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Remanufacturing and Advanced Machining
of thin tribo-films, from several nanometers to a micron thick, on the friction surface by interaction with the environment. Adaptive coating application weakens
internal impact and leads to practical improvements in two domains: (1) tool life
enhancement, and (2) improved workpiece quality in terms of a better surface finish, improved dimensional accuracy, etc. The author gives an example of Al-rich
TiAlN and AlTiCrN families of nanocrystalline hard plasma vapor deposited coatings which due to their adaptability mostly outperform other categories of coatings
under aggressive and extreme cutting conditions. The author is of the opinion that
future generations of hard coatings used in applications under extreme tribological conditions must become complex engineering adaptive systems to be able to
sustain a number of external impacts and adapt to changing operating conditions
(Fox-Rabinovich, 2013).
2.7 TITANIUM NITRIDE NANOCERAMIC
MATRIX COMPOSITE COATINGS
The processes and equipment for synthesis of TiN coatings are well established and
commonly applied in industry. These processes are envinronmentally clean and the
coatings are chemically inert toward the environment. Moreover, their application as
strengthening and decorative coatings is economically profitable. Practical applications of titanium nitride involve several industrial branches and motivate new directions of physical and technical research.
Titanium nitride (TiN) is a gold-yellow ceramic material of high hardness up
to 2000 kg/mm 2 , high decomposition temperature of 2949°C, and high chemical
stability at room temperature (van Hove et al., 2015). It has a cubic structure similar to NaCl (Tominaga et al., 2012). Along with chromium nitride (CrN), alumina
(Al 2 O 3 ), titanium carbide (TiC), diamond-like carbon (DLC), and tungsten carbide/
carbon (WC/C), titanium nitride belongs to the group of important ceramic coating materials that improve toughness, tribological properties, wear resistance, and
high-temperature stability of components (Maitra, 2014). Nanoceramic composite
coatings consist of a homogeneous isotropic multiphase mixture or several layers
of ceramic phases. Multilayer coatings have significant impact on wear mechanism,
having transition zones between their layers and thus hindering crack propagation,
since the cracking direction is from the coating surface to the substrate, unlike twodirectional cracking in single-layer coatings (Pogrebnjak et al., 2019).
The nanocomposites are beneficial because of improved hardness and oxidation
resistance higher than in coventional TiN coatings. However, nanocomposite coatings suffer from some limitations to possible particle sizes and material compositions due to restricted conditions and altered nanoscale material properties. As a
rule, nanocomposite coatings are deposited using physical vapor deposition (PVD)
or plasma-assisted chemical vapor deposition (PACVD). With application of laserassisted deposition techniques, it is possible to fabricate hard composite coatings
with nanocrystalline and amorphous phases. When the particle sizes are selected
appropriately, optimal dislocations and cracks in nano- and microscale in a material can be achieved. This way, the material can gain self-adjustment properties
Remanufacturing and Advanced Machining
of thin tribo-films, from several nanometers to a micron thick, on the friction surface by interaction with the environment. Adaptive coating application weakens
internal impact and leads to practical improvements in two domains: (1) tool life
enhancement, and (2) improved workpiece quality in terms of a better surface finish, improved dimensional accuracy, etc. The author gives an example of Al-rich
TiAlN and AlTiCrN families of nanocrystalline hard plasma vapor deposited coatings which due to their adaptability mostly outperform other categories of coatings
under aggressive and extreme cutting conditions. The author is of the opinion that
future generations of hard coatings used in applications under extreme tribological conditions must become complex engineering adaptive systems to be able to
sustain a number of external impacts and adapt to changing operating conditions
(Fox-Rabinovich, 2013).
2.7 TITANIUM NITRIDE NANOCERAMIC
MATRIX COMPOSITE COATINGS
The processes and equipment for synthesis of TiN coatings are well established and
commonly applied in industry. These processes are envinronmentally clean and the
coatings are chemically inert toward the environment. Moreover, their application as
strengthening and decorative coatings is economically profitable. Practical applications of titanium nitride involve several industrial branches and motivate new directions of physical and technical research.
Titanium nitride (TiN) is a gold-yellow ceramic material of high hardness up
to 2000 kg/mm 2 , high decomposition temperature of 2949°C, and high chemical
stability at room temperature (van Hove et al., 2015). It has a cubic structure similar to NaCl (Tominaga et al., 2012). Along with chromium nitride (CrN), alumina
(Al 2 O 3 ), titanium carbide (TiC), diamond-like carbon (DLC), and tungsten carbide/
carbon (WC/C), titanium nitride belongs to the group of important ceramic coating materials that improve toughness, tribological properties, wear resistance, and
high-temperature stability of components (Maitra, 2014). Nanoceramic composite
coatings consist of a homogeneous isotropic multiphase mixture or several layers
of ceramic phases. Multilayer coatings have significant impact on wear mechanism,
having transition zones between their layers and thus hindering crack propagation,
since the cracking direction is from the coating surface to the substrate, unlike twodirectional cracking in single-layer coatings (Pogrebnjak et al., 2019).
The nanocomposites are beneficial because of improved hardness and oxidation
resistance higher than in coventional TiN coatings. However, nanocomposite coatings suffer from some limitations to possible particle sizes and material compositions due to restricted conditions and altered nanoscale material properties. As a
rule, nanocomposite coatings are deposited using physical vapor deposition (PVD)
or plasma-assisted chemical vapor deposition (PACVD). With application of laserassisted deposition techniques, it is possible to fabricate hard composite coatings
with nanocrystalline and amorphous phases. When the particle sizes are selected
appropriately, optimal dislocations and cracks in nano- and microscale in a material can be achieved. This way, the material can gain self-adjustment properties