Tribological properties of silica–graphene nano-platelet composites

Porwal, Harshit; Tatarko, Peter; Saggar, Richa; Grasso, Salvatore; Mani, Mahesh Kumar; Dlouhý, Ivo; Dusza, Ján; Reece, Mike

doi:10.1016/j.ceramint.2014.04.046

Cited by 83 publications

(54 citation statements)

References 23 publications

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“…Graphene has also proven to be an excellent lubricant additive due to its two-dimensional layered structure. 9,[11][12][13][26][27][28][29] It has been shown that a small amount of graphene solution added to a steel surface displays a four-orderof-magnitude reduction in wear during sliding. The significance of graphene addition was also observed in the reduction in the COF by a factor of 6, which was attributed to a conformal protective graphene coating formation on the sliding steel surface.…”

Section: Introductionmentioning

confidence: 99%

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Zhangcheng¹,

NietoAndy²,

AgarwalArvind³

2016

Nanomaterials and Energy

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Graphene nanoplatelet (GNP)-reinforced aluminum oxide (Al 2 O 3 ) composites were sintered by spark plasma sintering in three different compositions (0, 0·5, 5 vol.% GNPs). To investigate the effects of graphene addition on the composites' wear resistance, ball-on-disk wear tests were conducted under very high normal load (40 N) by using a 3-mm-dia. ceramic counterface. Aluminum oxide-0·5 vol.% GNP exhibited 65% improvement in the wear resistance, while aluminum oxide-5 vol.% GNP displayed 53% poorer wear resistance as compared with aluminum oxide. The coefficient of friction was 0·45 for aluminum oxide-0·5 vol.% GNP, 0·40 for aluminum oxide-5 vol.% GNP and 0·60 for aluminum oxide. The highest wear resistance of aluminum oxide-0·5 vol.% GNP is attributed to formation of a continuous, protective and ultrathin graphene tribofilm on the wear surface. Tribofilm formation occurs due to the high shear forces induced by countersurface movement and localized heating, which causes GNP's delamination, overlap and welding together. In the case of aluminum oxide-5 vol.% GNP, poor dispersion and agglomeration of GNP results in a thick and discontinuous graphene tribofilm, which does not protect from the brittle fracture of aluminum oxide grains during wear.

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Section: Introductionmentioning

confidence: 99%

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Zhangcheng¹,

NietoAndy²,

AgarwalArvind³

2016

Nanomaterials and Energy

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“…The BNNSs appeared thicker in the nanocomposites due to overlap of BNNSs that occurred during the drying process of the composite slurry. This kind of overlapping has been reported for graphene in silica 36 and alumina 37 matrices as well. It was also noticed that the BNNSs were aligned in a direction perpendicular to the applied force during SPS.…”

Section: Resultsmentioning

confidence: 87%

Boron nitride nanosheets reinforced glass matrix composites

Saggar

Porwal

Tatarko

et al. 2015

Advances in Applied Ceramics

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The effect of reinforcing boron nitride nanosheets (BNNSs) on the mechanical properties of an amorphous borosilicate glass (BS) matrix was studied. The BNNSs were prepared using liquid exfoliation method and characterised by transmission electron microscopy, scanning electron microscopy and X-ray diffraction (XRD) analysis. The average length was ,0.5 mm, and thickness of the nanosheets was between 4 and 30 layers. These BNNSs were used to prepare BS-BNNS composite with different loading concentrations of 1, 2.5 and 5 mass-% (i.e. 1.395, 3.705 and 7.32 vol.-%). Spark plasma sintering (SPS) was used to densify these composites to avoid structural damages to the BNNSs and/or crystallisation within the composite sample during high temperature processing. The BNNSs were found to be evenly distributed in the composites matrix and were found to be aligned in an orientation perpendicular to the direction of the applied force in SPS. The mechanical properties including fracture toughness, flexural strength and elastic modulus were measured. Both fracture toughness and flexural strength increased linearly with increasing concentration of BNNSs in BS glass. There was an enhancement of ,45% in the fracture toughness (1.10 MPa.m 1/2 ) as well as flexural strength (118.82 MPa) with the addition of only 5 mass-% loading of BNNSs compared to BS glass (0.76 MPa.m 1/2 ; 82.16 MPa). The toughening mechanisms developed in the composites because of the reinforcement of BNNSs were thoroughly investigated.

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“…It should be noted that other authors have reported an improvement in the wear resistance of glass/ceramic nanocomposites with the addition of GNP. 30,37 Most of the works reported have used a ball on disc method to measure the wear resistance of these material for long sliding distances (w300 m) and various loads (1- 200 N). In the case of tribological properties measured using ball on disc methods, authors reported the formation of a tribofilm on surface of composites.…”

Section: Porwal Et Al Scratch Behaviour Of Graphene Alumina Nanocompmentioning

confidence: 99%

“…Porwal et al reported an improvement of *5.5 times in wear resistance for silica-GNP (5 vol.-%) composites. 30 The research so far has shown promising improvements in tribological properties with the addition of carbon nanofillers. It should be noted that there is little reported literature on the scratch resistance of ceramic nanocomposites, despite their promising tribological properties.…”

Section: Introductionmentioning

confidence: 99%

Scratch behaviour of graphene alumina nanocomposites

Porwal

Kašiarová

Tatarko

et al. 2015

Advances in Applied Ceramics

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The scratch resistance behaviour of alumina-graphene nanoplatelet (GNP) (0.5, 2 and 5 vol.-%) composites was investigated using a Rockwell indenter with normal applied loads ranging from 1 to 200 N. The alumina-GNP composites behaved differently during scratch testing depending on the normal applied load. The coefficient of friction of the composites did not change much at low normal loads but increased with increasing amount of GNP in the alumina matrix for high normal loads. The addition of GNP contributed to improved scratch resistance of alumina nanocomposites only for low loads below ,97 N. This correlates with the mechanical properties of the composites. As the applied load increased, the scratch resistance of the GNP composites decreased due to the presence of weakly bonded grain boundaries in the alumina matrix, which enhanced chipping of material.

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Tribological properties of silica–graphene nano-platelet composites

Cited by 83 publications

References 23 publications

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Boron nitride nanosheets reinforced glass matrix composites

Scratch behaviour of graphene alumina nanocomposites

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Tribological properties of silica–graphene nano-platelet composites

Cited by 83 publications

References 23 publications

Ultrathin graphene tribofilm formation during wear of Al2O3–graphene composites

Ultrathin graphene tribofilm formation during wear of Al2O3–graphene composites

Boron nitride nanosheets reinforced glass matrix composites

Scratch behaviour of graphene alumina nanocomposites

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Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites