Tribological and mechanical behaviour of Cr 3 C 2 –NiCr thermally sprayed coatings after prolonged aging

Gariboldi, Elisabetta; Rovatti, Ludovica; Lecis, N.; Mondora, L.; Mondora, G. A.

doi:10.1016/j.surfcoat.2016.07.087

Cited by 43 publications

(16 citation statements)

References 19 publications

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“…Therefore, the main wear mechanisms of the Cr 3 C 2 coating are abrasion and adhesion. 17 In addition to the pores created during the preparation of the WC coating, there are a small number of adhesive pits and wrinkles (as shown in Figure 14(c)), and the number of adhesive pits increases significantly as the load increases to 50 N (as shown in Figure 14(d)). The hardness of the WC coating is relatively high, and the surface roughness is low.…”

Section: Resultsmentioning

confidence: 99%

Effect of wear-resistant coatings on the comprehensive performance of finger seal

Zhang

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part J:

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Finger seals provide favourable flexible dynamic performance and a low level of leakage that is less than that of brush seals and graphite seals. However, the hysteresis caused by the friction between different finger slices or between the finger slice and the back plate strongly affects the working stability. In addition, the wear properties between the finger feet and rotor runway can adversely affect the working stability. Based on the tribological mechanism, wear-resistant coatings can provide a satisfactory solution to these problems. For this purpose, the simulations of finger seal are first performed in ANSYS to verify that good contact surface friction performance can effectively improve the efficiency of finger seal. Then we evaluated the friction performance of WC, Cr3C2, and PTFE coatings using a pin-on-disk tribometer. The results showed that the wear-resistant coatings generally exhibited better wear resistance than the substrate material under various load conditions (correspond to the bench test PV of finger seal). The friction coefficient of the 40CrNiMoA substrate was 0.65, while the friction coefficients of WC, Cr3C2, and PTFE coatings were 0.22, 0.27, and 0.13, respectively, corresponding to 33.8%, 41.5%, and 20% of the friction coefficient of the 40CrNiMoA substrate. The friction coefficient of the PTFE coating was the lowest due to its self-lubricating property and showed a long service life under low loads; thus, this coating offers a promising solution to reduce the friction-caused hysteresis on a finger seal. Under loads of 20 N and 30 N, the service life of the WC coating was much longer than that of the Cr3C2 coating. Even at a load of 50 N, the service life of the WC coating was 4.3 times that of the Cr3C2 coating. The wear-resistant WC coating has strong application prospects in improving the service life of finger seals.

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Section: Resultsmentioning

confidence: 99%

Effect of wear-resistant coatings on the comprehensive performance of finger seal

Zhang

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part J:

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“…In this aging condition, the wear rate was about 2 × 10 −7 mm 3 /(N•m), showing a value about 80% lower than that obtained in the as-coated condition. Moreover, the improved tribological resistance of the aged Cr 3 C 2 -25NiCr coatings results from the high hardness and from the formation of stable and protective oxides during previous aging [90]. Dry particle abrasion involves coarse abrasive grooving and pull-out of coating fragments, which are closely related to the mechanical properties reflecting long-range inter-lamellar cohesion (such as fracture toughness and elastic modulus), and partly related to microhardness, which depends on intra-lamellar cohesion.…”

Section: Wear Resistance Of Cr 3 C 2 -Nicr and Wc-based Nanostructurementioning

confidence: 99%

“…The nanocrystalline particle melts with relative ease, leading to high density and low porosity with unmelted or partially melted coarse particles embedded within the matrix. The coatings with such structures are likely to be hard, ductile, and wear resistant, and heat treatment of the nanostructured coating may also enhance the mechanical properties, wear, erosion, and corrosion behavior [21,47,83,90,[92][93][94].…”

Section: Wear Resistance Of Cr 3 C 2 -Nicr and Wc-based Nanostructurementioning

confidence: 99%

Nanocrystalline Cermet Coatings for Erosion–Corrosion Protection

et al. 2019

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The processing techniques, microstructural characteristics, and erosion corrosion behaviour of Cr3C2–NiCr and tungsten carbide (WC)-based cermet coatings are reviewed in this work. Conventional and nanocrystalline Cr3C2–NiCr and WC-based cermet coatings are generally synthesized using thermal spray technique. The wear, erosion, and corrosion protection ability of conventional and nanocermet coatings are compared based on available literature. In Cr3C2–NiCr coatings, the corrosion resistance is offered by NiCr metal matrix while the wear resistance is provided by the carbide ceramic phase, making it suitable for erosion–corrosion protection. The nanocrystalline cermet coatings exhibits better erosion–corrosion resistance as compared to the conventional coatings. The nanocrystalline coatings reduces the erosion–corrosion rate significantly compared to conventional coatings. It is attributed to the presence of the protective NiCr metallic binder that allows easier and faster re-passivation when the coating is subjected to wear and the fine-grain structure with homogeneous distribution of the skeleton network of hard carbide phases. In addition, corrosion-accelerated erosion dominates the reaction mechanism of erosion–corrosion and, therefore, higher hardness, strength, and better wear resistance of nanocermet coating along with its faster repassivation kinetics accounts for improved corrosion resistance as compared to conventional coatings.

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“…Mechanical wear pairs are highly required to be used in severe temperature and corrosion environments such as aircraft, aerospace, automobiles, and various other fields . Ceramic coatings have been used to protect the surfaces of components due to their excellent properties such as high temperature resistance, abrasion resistance, and corrosion resistance . However, high wear rate at harsh working temperatures is still one of the major failure modes of the coatings, which will significantly reduce the service life of the coatings and base material .…”

Section: Introductionmentioning

confidence: 99%

Tribological behavior studies of chemically bonded phosphate ceramic coatings reinforced with modified multi‐walled carbon nanotubes (MWCNTs)

Rongli

Bian

Xu³

et al. 2019

Int J Applied Ceramic Tech

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To improve the wear resistance of the chemically bonded phosphate ceramic coatings, MWCNTs are selected as the reinforcement after the modification. The high temperature wear experiment is carried out to investigate the wear behavior of the coatings with different temperatures. The results suggest that, when the temperature is below 500℃, MWCNTs can decrease friction coefficient, and the lowest friction coefficient is about 0.28, but MWCNTs lose the lubricant function at 500℃ and the friction coefficient keeps at the level of ~ 0.68. In addition, the wear resistance of coatings is improved with the introduction of MWCNTs at 100℃ and 300℃ (the wear rate is below 15X10 -3 mm 3 /Nm), but keeps similar level at 500℃ (the wear rate is ~ 22 × 10 −3 mm 3 /Nm). Besides, the wear mechanism of the coatings reinforced by MWCNTs is also investigated based on the wear behavior and microstructural characterizations. MWCNTs improve the fracture toughness by preventing the crack generation and forming the bridge when crack occurs, which leads to smooth wear tracks and good wear resistance of coatings. The coatings with MWCNTs achieve poor wear resistance at 500℃ because MWCNTs lose their strength and resistance to fatigue by oxidizing. K E Y W O R D Sceramic coatings, high temperature, MWCNTs, wear performance

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Tribological and mechanical behaviour of Cr 3 C 2 –NiCr thermally sprayed coatings after prolonged aging

Cited by 43 publications

References 19 publications

Effect of wear-resistant coatings on the comprehensive performance of finger seal

Effect of wear-resistant coatings on the comprehensive performance of finger seal

Nanocrystalline Cermet Coatings for Erosion–Corrosion Protection

Tribological behavior studies of chemically bonded phosphate ceramic coatings reinforced with modified multi‐walled carbon nanotubes (MWCNTs)

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