Sinterização de alumina e alumina/zircônia em forno convencional e forno micro-ondas.

Abstract

This work aims on establishing an energy microwave protocol that is needed on the Alumina and Alumina/Zirconia syntherization infiltrated with Lantanio glass and with a structure that is adequate in porosity, glass infiltration and mechanical properties when compared to a conventional oven. The samples were glass prepared by slipcasting, and then divided into groups according to the method of curing and glass infiltration. For the microwave oven, the power used was 1,4KW and 1,6KW and times of 10, 15 and 20 minutes for curing, and 20 and 30 minutes for the infiltration process. The samples were subjected to the determination of physico-mechanical properties: porosity, density, flexural strength and Vickers hardness. Microstructural characterization was performed by optical microscopy and scanning electron microscopy with EDS. Regarding burning in the microwave, samples that were submitted to a power of 1,4kW and a period of 20 minutes showed microstructure similar to conventional oven. Quantitative results of infiltration process showed that alumina samples subjected to glass infiltration in the microwave oven (1,6kW and 30 minutes) is similar to those sintered in a conventional oven. For Alumina/Zirconia composite, time was a positively influence, although was not sufficient to prepare a resistant microstructure. It can be concluded that the microwave energy is promising in the dental ceramics process, as it significantly reduces the sintering time keeping physical properties.