Comparison between conventional, vacuum and microwave sintering of Cu-Cr-4 wt.% SiC nanocomposites

Attempts have been made to synthesize Cu₉₉Cr₁, CU₉₉O₁-4 wt.% SiC nanocomposites for thermo-electric applications. The blend compositions were ball-milled for 50 h in a stainless steel grinding media. The compact specimens were subjected to vacuum sintering (900°C and 1000°C for lh), conventional sintering (900°C and 1000°C for 1h) and microwave sintering (800°C, 900°C and 1000°C) duration of 30 min using a furnace of 2.45 GHz frequency and 900 W power. The micro-structural characterization was carried out by X-ray diffraction and scanning electron microscopy. The mechanical properties like Vickers hardness 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. This is possibly due to the enhanced densification achieved through microwave sintering technique. Possible sintering characteristics and strengthening mechanisms were analyzed.