In-situ preparation of nano MoSi2[sbnd]SiC composite by melt infiltration of silicon method.

The dual-phase and in-situ MoSi 2 SiC composite were prepared by melt silicon infiltration method, in which the SiC phase dispersed in the MoSi 2 matrix. The results show that the matrix and reinforcement phase of this composite are all in nanometer scale, and the composite is dense and no oxygen content, also the matrix MoSi 2 is even occurred preferring orientation in the (211) lattice plane. Furthermore, there are lots of stacking faults and some dislocations in this composite. And this in-situ composite possesses higher strength owing to its transgranular fracture morphology. It is clear that the resistivity of composite is increased with the increasement of SiC content and its resistivity simulation also confirmed that the composite own very fine and dispersed SiC phase. After oxidation at 1300 °C for 3 h, the mass gain of this composite would keep unchanged; this means a passivation stage is gained. When the oxidized samples are used to oxidize again at low temperature as 500 °C, the “PEST” is no longer observed. [ABSTRACT FROM AUTHOR]