Surface characterization of copper metal matrix composites reinforced with tungsten and molybdenum (Cu-W-Mo) through Microwave hybrid heating: A sustainable approach

Abstract

This study explores the innovative application of microwave hybrid heating (MHH) as a cost-effective and efficient method for fabricating advanced copper (Cu) powder-based metal matrix composites (MMCs). These composites are reinforced with tungsten (W) and molybdenum (Mo) powders at varying weight fractions (5 %, 10 %, and 15 %). The novelty of this research lies in the use of MHH, which combines microwave and conventional heating to achieve uniform, rapid processing, significantly reducing melting times and enhancing material properties. Using a microwave frequency of 2.45 GHz and a power setting of 900 W, pure Cu was successfully cast in just 7 min, while the reinforced composites melted even faster, within 4 min. Phase analysis was conducted using X-ray diffraction (XRD), which revealed the formation of Cu₆₄O phases due to the process taking in the atmospheric environment. Microstructural studies further highlighted the presence of equiaxed grains and uniform dispersion of the W and Mo reinforcement particles throughout the Cu matrix. Increasing W and Mo content in Cu enhances the tensile strength and resistivity of the composite material. The MMC containing 15 % W and 15 % Mo achieved a Vickers microhardness value of 302.78 ± 15.13 HV which is 5.09 times higher than that of pure Cu. The composites exhibited excellent physical properties, including minimal porosity (less than 1.5 %). The Cu + 15 %W + 15 %Mo composite achieved an impressive relative density of 98.56 %, indicating excellent compaction and low defect levels. Moreover tensile strength of Cu + 15 %W + 15 %Mo was found 301 ± 15.05 MPa which was 1.65 times higher than that of pure Cu.