The role of powder preparation route on physical and mechanical properties of Cu-rGO bulk nanocomposites

Abstract To study the effect of the production method on physical and mechanical properties of Cu-rGO nanocomposites, nanocomposite powder samples with rGO content of 0.25–1 wt.% were prepared via combined routes of molecular-level mixing (MLM) and powder metallurgy (PM). Spark plasma sintering (SPS) was applied to consolidate nanocomposite powders with better control on the grain size. According to the specific electrical resistivity measurements, microhardness, and pin-on-disk wear tests, the sample with 0.5 wt.% rGO comprised the best overall properties. For assessment, samples containing 0.5 wt.% rGO were also produced via PM and MLM routes, separately. The physical and mechanical properties of the latter ones were compared with the respective sample already prepared via the combined routes of MLM and PM. The results showed that the electrical conductivity of the nanocomposites produced via different methods was about 10% less than that of the unreinforced copper sample. However, in presence of rGOs, microhardness of the samples increased up to 33%, and coefficient of friction (COF) of the samples decreased from 0.75 to 0.23. Considering the overall behavior of all prepared samples, although MLM route provides more proper distribution of rGOs in copper matrix, it was concluded that Cu-rGO nanocomposites can be produced via the combined routes of MLM and PM in shorter time and at lower price.