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 mu m 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. (C) 2020 Elsevier B.V. All rights reserved.