Preparation and interfacial layer microstructure of multilayer heterogeneous composite

The appropriate hetero interfacial layer structure between metal and ceramic matrix composites is a very interesting topic in materials science. In this work, an adaptive diffusion reactive interfacial layer composed of “Mo–Mo 2 C–Mo 5 Si 3 –MoSi 2 –SiC” between Mo and SiC f /SiC composite is successfully prepared by chemical vapor infiltration (CVI). This reactive interfacial system is among three possible structures of interfacial layers predicted by Density-functional theory (DFT) calculations, which has the largest total interfacial energy (5.679 J/m 2 ). At the same time, the formation process of the reaction interface layers is elucidated by thermodynamic calculations . In addition, dislocations are observed in Mo 5 Si 3 and Mo 2 C grains, and it is worth mentioning that the Mo 5 Si 3 grains are broken through dislocation movement to form fine grains, which release the residual thermal stress of the interfacial layer system caused by thermal mismatch during the long-term CVI process. Overall, our work provides a practical strategy for developing multilayer heterogeneous composites.