In-situ sintering studies on nano-alumina

The optimization of the sintering process becomes nowadays a very important step towards obtaining improved quality ceramics for applications into many industrial areas. Recently, a thermooptical measuring device (TOM) has been developed to in-situ monitor the thermal diffusivity, shrinkage and light scattering of materials during sintering. In present work the TOM method has been used to identify the temperature boundary between different stages of sintering of nano-alumina and to measure the diameter of the sintering necks formed during the incipient stages of the consolidation process. The initial nanopowders have been characterized for particle size by the TEM method. The nano-crystalline powders were sintered into the TOM device in a temperature range between room temperature and 1300°C, with a heating rate of 12°C/min. Interrupted sintering experiments were performed by TOM and Microwave Sintering followed by microstructural observations.