Microwave Assisted Sintering of Some Copper Based Nano-Composites and its Evaluation

In the present investigation Cu₉₉Cr₁, Cu₉₄Cr₆, Cu₉₉Cr₁-4% SiC and Cu₉₄Cr₆-4% SiC nanocomposites were synthesized for thermo-electric applications. SiC particulates (purity >;96.0%, ~30 nm size) was ball milled with copper-chromium (purity >;99.0 %) mixtures for 50 h in stainless steel grinding media. The uniaxially pressed compact specimens were subjected to microwave sintering 900°C, 30 min and conventional sintering 900°C, 1 h. The microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The mechanical properties like Vickers hardness and wear resistance, and electrical conductivity of the sintered specimens were also investigated. In the present investigation, the best combination of mechanical properties and electrical conductivity were obtained for the microwave sintered specimens compared to conventional sintered compacts. This is possibly due to the enhanced densification achieved through microwave sintering technique.