Microstructure and thermal expansion behavior of a novel Cf-SiCNWs/AZ91D composite with dual interface

In this study, a novel composite with dual interface, namely T-700 carbon fibers grafted with SiCNWs reinforced AZ91D (C-f-SiCNWs/AZ91D), was designed. The microstructure of the C-f-SiCNWs/AZ91D composite was fully characterized and its thermal expansion behaviors from 25 to 450 degrees C investigated. The results show that the C-f-SiCNWs/AZ91D has dual interface of C-f/AZ91D and SiCNWs/AZ91D. In the alloy matrix, the nanowires are uniformly distributed without any agglomerates and showing a good bond with the matrix. Near the interface of SiCNWs/AZ91D, considerable dislocations were observed, which can be attributed to the different thermal expansions of SiCNWs and AZ91D matrix. It was found that the thermal expansion behavior of the C-f-SiCNWs/AZ91D composite was significantly influenced by its interfacial configuration, which can reduce the coefficients of thermal expansion and improve the stability of the composite.