Abstract
Plasma-sprayed composite coatings of Cr2O3-MoO3 were studied to identify their microstructure and to understand the influence of molybdenum oxide composition in the coatings on their tribological behavior. Cr2O3-MoO3 composite powders and Cr2O3 powders were fabricated using a spray-drying method and plasma-sprayed coatings of these powders were produced to evaluate their tribological performance. Wear tests were conducted with a reciprocating motion at room temperature and 450 °C under dry sliding condition. Measurement of friction coefficient was made in association with the sliding cycle. The physical characteristics of surfaces were investigated by scanning electron microscopy and chemical composition of the coating surfaces was analyzed using a X-ray photoelectron spectrometer and a transmission electron microscope (TEM). The study showed that the microhardness of coatings containing MoO3 were higher than that composed of Cr2O3 alone. The result of TEM analysis indicated that chromium/molybdenum was precipitated in the grain and grain boundary. The friction coefficients of the MoO3 -added coatings were lower than that without MoO3 addition at both test temperatures. However, the addition of MoO3 in the Cr2O3 coatings did not significantly improve the wear performance of the coatings at both test temperatures. Dispersed smooth films were formed in the worn surface for all coatings. These wear protecting layers, formed by plastic deformation of adhered and compacted debris particles to the surface, strongly influence the friction of the coatings as already observed by the authors with different plasmasprayed coatings. The chemical composition of these films varied depending on the test temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 413-421 |
| Number of pages | 9 |
| Journal | Surface and Coatings Technology |
| Volume | 163-164 |
| DOIs | |
| Publication status | Published - 2003 Jan 30 |
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Keywords
- Friction and wear
- Plasma-sprayed CrO-MoO composite coatings
- Surface films
- Transmission electron microscopy
- X-ray photo electron spectroscopy
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Condensed Matter Physics
- Surfaces and Interfaces
Cite this
Microstructure and tribological properties of plasma-sprayed chromium oxide - molybdenum oxide compostie coatings. / Lyo, In Woong; Ahn, Hyo Sok; Lim, Dae-Soon.
In: Surface and Coatings Technology, Vol. 163-164, 30.01.2003, p. 413-421.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Microstructure and tribological properties of plasma-sprayed chromium oxide - molybdenum oxide compostie coatings
AU - Lyo, In Woong
AU - Ahn, Hyo Sok
AU - Lim, Dae-Soon
PY - 2003/1/30
Y1 - 2003/1/30
N2 - Plasma-sprayed composite coatings of Cr2O3-MoO3 were studied to identify their microstructure and to understand the influence of molybdenum oxide composition in the coatings on their tribological behavior. Cr2O3-MoO3 composite powders and Cr2O3 powders were fabricated using a spray-drying method and plasma-sprayed coatings of these powders were produced to evaluate their tribological performance. Wear tests were conducted with a reciprocating motion at room temperature and 450 °C under dry sliding condition. Measurement of friction coefficient was made in association with the sliding cycle. The physical characteristics of surfaces were investigated by scanning electron microscopy and chemical composition of the coating surfaces was analyzed using a X-ray photoelectron spectrometer and a transmission electron microscope (TEM). The study showed that the microhardness of coatings containing MoO3 were higher than that composed of Cr2O3 alone. The result of TEM analysis indicated that chromium/molybdenum was precipitated in the grain and grain boundary. The friction coefficients of the MoO3 -added coatings were lower than that without MoO3 addition at both test temperatures. However, the addition of MoO3 in the Cr2O3 coatings did not significantly improve the wear performance of the coatings at both test temperatures. Dispersed smooth films were formed in the worn surface for all coatings. These wear protecting layers, formed by plastic deformation of adhered and compacted debris particles to the surface, strongly influence the friction of the coatings as already observed by the authors with different plasmasprayed coatings. The chemical composition of these films varied depending on the test temperature.
AB - Plasma-sprayed composite coatings of Cr2O3-MoO3 were studied to identify their microstructure and to understand the influence of molybdenum oxide composition in the coatings on their tribological behavior. Cr2O3-MoO3 composite powders and Cr2O3 powders were fabricated using a spray-drying method and plasma-sprayed coatings of these powders were produced to evaluate their tribological performance. Wear tests were conducted with a reciprocating motion at room temperature and 450 °C under dry sliding condition. Measurement of friction coefficient was made in association with the sliding cycle. The physical characteristics of surfaces were investigated by scanning electron microscopy and chemical composition of the coating surfaces was analyzed using a X-ray photoelectron spectrometer and a transmission electron microscope (TEM). The study showed that the microhardness of coatings containing MoO3 were higher than that composed of Cr2O3 alone. The result of TEM analysis indicated that chromium/molybdenum was precipitated in the grain and grain boundary. The friction coefficients of the MoO3 -added coatings were lower than that without MoO3 addition at both test temperatures. However, the addition of MoO3 in the Cr2O3 coatings did not significantly improve the wear performance of the coatings at both test temperatures. Dispersed smooth films were formed in the worn surface for all coatings. These wear protecting layers, formed by plastic deformation of adhered and compacted debris particles to the surface, strongly influence the friction of the coatings as already observed by the authors with different plasmasprayed coatings. The chemical composition of these films varied depending on the test temperature.
KW - Friction and wear
KW - Plasma-sprayed CrO-MoO composite coatings
KW - Surface films
KW - Transmission electron microscopy
KW - X-ray photo electron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=0037472676&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037472676&partnerID=8YFLogxK
U2 - 10.1016/S0257-8972(02)00613-8
DO - 10.1016/S0257-8972(02)00613-8
M3 - Article
AN - SCOPUS:0037472676
VL - 163-164
SP - 413
EP - 421
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
ER -