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Tribological performance of Graphene/Carbon nanotube hybrid reinforced Al2O3 composites.

Yazdani B, Xu F, Ahmad I, Hou X, Xia Y, Zhu Y - Sci Rep (2015)

Bottom Line: Benchmarked against the pure Al2O3, the composite reinforced with a 0.5 wt% GNP exhibited a 23% reduction in the friction coefficient along with a promising 70% wear rate reduction, and a hybrid reinforcement consisting of 0.3 wt.% GNPs + 1 wt.% CNTs resulted in even better performance, with a 86% reduction in the wear rate.The wear mechanisms for the composites were analysed based on the mechanical properties, brittleness index and microstructural characterizations.GNPs played the important role in the formation of a tribofilm on the worn surface by exfoliation; whereas CNTs contributed to the improvement in fracture toughness and prevented the grains from being pulled out during the tribological test.

View Article: PubMed Central - PubMed

Affiliation: College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK.

ABSTRACT
Tribological performance of the hot-pressed pure Al2O3 and its composites containing various hybrid contents of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) were investigated under different loading conditions using the ball-on-disc method. Benchmarked against the pure Al2O3, the composite reinforced with a 0.5 wt% GNP exhibited a 23% reduction in the friction coefficient along with a promising 70% wear rate reduction, and a hybrid reinforcement consisting of 0.3 wt.% GNPs + 1 wt.% CNTs resulted in even better performance, with a 86% reduction in the wear rate. The extent of damage to the reinforcement phases caused during wear was studied using Raman spectroscopy. The wear mechanisms for the composites were analysed based on the mechanical properties, brittleness index and microstructural characterizations. The excellent coordination between GNPs and CNTs contributed to the excellent wear resistance property in the hybrid GNT-reinforced composites. GNPs played the important role in the formation of a tribofilm on the worn surface by exfoliation; whereas CNTs contributed to the improvement in fracture toughness and prevented the grains from being pulled out during the tribological test.

No MeSH data available.


Related in: MedlinePlus

Wear track profiles (a) and wear rates (b) of the pure Al2O3 and Al2O3-GNP composites.
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f6: Wear track profiles (a) and wear rates (b) of the pure Al2O3 and Al2O3-GNP composites.

Mentions: The wear track profiles of pure Al2O3 and Al2O3-GNP composites are shown in Fig. 6a, and the wear rates were calculated uisng equation (3) and plotted in Fig. 6b. According to the wear track profile (Fig. 6a), the GNP contents played a critical role in the tribological properties. The worn volume decreased with increased GNP contents, up to 2 wt%, however adding 5 wt% GNPs deteriorated the wear resistant property and drastically increased the worn volume (Fig. 6a), and the wear rate (Fig. 6b). It is clear that adding 0.5 wt% GNPs into the Al2O3 matrix led to the biggest improvement in the wear resistance, resulting in over 70% reduction in the wear rate, benchmarked against the pure Al2O3 (Fig. 6b). Such a huge wear resistant improvement in the S0.5-0 also matched well with the previously confirmed lowest COF of S0.5-0 amongst other GNP single phase reinforced composites (Fig. 3a), and the lowest wight loss (Fig. 3b).


Tribological performance of Graphene/Carbon nanotube hybrid reinforced Al2O3 composites.

Yazdani B, Xu F, Ahmad I, Hou X, Xia Y, Zhu Y - Sci Rep (2015)

Wear track profiles (a) and wear rates (b) of the pure Al2O3 and Al2O3-GNP composites.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477330&req=5

f6: Wear track profiles (a) and wear rates (b) of the pure Al2O3 and Al2O3-GNP composites.
Mentions: The wear track profiles of pure Al2O3 and Al2O3-GNP composites are shown in Fig. 6a, and the wear rates were calculated uisng equation (3) and plotted in Fig. 6b. According to the wear track profile (Fig. 6a), the GNP contents played a critical role in the tribological properties. The worn volume decreased with increased GNP contents, up to 2 wt%, however adding 5 wt% GNPs deteriorated the wear resistant property and drastically increased the worn volume (Fig. 6a), and the wear rate (Fig. 6b). It is clear that adding 0.5 wt% GNPs into the Al2O3 matrix led to the biggest improvement in the wear resistance, resulting in over 70% reduction in the wear rate, benchmarked against the pure Al2O3 (Fig. 6b). Such a huge wear resistant improvement in the S0.5-0 also matched well with the previously confirmed lowest COF of S0.5-0 amongst other GNP single phase reinforced composites (Fig. 3a), and the lowest wight loss (Fig. 3b).

Bottom Line: Benchmarked against the pure Al2O3, the composite reinforced with a 0.5 wt% GNP exhibited a 23% reduction in the friction coefficient along with a promising 70% wear rate reduction, and a hybrid reinforcement consisting of 0.3 wt.% GNPs + 1 wt.% CNTs resulted in even better performance, with a 86% reduction in the wear rate.The wear mechanisms for the composites were analysed based on the mechanical properties, brittleness index and microstructural characterizations.GNPs played the important role in the formation of a tribofilm on the worn surface by exfoliation; whereas CNTs contributed to the improvement in fracture toughness and prevented the grains from being pulled out during the tribological test.

View Article: PubMed Central - PubMed

Affiliation: College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK.

ABSTRACT
Tribological performance of the hot-pressed pure Al2O3 and its composites containing various hybrid contents of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) were investigated under different loading conditions using the ball-on-disc method. Benchmarked against the pure Al2O3, the composite reinforced with a 0.5 wt% GNP exhibited a 23% reduction in the friction coefficient along with a promising 70% wear rate reduction, and a hybrid reinforcement consisting of 0.3 wt.% GNPs + 1 wt.% CNTs resulted in even better performance, with a 86% reduction in the wear rate. The extent of damage to the reinforcement phases caused during wear was studied using Raman spectroscopy. The wear mechanisms for the composites were analysed based on the mechanical properties, brittleness index and microstructural characterizations. The excellent coordination between GNPs and CNTs contributed to the excellent wear resistance property in the hybrid GNT-reinforced composites. GNPs played the important role in the formation of a tribofilm on the worn surface by exfoliation; whereas CNTs contributed to the improvement in fracture toughness and prevented the grains from being pulled out during the tribological test.

No MeSH data available.


Related in: MedlinePlus