Influence of cobalt, iron and copper on microstructure and mechanical properties of alumina/SiC nano-ceramic composite

Abstract

The silicon carbide reinforced alumina ceramic composite exhibits better physical properties at elevated temperatures. It is a better alternative to monolithic alumina composite; however, achieving homogeneous distribution of constituents and better metallurgical bonding is a major challenge while producing these composites. In the present study, alumina/SiC nano-composites have been developed by mixing metallic powder particles—copper (44 μm and 10 vol%), iron (50 μm and 10 vol%), and cobalt (37 μm and 5 vol%) as fillers materials. Two different nano composite (alumina/SiC and metallic particles) mixtures—ball milled (time: 36 h at 120 rpm) and un-milled were sintered through microwave hybrid sintering process at 2.45 GHz and 2800 Watt. The influences of ball milling on intermolecular bonding in the sintered composites have been investigated through micro-structural characterization of the produced sintered parts. Significant influence of the metallic filler materials and ball milling of composite mixture have been observed on homogeneity. The micro indentation hardness data revealed that micro indentation resistance of the ball milled composites have improved as compared to the un-milled composite.