Scratch behaviour of graphene alumina nanocomposites

Abstract

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.

Graphene reinforced metal and ceramic matrix composites: a review

“…Alumina ceramics have been the most widely studied matrix material in GNP-CMCs [22,23,28,30,[35][36][37]39,63,70,115,[133][134][135][136][137][138][139][140][141][142][143][144][145][146][147][148] owing to their wide use as structural ceramics in automotive, aerospace and biomedical applications. The first study on GNP-CMCs was on Al 2 O 3 -GNP composites by He et al [28] where it was seen that GNPs could be successfully incorporated into a ceramic matrix and consolidated by SPS.…”

Experimental and Simulation Studies of Temperature Effect on Thermophysical Properties of Graphene-Based Polylactic Acid

“…This effect reaches a maximum at 6 wt% GNP, where the value of COF is 2.49 compared with 1.45 measured for the pure PLA matrix, which corresponds to about 72% of improvement for the coefficient of friction at scratch. Most likely, it is due to the enhanced tangential force ( Fx ) in nano-reinforced structures, which in turn leads to higher COF, as also observed by Porwal et al [ 44 ].…”

Measurement of hardness and friction properties of pencil leads for quantification of pencil hardness test

“…Therefore, the research tends to focus on material plows of scratch hardness, rather than on the scratch behaviour of a coating, for quantitative evaluation. 12,13 To better understand the results of pencil hardness test, it is important to confirm the characteristics of pencil leads. We believe that we are able to quantify the pencil hardness value compared to the indention hardness value with increasing clay content in pencil leads.…”

“…Therefore, the research tends to focus on material plows of scratch hardness, rather than on the scratch behaviour of a coating, for quantitative evaluation. 12,13…”