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This study investigates the effect of heating mode on the sintering of Copper-SiC metal matrix composites containing up to 7.5 wt.% SiC. The sinterability of the Cu-SiC system consolidated in a 2.45 GHz multimode microwave furnace has been critically compared with that processed in a radiatively heated (conventional) furnace. As compared to conventional sintering, microwave processing has resulted in a greater densification. It was observed that an increase in SiC content resulted in a higher hardness of the materials for both the heating modes. For all compositions, the electrical conductivity and hardness of microwave-sintered Cu-SiC composites are higher than those of their conventionally sintered counterparts.

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In this investigation, copper–TiB2 metal matrix composites were fabricated by spark plasma sintering. The effect of TiB2 (2.5, 5, 7.5, and 10 wt.%) additions on the microstructural, electrical, and mechanical properties of the composites was investigated. There was a remarkable reduction in processing time and temperature by this process as compared to conventional sintering. Scanning electron microscopy with energy dispersive X-ray spectroscopy elemental maps revealed a homogeneous distribution of TiB2 in the copper matrix. The hardness of the composites exhibited no consistent trend with the addition of TiB2. An improvement in tensile strength was observed at the expense of ductility. Electrical conductivity showed a decreasing trend. Morphology of the fracture surfaces was analyzed to predict the nature of failure under tensile load.

Copper MMCs reinforced with graphene, SiC and graphite flakes with varying mass fractions of 2.5, 5, and 7.5 wt% SiC, 2.5, 5, 7.5, and 10 wt% graphite and 0.2, 0.4, 0.6 and 0.8wt% graphene particles were fabricated through powder metallurgy route. The powder mixtures were blended and then compacted under a uniaxial pressure of 400MPa for both Cu-SiC and Cu-Gr composites and 600Mpa for Cu-Gn composites. Green compacts were sintered by microwave (MW) sintering process. MW sintering was performed at 950°C in open atmosphere with a heating rate of 25°C/min for all composites. Densification parameter (DP) was determined for all MMCs and a reduction in DP values were observed with an increase in weight percentage of reinforcement particles as a result of increase in porosity. Higher mass fractions of reinforcement particles in the Cu matrix tend to offer a diffusion barrier to copper atoms. Micro-structural analysis was performed using Optical and scanning electron microscope which revealed a homogeneous microstructure of all composites at low mass fractions of Sic, graphite and graphene. In order to detect the presence of any oxides of Cu and other elements, EDS analysis was carried out. Hardness data showed an increasing trend for Cu-SiC and Cu-Gn composites and a declining trend for Cu-Gr composites. Porosity has a significant effect on the electrical conductivity values of the composites.