In situ indentation behavior of bulk multi-layer graphene flakes with respect to orientation

Rudolf, Chris; Boesl, Benjamin; Agarwal, Arvind

doi:10.1016/j.carbon.2015.07.070

Cited by 21 publications

(13 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These energy dissipation mechanism of GNP lead to improved fracture toughness of ceramics as observed in our previous study. 23,31 Figure 1(c) shows fracture surface of aluminum oxide-5G. The overall structure is dense; however severe GNP agglomeration is observed which is attributed to its poor dispersion at high concentration of 5 vol.%.…”

Section: Microstructurementioning

confidence: 99%

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Zhangcheng¹,

NietoAndy²,

AgarwalArvind³

2016

Nanomaterials and Energy

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Microstructurementioning

confidence: 99%

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Zhangcheng¹,

NietoAndy²,

AgarwalArvind³

2016

Nanomaterials and Energy

Self Cite

View full text Add to dashboard Cite

show abstract

“…The hardness values, on the contrary, are lower in the "in-plane" surfaces and higher in cross-sections [8]. This difference is again related to the microstructural anisotropy due to the GNP's geometry and preferential orientation, which favor delamination of the GNPs when the indenter hits the "in-plane" surface [14].…”

Section: Introductionmentioning

confidence: 99%

Spark Plasma Sintered Zirconia Ceramic Composites with Graphene-Based Nanostructures

et al. 2018

View full text Add to dashboard Cite

Abstract:The addition of graphene-based nanostructures (GBNs) can improve the inherent fragility of ceramics and provide them with improved electrical and thermal conductivities. However, both the starting material (ceramic matrix and GBNs) and the processing/sintering approach are crucial for the final composite microstructure and properties. This work focuses on the influence of the content and dimensions of the GBN filler (10 and 20 vol%; 3 and~150 layers), the powder-processing conditions (dry versus wet), and the homogenization method (ultrasound sonication versus high-energy planetary ball milling) on GBN/tetragonal zirconia (3YTZP) composites. The microstructure and electrical properties of the spark plasma sintered (SPS) composites were quantified and analyzed. The highest microstructural homogeneity with an isotropic microstructure was achieved by composites prepared with thicker GBNs milled in dry conditions. A high content (20 vol%) of few-layered graphene as a filler maximizes the electrical conductivity of the composites, although it hinders their densification.

show abstract

“…Graphene, an allotrope of carbon, is a two-dimensional sheet of sp 2 bonded carbon atoms [1,3,4,5]. Due to the difficulty and cost attributed to isolating the single layered graphene, multi-layered graphene such GNP are commonly used [4,6].…”

Section: Graphene Nanoplatelets (Gnp)mentioning

confidence: 99%

“…Due to the difficulty and cost attributed to isolating the single layered graphene, multi-layered graphene such GNP are commonly used [4,6]. GNPs consist of 10-30 sheets of graphene with a thickness of 6-8 nm, with weak Van der Waals forces in between the 2D layers [4,5,7]. Though multilayered, GNP retains many of the desirable mechanical, thermal and electrical properties found in single-few layer graphene [3].…”

Section: Graphene Nanoplatelets (Gnp)mentioning

confidence: 99%

See 1 more Smart Citation

Deposition of Copper Nanoparticles on 2D Graphene NanoPlatelets via Cementation Process

Fontoura¹

View full text Add to dashboard Cite

In situ indentation behavior of bulk multi-layer graphene flakes with respect to orientation

Cited by 21 publications

References 20 publications

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Spark Plasma Sintered Zirconia Ceramic Composites with Graphene-Based Nanostructures

Deposition of Copper Nanoparticles on 2D Graphene NanoPlatelets via Cementation Process

Contact Info

Product

Resources

About

In situ indentation behavior of bulk multi-layer graphene flakes with respect to orientation

Cited by 21 publications

References 20 publications

Ultrathin graphene tribofilm formation during wear of Al2O3–graphene composites

Ultrathin graphene tribofilm formation during wear of Al2O3–graphene composites

Spark Plasma Sintered Zirconia Ceramic Composites with Graphene-Based Nanostructures

Deposition of Copper Nanoparticles on 2D Graphene NanoPlatelets via Cementation Process

Contact Info

Product

Resources

About

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites

Ultrathin graphene tribofilm formation during wear of Al₂O₃–graphene composites