Lyo, IW Ahn, HS Lim, DS 2024-01-21T09:33:21Z 2024-01-21T09:33:21Z 2022-01-10 2003-01-30 0257-8972 https://pubs.kist.re.kr/handle/201004/138902 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 degreesC 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 plasma-sprayed coatings. The chemical composition of these films varied depending on the test temperature. (C) 2002 Elsevier Science B.V. All rights reserved. English ELSEVIER SCIENCE SA DIESEL-ENGINES BEHAVIOR FILMS MO Microstructure and tribological properties of plasma-sprayed chromium oxide-molybdenum oxide composite coatings Article 10.1016/S0257-8972(02)00613-8 1 SURFACE & COATINGS TECHNOLOGY, v.163, pp.413 - 421 SURFACE & COATINGS TECHNOLOGY 163 413 421 scie scopus 000180450700064 2-s2.0-0037472676 Materials Science, Coatings & Films Physics, Applied Materials Science Physics Article; Proceedings Paper DIESEL-ENGINES BEHAVIOR FILMS MO plasma-sprayed Cr2O3-MoO3 composite coatings friction and wear surface films transmission electron microscopy X-ray photoelectron spectroscopy