RESUMEN
The microstructure and resistivity of AIN/BN ceramic nano-composites and micro-composites were investigated. The results showed that because the nano-BN crystals were homogeneously dispersed around the AIN grains of the matrix, the conductive glass phase surround AIN grains were separated, and it was difficult to form the electric conductible consecutive passageway (than micro composites), the leakage conductance of nano-composites was far lower than micro-composites.
RESUMEN
Ceramizable composite is a kind of polymer matrix composite that can turn into ceramic material at a high temperature. It can be used for the ceramic insulation of a metal conductor because of its processability. However, poor low-temperature ceramization performance is a problem of ceramizable composites. In this paper, ceramizable composites were prepared by using silicone rubber as a matrix. Ceramic samples were sintered at different temperatures no more than 1000 °C, according to thermogravimetric analysis results of the composites. The linear contraction and flexural strength of the ceramics were measured. The microstructure and crystalline phase of ceramics were analyzed using scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that the composites turned into ceramics at 800 °C, and a new crystal and continuous microstructure formed in the samples. The flexural strength of ceramics was 46.76 MPa, which was more than twice that of similar materials reported in other research sintered at 1000 °C. The maximum flexural strength was 54.56 MPa, when the sintering temperature was no more than 1000 °C. Moreover, glass frit and nano silica played important roles in the formation of the ceramic phase in this research. A proper content of nano silica could increase the strength of the ceramic samples.