| Bulk copper, copper-graphene and copper-graphite composites were produced from copper-thermally expanded graphite (TEG) powder mixtures with 0-3 wt.% TEG contents via modified powder metallurgy process that includes powder milling in a planetary mill at 350 rpm for 5 hours, compaction, and vacuum annealing at 1030 œC for 1 hour. Phase composition and microstructure of the composites were analyzed by XRD and SEM techniques. According to Raman spectroscopy, TEG transforms into a few layer graphene flakes in case of composites with 0.1-1 wt.% of carbon additive, while for 3 wt.% of carbon additive it remains in the form of graphite. The addition of 0.1 wt.% TEG results in the tensile strength increase up to 160 MPa (from 93 MPa for pure copper specimen synthesized via the similar synthesis route). Vickers hardness obtained for Specimens under the study is independent from the composite composition. |
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