Sliding Wear Behavior of HVOF-sprayed Cr3C2–NiCr/CeO2 Composite Coatings at Elevated Temperature up to 800 °C

Abstract

Four types of Cr 3 C 2 -NiCr coatings containing different fractions of CeO 2 additive were deposited using high velocity oxy-fuel spraying. Hardness tester, X-ray diffractometer, contact surface profiler, and scanning electron microscope equipped with energy dispersive spectrometer were employed to characterize the microhardness, phase composition, surface roughness, and microstructure of as-sprayed coatings. At the same time, the friction and wear behavior of the as-sprayed coatings sliding against Si 3 N 4 ball at room temperature and elevated temperature of 400 or 800°C under unlubricated condition was evaluated using an oscillating friction and wear tester. The worn surfaces of the composite coatings and Si 3 N 4 counterpart balls were analyzed by means of scanning electron microscopy, X-ray diffraction, and three dimensional non-contact surface profiler. The friction and wear mechanisms of the coatings with and without CeO 2 additive were comparatively discussed. Results show that the composite coatings doped with CeO 2 had better wear-resistance than that without CeO 2 , and the coating containing 4 wt% CeO 2 showed the best wear-resistant property. The improved wear-resistant properties of the composite coatings doped with CeO 2 were attributed to the refined microstructure and improved mechanical properties induced by CeO 2 .

Sliding and abrasive wear behaviour of HVOF- and HVAF-sprayed Cr3C2–NiCr hardmetal coatings

“…The dry sliding wear rates of the Cr 3 C 2 -NiCr coatings produced at room temperature (Fig. 8B) are around or slightly below 10 À 5 mm 3 /(Nm), which is consistent with the values generally reported in the literature for such coatings tested under similar conditions [29,30,66]. Quite comparable wear rates were also found by some of the present authors both in dry sliding against Al 2 O 3 counterbodies and in self-mated contact conditions, using a specially designed ball-on-disk tribometer [32,33].…”

“…At 400°C, the wear rates of all Cr 3 C 2 -NiCr coatings are comprised between 5x10 À 5 mm 3 /(Nm) and 10 À 4 mm 3 /(Nm) (Fig. 8C), consistent with the results of various oscillating [66] and rotating [32,33] ball-on-disk tests performed against a variety of hard counterbodies (including Si 3 N 4 [66] and Al 2 O 3 [32]) as well as in self-mated conditions [32,33]. The values are approximately one order of magnitude higher than those at room temperature (compare to Fig.…”

Synthesis and Tribological Properties of Stearic Acid-Modified Anatase (TiO2) Nanoparticles

“…Especially, in the field of tribology, many kinds of inorganic nanoparticles have been successfully used in lubricating oils and greases [5][6][7], bonded solid lubricating films [8,9], and thermal-sprayed anti-wear composite coatings [10,11] etc. to solve friction and wear problems.…”

Microstructure and wear properties of Al 2 O 3 -CeO 2 /Ni-base alloy composite coatings on aluminum alloys by plasma spray

“…Atoms Ce, with big diameter and high surface activity, can reduce surface tension and interface energy per unit area [23,24]. According to Eq.…”