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Protection and Restoration
the dispersed phase maintained in a suspended state or transported to the cathode.
Electric current passing through the suspension forms a coating on the surface of a
restored component. According to the authors, CGC can solve three main problems:
1. Application of metal coating to a worn surface during recovery of parts and
their hardening
2. Application of metal and other coatings to protect part surfaces from
corrosion
3. Application of protective and decorative coatings
In terms of reliability and durability of repaired vehicle parts, the first task is the
most important. Analysis of car parts coming to reparation shows that wear is
mostly below 0.1–0.3 mm, which makes coating more economically effective than
replacement of a worn part, especially when the parts are made of expensive alloy
steels. Application of powders based on tungsten carbide with a particle size below
1 μm, produced by electro-erosion dispersion from waste-sintered hard alloys as
a dispersed phase of composite galvanic coatings based on iron during restoration
and hardening of car parts, is possible. The resulting micro-hardness was close to
that of the original component, while relative wear resistance of the obtained composite galvanic coatings was increased compared to simple iron galvanic coatings
(Semenikhin et al., 2020). It is noteworthy that not only waste materials are reused
and worn parts repaired at reduced costs, but also life of repaired parts is increased.
Mayrhofer et al. (2005) point out that nanostructures have attracted increasing
interest in modern development of hard coatings for wear-resistant applications.
There is a direct relation between hardness and nanostructure, because hardness of
a material is determined by resistance to bond distortion and dislocation formation
and motion, which in turn depend on the amount and constitution of obstacles inside
the material structure. Based on TiB 2.4 , TiN–TiB 2 , Ti 0.34 Al 0.66 N, and Ti(N,B) as
model-coatings, the authors demonstrate development of self-organized nanostructures and their influence on mechanical properties of ceramic thin films. Growth
by segregation-driven processes is the predominant self-organizing mechanism for
two-dimensional TiB2.4 and three-dimensional TiN–TiB2 nanostructures. On the
other hand, growth of Ti 0.34 Al 0.66 N and Ti(N,B) is the result of a supersaturated
TiN-based phase formation, which tends to decompose into its stable constituents
via formation of nm-sized domains during post-deposition annealing (Mayrhofer
et al., 2006).
Fox-Rabinovich (2013) describes application of adaptive coatings that enable a
tribo-system to shift to a milder wear mode due to formation of protective/lubricious tribo-films during operation as a result of interaction with the external environment. Cutting and stamping tools can be considered as heavy loaded tribo-systems
(HLTS), working under severe conditions of high temperature and stresses with
intensive wear rates. Under severe frictional conditions, irreversible thermodynamic
and self-organization phenomena take place that may be used as an efficient protection of a friction surface. Hard plasma vapor deposited coatings are best suited
for this application. The self-organizing phenomenon is characterized by formation
Protection and Restoration
the dispersed phase maintained in a suspended state or transported to the cathode.
Electric current passing through the suspension forms a coating on the surface of a
restored component. According to the authors, CGC can solve three main problems:
1. Application of metal coating to a worn surface during recovery of parts and
their hardening
2. Application of metal and other coatings to protect part surfaces from
corrosion
3. Application of protective and decorative coatings
In terms of reliability and durability of repaired vehicle parts, the first task is the
most important. Analysis of car parts coming to reparation shows that wear is
mostly below 0.1–0.3 mm, which makes coating more economically effective than
replacement of a worn part, especially when the parts are made of expensive alloy
steels. Application of powders based on tungsten carbide with a particle size below
1 μm, produced by electro-erosion dispersion from waste-sintered hard alloys as
a dispersed phase of composite galvanic coatings based on iron during restoration
and hardening of car parts, is possible. The resulting micro-hardness was close to
that of the original component, while relative wear resistance of the obtained composite galvanic coatings was increased compared to simple iron galvanic coatings
(Semenikhin et al., 2020). It is noteworthy that not only waste materials are reused
and worn parts repaired at reduced costs, but also life of repaired parts is increased.
Mayrhofer et al. (2005) point out that nanostructures have attracted increasing
interest in modern development of hard coatings for wear-resistant applications.
There is a direct relation between hardness and nanostructure, because hardness of
a material is determined by resistance to bond distortion and dislocation formation
and motion, which in turn depend on the amount and constitution of obstacles inside
the material structure. Based on TiB 2.4 , TiN–TiB 2 , Ti 0.34 Al 0.66 N, and Ti(N,B) as
model-coatings, the authors demonstrate development of self-organized nanostructures and their influence on mechanical properties of ceramic thin films. Growth
by segregation-driven processes is the predominant self-organizing mechanism for
two-dimensional TiB2.4 and three-dimensional TiN–TiB2 nanostructures. On the
other hand, growth of Ti 0.34 Al 0.66 N and Ti(N,B) is the result of a supersaturated
TiN-based phase formation, which tends to decompose into its stable constituents
via formation of nm-sized domains during post-deposition annealing (Mayrhofer
et al., 2006).
Fox-Rabinovich (2013) describes application of adaptive coatings that enable a
tribo-system to shift to a milder wear mode due to formation of protective/lubricious tribo-films during operation as a result of interaction with the external environment. Cutting and stamping tools can be considered as heavy loaded tribo-systems
(HLTS), working under severe conditions of high temperature and stresses with
intensive wear rates. Under severe frictional conditions, irreversible thermodynamic
and self-organization phenomena take place that may be used as an efficient protection of a friction surface. Hard plasma vapor deposited coatings are best suited
for this application. The self-organizing phenomenon is characterized by formation