Sintering Behavior, Microstructure, and Mechanical Properties: A Comparison among Pressureless Sintered Ultra-Refractory Carbides
Figure 3
(a) SEM micrographs of the polished surface of ZC20; the bright phase is ZrC, the grey phase is MoSi2, the dark irregular particles are SiC, whilst the little rounded dark ones are residual porosity. (b) BSE-SEM image of the fracture surface showing a 15 μm-thick SiC layer on the edge of ZC20. (c) Zr-Si phases at the interface ZrC-MoSi2. Darker regions correspond to Si-richer ZrxSiy phases. (d) Wetted grain boundaries and Zr-Si phases with different stoichiometry indicating local crystallization from liquid phase. (e) BF-TEM image of ZC20 composite showing the formation of SiC on Zr2Si phase.
