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Vacuum-plasma, plasma methods of surface modification of engineering parts Victor Kazachenko, PhD, Associate professor Laboratory of Surface Physics and Thin Films, Belarusian State University of Transport, Gomel 246653, Belarus, kvp_@mail.ru. Modification of engineering parts. - PowerPoint PPT Presentation
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Vacuum-plasma, plasma methods of surface modification of engineering
parts
Victor Kazachenko, PhD, Associate professorLaboratory of Surface Physics and Thin Films,
Belarusian State University of Transport, Gomel 246653, Belarus, kvp_@mail.ru
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Modification of engineering parts
• PART 1Deposition of nanostructured TiN+C coatings from pulsed cathodic-arc plasma discharge in vacuum
• PART 2Electrofriction Discharge Hardening (EDH) of engineering parts operating under the conditions of abrasive wear
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PART 1 Nanostructured TiN+C coatings
3
Pulsed cathodic arc carbon plasma source
• The cathode is made of titanium.• The arc ignition system and additional anode are made of graphite.• The pressure of nitrogen is about 6·10-3 Pa during the coating synthesis.
4
Structure of TiN+C coating, synthesized by pulsed-arc method
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2 m
SEM image of TiN+C coating
5 m
SEM image of TiN coating
AFM topography AFM phase
AFM 3D
Raman spectroscopy study of TiN+C coatings
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Carbon
Aco
ustic
al m
odes
G m
ode
TiN
D m
ode
Opt
ical
m
odes
Tribotechnical properties of TiN-C coatings
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0 50 100 150 2000,0
0,2
0,4
0,6 Initial contact pressure:TiN
580 MPa 660 MPa
TiN+C 660 MPa 725 MPa
Coe
ffitie
nt o
f fric
tion
Cycle
plunger pairs of high-pressure fuel pumps
measuring tools
simmerings
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Applications
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PART 2Electrofriction Discharge Hardening
(EDH)
Electrofriction Discharge Hardening Scheme
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1 - rotating tool, 2 - water, 3 - sample, 4 - zone of discharge
The setups allow hardeningflat surfaces
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Experimental Setup Parameters Value
Maximum discharge power, kW 7,5
Tool rotation frequency, min-1 1 - 200
Linear speed, m/min 0.05 - 10
The size of the processed part, mmmaximum lengthmaximum widthmaximum depth
50022550
Structure and microhardness with thickness of the modified layer of 65Г steel (65Mn)
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EDH current - 250 A
The distance from the surface, mm
HV
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Structure and microhardness with thickness of the modified layer of 35ХГСА steel (35CrMnSi)
EDH current - 200 A
HV
The distance from the surface, mm
Structure of surface layers of ВЧ100 cast iron (ISO 900-2)
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100x 500x
Quasi ledeburiteMicrohardness – up to 1000 HV
Graphitic inclusions are preservedMartensite and residual austeniteMicrohardness – 800-850 HV
Gradual transition to the pristinecast iron structure
Hardened chisel-like plowshares (“Kverneland”)
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Hardened cartridge of cutters for rock
fracturing
The lifetime of the hardened plowshares increased by 76 ha in sandy loam soils
Hardened zone
Hardened zone
Conclusion• In comparison with conventional TiN coatings, the
nanocomposite layers of TiN containing carbon demonstrate lower roughness, less defects, significantly lower coefficient of friction and high wear resistance
• Electrofriction discharge hardening (EDH) method allows hardening layers up to 3.5 mm deep without significant heating of the part. The method does not use expensive welding materials. Hardened layers exhibit the abrasive wear rate up to 5 times lower than the pristine material. The EDH is characterized by high productivity, low-cost equipment and easy automation. The EDH is suitable for hardening the soil processing and rock fracturing tools in agriculture and mining machinery.
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Thank You!
We are looking forward to successful cooperation.
Victor Kazachenko, PhD, Associate professorLaboratory of Surface Physics and Thin Films,
Belarusian State University of Transport, Gomel 246653, Belarus,
kvp_@mail.ru
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