engleski

Hybrid microwave sintering of alumina ceramics which contain waste alumina

The use of microwave energy to sinter ceramic materials offers benefits compared to conventional sintering methods. Some of benefits regarding to less time consumption, achieving high heating rates, and saving energy. The hybrid microwave sintering because of its advantageous is a method of wide interest for improving the microstructure of sintered materials. In this study, the goal was to investigate the influence of the hybrid microwave sintering because on the properties of alumina ceramics, which contain a considerable amount of waste alumina powder. The study was limited to hybrid microwave sintering of alumina green bodies in which the grain growth and densification were characterized. The waste alumina powder, which is generated during machining of alumina green compacts and high- purity (99.9 %) alumina powder, were used as starting materials. The Alumina green bodies were obtained by the slip casting process. The dried green samples were then sintered by using a hybrid microwave furnace. The used hybrid microwave sintering atmospheric furnace consists of a 2.45 GHz microwave generator with a continuously adjustable power output from 0 to 3 kW and external heating elements. The sintered samples with addition of waste alumina powder were exhibited higher density values, slightly larger grain size, and linear shrinkage in comparison with the samples made of pure alumina powder. The observed microstructure for both samples was uniform with the average grain sizes smaller than 2 microns as a consequence of a hybrid microwave sintering.

hybrid microwave sintering, waste alumina powder, recycling, morphology

nije evidentirano