Papers by Author: R. Horváthová

Abstract: The present paper deals with the nano-indentation of SiC-micro and Si3N4/SiCmicro/ nano ceramic materials. The investigated SiC-micro and Si3N4/SiC-micro/nano ceramics were prepared by liquid phase sintering. Liquid phase was formed from different sintering additives (Y2O3, Yb2O3, Sm2O3). In the case of Si3N4/SiC-micro/nano ceramics the SiC nano-grains were created from SiNC amorphous powder. SiNC precursor decomposed to SiC and Si3N4 particles during sintering. The comparison of nano- and macro-hardness of investigated ceramic materials showed that nano-hardness is significantly higher. The indentation modulus correlated with the measured nano-hardness. Remarkable influence of grain boundaries and SiC nano-inclusions on hardness was observed.