One of the properties of PVD hard coatings that has an important influence on their tribological behaviour is the surface topography. This strongly depends on the topography of the bare substrate and the topography induced by the coating-deposition process (ion etching and deposition). In particular, the formation of growth defects significantly alters the surface morphology and the roughness. In this invited lecture, presented at the 13th interntional symposium on sputtering & plasma processes, the relationship between the growth defects and the tribological, corrosion and oxidation properties of PVD hard coatings is explained.
B.04 Guest lecture
COBISS.SI-ID: 28705831In deposition of thin films by magnetron sputtering, it is very important to understand the basic physical processes in the plasma. Until recently, common knowledge for magnetron plasma was based on the assumption that it was distributed evenly along the circle. Using a high-speed camera Dr Matjaž Panjan proved that in DC magnetron sputtering plasma is not evenly distributed, but localized in small areas of regular shapes. These areas resemble elongated arrows and form different symmetrical patterns which change their shape in dependence of working pressure and sputtering parameters. The plasma areas rotate on the magnetron plain with an angular velocity of 2–10 km/s. They have an important influence on the electron and ion transport in the magnetron plasma.
B.05 Guest lecturer at an institute/university
COBISS.SI-ID: 28455463With the aim to develop hard coatings characterized by both, high hardness and high resistance to cracking, synergy between nanolayered and nanocomposite design was made and nanolayered TiAlN/TiSiN and CrAlN/TiSiN coatings were produced. Monolayer TiAlN, nanocomposite TiSiN and multilayer TiAlN/TiSiN were also studied in order to find the relation between the coating design and their properties. All coatings were deposited with 1-fold, 2-fold and 3-fold rotation. It is shown that coating design and type of rotation have great influence on coating microstructure and texture, and in this way on their mechanical properties, resistance to cracking, adhesion between coating and substrate, surface topography and tribological behavior. Nanolayered and nanocomposite coatings are characterized by compact nanocrystalline microstructure, while monolayer TiAlN coatings have columnar structure with larger crystalline grains. By increasing the number of rotational degrees from 1 -fold to 3-fold size of crystalline grains decreases and microstructure becomes more dense. Therefore, nanolayered and nanocomposite coatings deposited with 2-fold and 3-fold rotation are characterized by the highest hardness, highest resistance to cracking, highest wear resistance and the smoothest surface topography.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 28907303