SiC nanofiber-reinforced Ag matrix composites exhibiting high strength and ductility

In this work, we demonstrated an example of leveraging the intrinsic morphology features of one-dimensional SiC nanofiber (SiC_nf) to design high-performance Ag-metal matrix composites (MMCs) using powder metallurgy techniques. To break up the SiC_nf agglomerates and increase surface functionality while maintaining its integrity, the raw SiC_nf underwent a specially developed surface modification process. Following a combination of hetero-agglomeration, spark plasma sintering and hot extrusion, the SiC_nf was homogeneously dispersed and singly aligned throughout the Ag matrix. Microstructure observations revealed close contact between the SiC_nf and the Ag matrix, resulting in a sawtooth-like SiC_nf-Ag interface induced by the plastic flow of Ag. Thanks to the presence of strong mechanical anchors at SiC_nf protrusions, the load transfer efficiency of the SiC_nf-Ag interface reached 72 %. Consequently, the SiC_nf/Ag composite exhibited a high tensile strength of 219 MPa and a substantial failure elongation of 39.2 %. This work underscores the importance of optimizing interfacial microstructures and offers the new insights of designing novel Ag-MMCs for applications in conductive devices.