Structure and Microporosity of Ion-Plasma Condensed Coatings Deposited from a Two-Phase Vacuum-Arc Discharge Plasma Flow Containing Evaporated Material Microdroplets

Influence of Surface Layer Condition of Al2O3+TiC Ceramic Inserts on Quality of Deposited Coatings and Reliability during Hardened Steel Milling

“…To differentiate the defects of the formed coatings into those related to the condition of the ceramic substrates and the technological features of the condensation processes, it is necessary to consider the microstructures of coatings deposited under identical conditions on ceramic substrates after additional lapping and polishing, which have minimal defects (Figures 7b and 8b). A comparison of the presented SEM images of microstructures and 3D profilograms with the data of Figures 7a and 8a shows that the coatings deposited on "defect-free" ceramic substrates only have well-known defects and features associated with the processes of coating synthesis, crystallite growth and micro-drops formation [66,67]. It should be noted that it is conditionally considered that if the SEM analysis (a quite fine study) does not reveal defects, then such a surface can be regarded as "defect-free" in comparison with the gross defects of industrial samples.…”

“…(a) (b) (a) (b) Coatings 2022, 12, x FOR PEER REVIEW 12 of 24 deposited on "defect-free" ceramic substrates only have well-known defects and features associated with the processes of coating synthesis, crystallite growth and micro-drops formation [66,67]. It should be noted that it is conditionally considered that if the SEM analysis (a quite fine study) does not reveal defects, then such a surface can be regarded as "defect-free" in comparison with the gross defects of industrial samples.…”

Investigation of the Influence of Microdroplets on the Coatings Nanolayer Structure

“…In [31], the studies simulate the influence of parameters-such as the microdroplet velocity on impact, the relative distances between two successive microdroplets of molten metal, the substrate temperature, and the microdroplet sizes-on the morphology of the final shape of a microdroplet solidified after the impact. The mechanisms of the microdroplet formation are also considered in detail in [1,32,33]. All the simulation results presented indicate that upon contact of a liquid or highly ductile microdroplet with the deposition surface, the microdroplet is subjected to deformation, and it forms a typical lens-shaped structure, sometimes with a torus-shaped formation along the microdroplet boundaries.…”