Laser additive manufacturing bulk graphene–copper nanocomposites

Abstract

The exceptional mechanical properties of graphene make it an ideal nanofiller for reinforcing metal matrix composites (MMCs). In this work, graphene-copper (Gr-Cu) nanocomposites have been fabricated by a laser additive manufacturing process. Transmission electron microscopy (TEM), x-ray diffraction (XRD) and Raman spectroscopy were utilized to characterize the fabricated nanocomposites. The XRD, Raman spectroscopy, energy dispersive spectroscopy and TEM results demonstrated the feasibility of laser additive manufacturing of Gr-Cu nanocomposites. The microstructures were characterized by high resolution TEM and the results further revealed the interface between the copper matrix and graphene. With the addition of graphene, the mechanical properties of the composites were enhanced significantly. Nanoindentation tests showed that the average modulus value and hardness of the composites were 118.9 GPa and 3 GPa respectively; 17.6% and 50% increases were achieved compared with pure copper, respectively. This work demonstrates a new way to manufacture graphene copper nanocomposites with ultra-strong mechanical properties and provides alternatives for applications in electrical and thermal conductors.

Rapid manufacturing of copper-graphene composites using a novel rapid tooling technique

“…After magnetic stirring, the composite powder was dried for 2 h at 60°C using a vacuum oven. Similar Cu-Gn powder blending method was used by Hu et al (2017) for the fabrication of Cu-Gn composite. However, binders were not involved in the present study to avoid any impurities.…”

“…However, the addition of binders and composite fillers lowered down the reflectivity of laser energy from the copper powder. Hu et al (2017) investigated the fabrication of Cu-Gn composites using customized laser additive manufacturing machine with the assistance of binders. Cu-Gn powder along with PVA (polyvinyl alcohol) was mixed using magnetic stirring in deionized water and sintered layer-by-layer by the laser after drying the powder.…”

“…In the literature survey, it has been found that the addition of graphene as reinforcement in the metal-matrix composite improved the mechanical and tribological characteristics of the pure copper without diminishing the electrical and thermal properties. Few investigations (Hu et al , 2017) has been performed to fabricate free-form parts of Cu-Gn composites by customized laser additive manufacturing technique. However, no other work has been reported to fabricate free-form shapes of Cu-Gn composites by using rapid manufacturing technique.…”

Electropolishing and Shaping of Micro-Scale Metallic Features

“…In work by Hu et al [ 158 ], graphene-reinforced copper matrix composites were fabricated using a laser adaptive process. A 4140 structural steel plate was used as a substrate with dimensions of 10 mm × 8 mm × 2.5 mm, the copper powder having a diameter <10 μm, and multi-layer COOH-rich graphene nano-platelets with average diameters <2 μm were used.…”

“…Electropolishing is crucial for TEM preparation investigations of the micro-structure of materials and their crystallinity at a micro-nano-level, the stability of passive films, chemical homogeneity, and the composition of various alloys [ 11 , 58 , 61 , 158 ]. It is very suitable for preparing thin metallic foils (~100–150 nm) for TEM analysis [ 59 ].…”