Synthesis and consolidation of nano-sized Cu coated SiC powders by a chemical method and spark plasma sintering

Cu-70 vol% SiC composites with dense microstructure and sound interface between Cu and SiC grains were fabricated by solution chemistry route and spark plasma sintering. Two methods for developing powder mixtures of Cu and uncoated or pre-coated SiC were compared on the basis of the resulting microstructures. The pre-coating of Si(Al)OC onto SiC powders was prepared by curing and pyrolysis of Al-modified polycarbosilane. SiC/Cu composites were obtained by hydrogen reduction and densified using spark plasma sintering of pre-coated SiC and Cu-nitrate powder mixtures. The powder mixture showed a homogenous dispersion of nano-sized Cu particles on the surface of SiC powers. Microstructural observation revealed that the sintered composite using powder mixture with pre-coating of Al-PCS onto SiC powders showed dense microstructure and good contact between Cu and SiC grains due to the improved wettability by barrier coating. The results suggested that the SiC/Cu composite with required microstructural characteristics can be fabricated by using Al-PCS coated SiC powder mixture, more effectively.