Microstructural, mechanical and thermal properties of microwave sintered Cu-MWCNT nanocomposites

Cu nanocomposites reinforced with 0–6 vol% MWCNTs are fabricated using mixing, ball milling and microwave sintering techniques. It is found that decreasing the Cu powders size from 65 to 15 μm significantly enhances the mechanical and thermal properties of the fabricated nanocomposites. In addition, the optimal MWCNTs content in such composites is found to be 4 vol%; there exists maximum for microhardness, bending strength and thermal conductivity of Cu- MWCNT composites which rise to 82.2 HV, 155.2 MPa and 380.2 W.mk⁻¹, respectively. However, the nanocomposites properties then fall to 75 HV, 139.5 MPa and 315.4 W.mk⁻¹, respectively, with further increasing the MWCNT content up to 6 vol%. Furthermore, the relative density of the pellets is calculated using Archimedes method, demonstrating a lower relative density for the composites with higher MWCNTs content. These findings provide a simple and effective sintering method for the engineering of low-cost metal matrix composites.