Influence of the Microstructure on Macro/Micro versus Nanohardness of SiC Ceramics

Abstract:

The influence of microstructural variations on the macro/microhardness, nanohardness and Young`s modulus of liquid phase sintered silicon carbide (LPS SiC) has been observed. In order to modify the microstructures some samples were further heat treated at 1850°C for 5 hours to promote grain growth. The depth-sensing indentation tests of SiC materials were performed at several peak loads in the range 10-400 mN. For a better assessment, the indentation values of hardness and Young`s modulus modulus of SiC matrix were also compared to the hardness and Elastic modulus of individual SiC grains. The comparison of macro/micro and nanohardness showed that nanohardness was significantly higher, generally by 6-7 GPa. The nanohardness of individual plate-like SiC grains was around 2 GPa higher than nanohardness of SiC matrix.

• Periodical: Key Engineering Materials (Volume 606)
• Pages: 197-200
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.606.197
• Online since: March 2014
• Authors: Alexandra Kovalčíková*, Ján Dusza, Pavol Šajgalík
• Keywords: Elastic Modulus, Hardness, Heat Treatment, Microstructure, Nanoindentation, Silicon Carbide (SiC)

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