Мardarevych R.S., Vуnar V.A., SlepkoR.T., Vasyliv Kh.B. Effect of thermal treatment on the tribocorrosion resistance of nickel-based galvanic coatings.

  • Р. С. Мардаревич
  • В. А. Винар
  • Р. Т. Слєпко
  • Х. Б. Василів
Keywords: nickel-based galvanic coatings, heat treatment, tribocorrosion, hydrogen, friction coefficient

Abstract

The tribocorrosion behavior of nickel-based galvanic coatings before and after thermal treatment has been investigated. The influence of hydrogenating on the tribotechnical characteristics of the coatings in a 0.5 M aqueous solution of sulfate acid has been studied.

Galvanic nickel coating of 50 ... 60 μm thickness was applied to samples in sulfate chloride electrolyte. Composite electrochemical nickel-boron coating (CPE) of a similar thickness was applied from a suspension of amorphous boron in a sulfate chloride electrolyte of nickel. The developed chemical composition of the bath, the parameters of electrolysis and the hydrodynamic modes of mixing the suspension provide electrodeposition of a high-quality composite nickel-boron layer with a homogeneous distribution of boron particles and their content in the nickel-matrix of 4.8 ... 5.3 mass%. Nickel-phosphorous coating was applied by the method of chemical precipitation from acidic electrolyte. Thickness of coating was 25 ... 28 mm and phosphorus content was 11 ... 12.5 mass%. Thermal treatment of samples with coatings was carried out by annealing in a vacuum furnace at 450°C for 1 hour. Samples from Ni-B CPE were additionally annealed at 900°C for 1 h.

Tribocorrosion studies of plates 50×40×5 mm with coatings were carried out according to the scheme of friction "plane-sphere" with the reciprocating displacement of contacting surfaces. The load on the indenter (Al2O3 ball, Ø9 mm) was 2 N. Material losses were determined by the width of the friction track.

It is established, that cathodic polarization reduces wear-resistance of coatings in 1,2 ... 2,3 times. An electrochemical composite Ni-B coating after annealing at 900°C forms a new heterogeneous structure. It consists of a solid nickel solution and Ni3B boride grains inclusions. High hardness and sufficient resistance to hydrogen determine the increased wear resistance of this composition compared with others. Hydrogenating of the Ni-P coating at the friction reduces wear by 2.1 times.

References

1. Kula P. Comparison of resistance to hydrogen wear on hardened surface layers. Wear. 1994. Vol. 178. P. 117-121.
2. Mardarevich R.S. Investigation of the electrodepositing process of nickel-boron based composite coatings. Vestnik Nats. Technical university "KhPI". 2005. No. 15. P. 107- 110.
3. Vynar V.A., Dovgunyk V.М., Student М.М. Methodical features of tribochorous researches. Physical-chemical mechanics of materials. 2010. No. 5. P. 59-64.
4. Kovensky I.M., Povetkin V.V., Venediktov N.L. Changing the protective and mechanical properties of electrolytic coatings during annealing. Protection of metals, 1992. T. 28, No. 3. P. 338-341.
5. Structure-phase transformation in electrochemical boron containing coatings by thermal treat¬ment /Pokhmurskii V., Mardarevych R., Wielage B., Pokhmurska H., Wank A. Ta¬gungsband zum 8. Werkstofftechnischen Kolloquium, Chemnitz. 2005. Band 22. P. 33-40.
6. Povetkin VV, Kovensky I.M., Ustinovschikov Yu.I. Structure and properties of electrolytic alloys. Moscow: Nauka, 1992. 255 p.
7. Spiridonov B.A., Gusev AL, Shalimov Yu.N. Hydrogenation of nickel coatings obtained by constant and impulse current. Alternative energy and ecology. 2007. No. 5 (49). P. 45-48.
8. Gorelik SS, Blanther MS Formation of vacancies at recrystallization. Izvestiya of the Academy of Sciences of the USSR. Metals. 1982. No. 2. P. 90-93.
9. Interaction of hydrogen with metals. Agaev VN, Becman AG, Burmistrova O.P. and others. M.: Nauka, 1987. 296 p.
Published
2018-10-31
How to Cite
Мардаревич, Р., Винар, В., Слєпко, Р., & Василів, Х. (2018). Мardarevych R.S., Vуnar V.A., SlepkoR.T., Vasyliv Kh.B. Effect of thermal treatment on the tribocorrosion resistance of nickel-based galvanic coatings. Problems of Tribology, 89(3), 6-10. Retrieved from https://tribology.khnu.km.ua/index.php/ProbTrib/article/view/674
Section
Articles

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