119
Protection and Restoration
(2021) fabricated metallic glass coating layers out of new Fe 46.8 -Mo 30.6 -Cr 16.6 -C 4.3 -B 1.7
powders via VPS. Despite presence of splat particles and minor unmelted powders,
all the alloying elements in the VPS material were evenly distributed throughout
the coating layer and showed superior corrosion resistance compared to the similar
material fabricated with APS method. Unlike APS, the VPS process uses a lowpressure argon atmosphere that inhibits oxidation of the coating layer, while the high
velocity of the molten droplets facilitates formation of highly dense coatings (Kim
et al., 2020). Henao et al. (2019) describe application of VPS to produce bioactive
glass coatings on Ti-6Al-4V substrates. Deposition of high-quality coatings with
good adherence and with very little or even no oxidation, high homogeneity, and
without any modification of the initial bioactive glass composition was possible.
VPS systems constitute separate devices of complex functions which are able to
(Romanov, 2010):
• Generate proper vacuum
• Evaporate or spray a coating material
• Control sputtering parameters and thus properties of obtained films
• Transport components before and after processing
• Ensure proper power supply
From the design perspective, a typical VPS unit consists of the following subunits
(Gushcha, 2009):
• Spray chamber, where the material is sputtered on the substrate
• Sources of evaporated or sprayed materials with power supply and control
systems
• Pumping and pressure-distribution systems ensuring proper vacuum and
gas flow, including pumps, valves, traps, flanges and covers, as well as measurement devices for vacuum and gas flow rates
• Main power supply and safety switches for all the subunits
• Control systems for sputtering dosing including sensors, actuators, and
controllers, so that proper sputtering rate and temperatures ensure desired
thickness and properties of the coating
• Transporting devices to place components in the spray chamber with exact
positioning, as well as to change their position during the process when a
multilayer coating is produced
• Additional equipment such as screens and dampers, manipulators, hydraulic and pneumatic drives, gas cleaning devices, etc.
For practical realization of the plasma spraying process, integrated technological
systems are developed, enabling both modeling and experimental study (Kundas and
Ilyuschenko, 2002). The proposed system provided simulation of the main plasma
spraying process stages, including heating and acceleration of particles, heat transfer, coating structure formation, and stress–strain state in a coating–substrate system, but also experimental measurement of the main characteristics of the process
Protection and Restoration
(2021) fabricated metallic glass coating layers out of new Fe 46.8 -Mo 30.6 -Cr 16.6 -C 4.3 -B 1.7
powders via VPS. Despite presence of splat particles and minor unmelted powders,
all the alloying elements in the VPS material were evenly distributed throughout
the coating layer and showed superior corrosion resistance compared to the similar
material fabricated with APS method. Unlike APS, the VPS process uses a lowpressure argon atmosphere that inhibits oxidation of the coating layer, while the high
velocity of the molten droplets facilitates formation of highly dense coatings (Kim
et al., 2020). Henao et al. (2019) describe application of VPS to produce bioactive
glass coatings on Ti-6Al-4V substrates. Deposition of high-quality coatings with
good adherence and with very little or even no oxidation, high homogeneity, and
without any modification of the initial bioactive glass composition was possible.
VPS systems constitute separate devices of complex functions which are able to
(Romanov, 2010):
• Generate proper vacuum
• Evaporate or spray a coating material
• Control sputtering parameters and thus properties of obtained films
• Transport components before and after processing
• Ensure proper power supply
From the design perspective, a typical VPS unit consists of the following subunits
(Gushcha, 2009):
• Spray chamber, where the material is sputtered on the substrate
• Sources of evaporated or sprayed materials with power supply and control
systems
• Pumping and pressure-distribution systems ensuring proper vacuum and
gas flow, including pumps, valves, traps, flanges and covers, as well as measurement devices for vacuum and gas flow rates
• Main power supply and safety switches for all the subunits
• Control systems for sputtering dosing including sensors, actuators, and
controllers, so that proper sputtering rate and temperatures ensure desired
thickness and properties of the coating
• Transporting devices to place components in the spray chamber with exact
positioning, as well as to change their position during the process when a
multilayer coating is produced
• Additional equipment such as screens and dampers, manipulators, hydraulic and pneumatic drives, gas cleaning devices, etc.
For practical realization of the plasma spraying process, integrated technological
systems are developed, enabling both modeling and experimental study (Kundas and
Ilyuschenko, 2002). The proposed system provided simulation of the main plasma
spraying process stages, including heating and acceleration of particles, heat transfer, coating structure formation, and stress–strain state in a coating–substrate system, but also experimental measurement of the main characteristics of the process