IN-SITU STUDY ON SiC-Si INTERFACIAL BONDING STRENGTH OF REACTION BONDED SiC/Si COMPOSITES

摘要

3C-SiC, 6H-SiC and a-Si phases were observed in a reaction bonded SiC/Si composite (RBSC). Micro structural characterization indicates that Si phases form a network surrounding SiC particles and there are residual a-Si distributed at the vicinity of the grain boundaries in addition to single crystalline Si. Desired nano-scale tensile specimens of SiC-Si were successfully prepared by Ga focused ion beam (FIB) and a homebuilt in-situ tensile test device was accommodated inside an FE-SEM. Interfacial mechanical properties of RBSC were for the first time measured and the average SiC-Si interfacial strength was found to be 1588 MPa, consistent with the strength of amorphous Si. Localized amorphous interfacial structure was further confirmed by HRTEM.