both arc and magnetron evaporators. Experimental results are presented, the main array of which was obtained using a double-beam (ion / electron) electron microscope. A separate study on specific substructural defects was conducted. Statistical data on their geometrical dimensions and distribution in coatings is presented. Defects of this type have micron sizes (up to 5 μm in diameter) and a cylindrical shape with an axis perpendicular to the surface of the coating. A hypothesis about the dislocation mechanism of their nucleation on screw dislocations and the spiral mechanism of their growth has been put forward and substantiated.