| Title |
Structural and tribological properties of ceramic coatings deposited by plasma spraying / |
| Authors |
Bastakys, L ; Mathew, J.S ; Marcinauskas, L ; Aikas, M ; Tučkutė, S |
| ISBN |
9786090705575 |
| Full Text |
|
| Is Part of |
NBCM 2020: international conference on nanostructured bioceramic materials, 1-3 December 2020, Vilnius, Vilnius University: conference book.. Vilnius : Vilnius Univerity Press, 2020. p. 20.. ISBN 9786090705575 |
| Keywords [eng] |
structural and tribological properties ; ceramic coatings ; plasma spraying |
| Abstract [eng] |
Alumina ceramic coatings show resistance to wear, high strength, and hardness. Al2O3 coatings are also resistant to corrosion and high temperatures [1-2]. Due to the ability to reach high melting point of various ceramic materials, plasma spraying has been widely used as a deposition technique for ceramic coating formation. It has been reported that additions of graphene or chromia can further improve alumina coating properties [3-5]. Aim of this work was to showcase the ability to form coatings made from different kinds of powder compositions using plasma spraying technology as well as to compare alumina, alumina composite and chromia coating’s structural and tribological properties. Using atmospheric plasma spraying alumina (Al2O3), alumina-chromia (Al2O3-10 wt.% Cr2O3), alumina-graphite (Al2O3-10 wt.%C) and chromia (Cr2O3) coatings were deposited on P265GH steel substrate. Air and hydrogen mixture was used to create plasma jet. The surface morphology was investigated using scanning electron microscopy (SEM) Hitachi S-3400N. The elemental composition of the deposited coatings was determined by energy dispersive spectroscopy (EDS) using Bruker Quad 5040 spectrometer. The crystallography of the coatings was investigated by X-ray diffraction (XRD). Friction coefficient was measured using a CETR-UMT-2 ball-on-flat tribometer. Surface morphology investigation results revealed that a higher degree of melting occurred for alumina-based coatings. EDS results showed that 10 wt.% graphite addition to alumina powders resulted in only ~1.9 wt.% to be present on the coating surface. Meanwhile, the concentration of chromium was ~3.9 wt.% when alumina-chromia powders were used. XRD patterns indicated that alumina-based coatings consisted of α-Al2O3, β-Al2O3 and γ-Al2O3 phases. The XRD pattern of alumina-graphite coating had an additional (002) graphite peak. For alumina-chromia coating, XRD patterns revealed eskolaite (Cr2O3) peaks and relatively higher intensities of α-Al2O3 phase peaks. The tribological tests indicated that the friction coefficient (COF) of Al2O3 coating was ~0.55. The COF of chromia coating was similar (~0.56), meanwhile, a small addition of graphite or chromia into alumina powders resulted in a slight increase of COF values. The as-sprayed coatings exhibited superior wear-resistance and the specific wear rates were reduced up to 10 times compared to steel. |
| Published |
Vilnius : Vilnius Univerity Press, 2020 |
| Type |
Conference paper |
| Language |
English |
| Publication date |
2020 |
| CC license |
|
