Abstract
In this paper, plain aluminum was chosen as matrix alloy and graphene reinforced aluminum alloy composites was successfully prepared via powder metallurgy approach. Micro-milling experiments were conducted to explore the effect of varying graphene nanoflakes (GNFs) content (0.5%, 1.0%, and 1.5% by weight) on the machinability of composites and their machining results were compared with that of plain aluminum. Chip morphology, milling force, and machined surface morphology were used as the machinability measures. Experiment results showed that when the content of GNFs is less than 1.5%, the grain refinement of GNFs plays a major role. The hardness and density of the composites are increased. When the content of GNFs is more than 1.5%, the agglomeration phenomenon is obvious, which reduces the hardness and density of the composites. Micro-milling results show that the milling force is the highest when the GNFs content is 1%, and curling degree of chips increased as FPT increase for a certain content of graphene of composites. Furthermore, when the content of GNFs in composites is more than 1%, the surface roughness of milling grooves is greatly improved, which may be related to the lubrication of graphene and the formation of continuous chips.
Highlights
Metal matrix composites (MMCs), light metal matrix composites such as aluminum and magnesium have been considered as one of most promising materials in aerospace, electronic packaging, and automotive industries owing to their superior properties such as higher strength-to-weight ratio, lower thermal expansion coefficient and higher resistance to thermal fatigue and creep [1,2,3,4,5,6]
Milling forces represent an important factor of machinability evaluation: higher milling forces means higher stresses on the tool, causing wear and vibrations and higher stresses on the material causing more damage at higher depth from the machined surface
Two transition points are 0.75 μm and 1.0 μm respectively which could be explained as minimum chip thickness (MCT) point and size effect point for micro-milling
Summary
Metal matrix composites (MMCs), light metal matrix composites such as aluminum and magnesium have been considered as one of most promising materials in aerospace, electronic packaging, and automotive industries owing to their superior properties such as higher strength-to-weight ratio, lower thermal expansion coefficient and higher resistance to thermal fatigue and creep [1,2,3,4,5,6]. Arora [29] studied the effect of graphene platelet loading on the machinability of epoxy-based graphene platelets composites by conducting micro-milling experiments on composites with varying graphene platelets content and their results were contrasted against that of plain epoxy. Aluminum matrix composites are commonly used in high precision parts, such as engine cylinder liner and avionics components For this reason, material removal behavior of the composite needs to be well understood and the choice of processing parameters are of great significance for improving machining accuracy and surface quality. Micro-milling process was chosen for investigating the machinability of graphene nano-flakes reinforced aluminum alloy (GNFs/Al) composites since their key process parameters such as edge radius of the tool and chip load are at the microscale [29].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
