Experimental Investigation of the Machinability of Epoxy Reinforced With Graphene Platelets

Abstract

The objective of this research is to study the effect of graphene platelet (GPL) loading on the machinability of epoxy-based GPL composites. To this end, micro-milling experiments are conducted on composites with varying GPL content and their results are contrasted against that of plain epoxy. The material microstructure is characterized using transmission electron microscopy and scanning electron microscopy methods. Chip morphology, cutting force, machined surface morphology, and tool wear, are employed as the machinability measures for comparative purposes. At lower loadings of GPL (0.1% and 0.2% by weight), the deformation of the polymer phase plays a major role; whereas, at a higher loading of 0.3% by weight, the GPL agglomerates and interface-dominated failure dictates the machining response. The minimum chip thickness value of the composites decreases with an increase in GPL loading. Overall, the 0.2% GPL composite has the highest cutting force and the lowest tool wear.

Experimental investigation on micromachining of epoxy/graphene nano platelet nanocomposites

“…When the GNP content exceeds 0.3 wt%, GNP agglomeration will happen in the matrix material. Arora et al [29] observed microcracks/fragments which were caused by the tool feed at the GNP agglomeration regions. The microcracks around the GNP agglomeration regions caused changes to the cracks on the machined surface.…”

“…This increase in lubrication properties may have cancelled out the effect of the increased overall strength and modulus of the epoxy/GNP nanocomposites. Another factor is that the presence of regions of GNP agglomeration means that the cutting force declines with increased GNP content [29]. The increase in cutting force is caused by overall strength and modulus.…”

“…Thus, it is important to explore the edge Fig. 12 SEM micrographs of micromachined slots for plain epoxy and epoxy/GNP nanocomposites chipping either by developing strategies for its minimization or applying new post-processing technology for edge chipping [29,46]. Figure 12 shows up and down milling slot edges from the up and down milling of plain epoxy and epoxy/GNP (0.1 wt% and 1.0 wt%) nanocomposites at 4 levels of FPT (0.1, 0.5, 4.0, 6.0 μm).…”

“…The tool ploughs out the material, and the elastic recovery will dominate the material deformation, and no chips will be formed in each tool path [25][26][27][28]. When the uncut chip thickness is below a critical value, the size effect can have negative effect on the cutting process, such as higher cutting force, shorter tool life and worse dimensional surface quality [21,29]. Hence, the ploughing area will directly affect the surface topography of the material and make the cutting force increase.…”

Influence of Functionalized Multi-Walled Carbon Nanotubes on the Mechanical Properties and Delamination in Drilling of CFRP Composites

“…Hence, less damage occurs during drilling leading to lesser delamination [21]. Another reason for a decrease in delamination on addition of MWCNTs can be attributed to the fact that the chip formation is aided when MWCNTs are added, due to the formation of nanotube agglomerates causing less friction between the tool edge and CFRP laminates [43]. …”