Effect of milling time and microwave sintering on the microstructure and micro-hardness of nano-structured Cordierite

The purpose of this research is to investigate the sintering of cordierite (34.86 wt% Al2O3, 51.36 wt% SiO2and 13.78 wt% MgO) nano-grains synthesized by mechanical activation route. Samples were prepared by the high-energyball milling of the starting powders followed by conventional and microwave sintering at 1390°C. SEM observationsillustrated the equiaxed nano-grains of cordierite with an average grain size of 30 nm for samples sintered in microwave.With the increase of milling time, samples sintered at 1390°C in microwave furnace obtained lower porosity, higherdensity and microhardness than those sintered at the same temperature in conventional furnace. Sample milled for 30 hand sintered in microwave furnace at 1390°C obtained the maximum microhardness of 1089±5 kg/mm2.

Keywords:

Microwave , Milling , Micro-hardness , Microstructure , Nano Cordierite